ISOGEOCHEM List

Paleoclimate postdoc opening — EcoClimate Variability Lab, University of Georgia

David Fastovich — 2026-06-17T15:57:33-04:00

Hi all,

I'm hiring a two-year postdoc in the EcoClimate Variability Lab in the Department of Geography at the University of Georgia, and wanted to share it with the list.

The successful candidate will work with me to investigate the forces controlling hydroclimate in eastern North America over the last 21,000 years. The project synthesizes a network of leaf wax hydrogen isotope records from five well-dated lake sediment archives along a latitudinal gradient, using the last deglaciation as a natural experiment to disentangle greenhouse gas, ice sheet, and ocean heat transport forcings on moisture transport and westerly storm tracks. Reconstructed [...]

Re: Measuring d13C in organic solvents

Schimmelmann, Arndt — 2026-06-17T18:40:37+00:00

Hello Oliver,
I never measured isotope ratios in formaldehyde because it is a highly reactive and poisonous gas. Here is a complete list of reference materials from Indiana University:
https://schimmelmann-standards.github.io/pdfs/alphabetical%20list%20of%20all%20reference%20materials%20ADA.pdf
Best wishes,
Arndt

From: Stable Isotope Geochemistry <ISOGEOCHEM@list.uvm.edu> On Behalf Of Oliver Shipley
Sent: Wednesday, 17 June, 2026 11:31
To: ISOGEOCHEM@LIST.UVM.EDU
Subject: Re: [ISOGEOCHEM] Measuring d13C in organic solvents [...]

Silver nitrate silica gel separation of free sterols and stanols

Alessandro Mauceri — 2026-06-17T16:53:07+00:00

Hello all,

I was wondering whether anyone has a protocol for separating free sterols and stanols using silver nitrate-impregnated silica gel flash columns.

I have seen several approaches where separation is performed after derivatization (e.g., acetylated or silylated steroids), but I would prefer to avoid derivatization prior to separation and instead derivatize immediately prior to GC analysis. I would also prefer not to rely on methods that require reversing derivatization steps after separation (though I'll go down that route if needed). [...]

Re: Measuring d13C in organic solvents

Oliver Shipley — 2026-06-17T11:30:58-04:00

Full message available at: Re: Measuring d13C in organic solvents

Xi’an Carbon International Meeting - 2 weeks left before abstract deadline!

Eric Lichtfouse — 2026-06-17T20:07:52+08:00

Full message available at: Xi’an Carbon International Meeting - 2 weeks left before abstract deadline!

Techincal specialist/lab manager wanted!

Walker, Stephanie — 2026-06-17T08:59:04+00:00

Hello Isotope Geochemists!
The University of Exeter is recruiting a Mass Spectrometry Specialist to join our Technical Strategy & Operations team, supporting the Faculty of Environment, Science and Economy. This is a permanent, full-time role (1.0 FTE), based at the Penryn Campus in Cornwall.
The post-holder will be responsible for the day-to-day operation and management of Stable isotope mass spectrometry facility, which include:
Key responsibilities include instrument setup (Sercon Integra 2 and Sercon 20-22), running and troubleshooting, method development, quality control, data interpretation, and supporting researchers and students with analytical approaches. The role also involves facility management, including project scheduling, [...]

Re: Measuring d13C in organic solvents

Schimmelmann, Arndt — 2026-06-16T22:10:34+00:00

Hello Piotr,
The USGS and Indiana University will soon release 10 volatile organic carbon (VOC) stable isotope reference materials, including toluene. Our international team already completed all analyses in several laboratories and we are currently in the process of publishing the results. Indiana University already has another batch of tolunene and other organic volatiles available as reference materials for C and H isotope ratios. Please contact me for additional information.
Best regards,
Arndt

Measuring d13C in organic solvents

Piotr Chibowski — 2026-06-16T17:13:04+02:00

Hi all,
My colleague wants to measure carbon isotopes in dichloromethane,
chloroform, benzen and toluen using a GC-IRMS. I don't know what kind of
samples, but not clean substances, so chromatography is necessary. He asked
me about reference material - there are no available standards. I was
wondering if anyone has done something similar and would be willing to
answer some questions. My idea is to prepare internal standards by
measuring those solvents on a EA-IRMS on chromasorb, what do you think of
this idea?
Cheers,
Piotr Chibowski

Chemical Analysis Engineer position in CSIA, La Rochelle, France

Benoit Lebreton — 2026-06-15T18:02:23+02:00

Hi,

The CNRS is holding an external recruitment competition at the LIENSs
UMR7266 laboratory in La Rochelle, France. The deadline for applications
is July 9, 2026.

This is competition number 85.

We are seeking a Chemical Analysis Engineer to develop methodological
techniques for separating specific compounds (fatty acids, amino acids)
using isotope ratio mass spectrometry by GC-c-IRMS (Compound Specific
Isotope Analysis, CSIA) to determine their carbon and nitrogen isotopic
composition. [...]

Re: High throughput soil grinding

Hill, Brett (AAFC/AAC) — 2026-06-12T22:07:47+00:00

Unclassified / Non classifié

Hi Brynne,

We use a hot dog roller type soil fine grinding system similar to what you described. We don not use stainless steel balls to grind the soil, but two cylindrical steel rods of different diamters.

I will send some pics to the email address in your signature block. [...]

Re: [EXTERNAL] Re: [ISOGEOCHEM] High throughput soil grinding

Stephen Romaniello — 2026-06-12T18:04:05-04:00

If it helps to have key search, what you’re describing sounds like a type of rod mill (as opposed to a ball mill). There are many large industrial examples, but there also seems to be some lab scale models available for sample prep. Eg here: https://m.made-in-china.com/product/Laboratory-Sample-Preparation-Used-Bottle-Roller-Rod-Grinder-Ball-Mill-1905720455.html

Cheers,
Steve

Sent from my iPhone

> On Jun 12, 2026, at 5:47 PM, Lazarus, Brynne E <0000090d338b2133-dmarc-request@list.uvm.edu> wrote:
>
>
> Thank you, Jenny,
>
> This is exactly what I had in mind! I so appreciate you taking the time to point me in the right direction.
>
> Best,
> Brynne
[...]

Re: [EXTERNAL] Re: [ISOGEOCHEM] High throughput soil grinding

Lazarus, Brynne E — 2026-06-12T21:38:47+00:00

Thank you, Jenny,

This is exactly what I had in mind! I so appreciate you taking the time to point me in the right direction.

Best,
Brynne

Re: High throughput soil grinding

Carlson, Jenny Louise — 2026-06-12T20:53:50+00:00

Hi Brynne,

My lab routinely processes large numbers of soils for EA, and yes we do use a "weenie roaster"-style roller! Ours is ancient, but the most similar modern equivalent I see from a quick online search looks like the MRC RJM Series Lab Jar Roller Mill. Ours is much wider and accommodates ~40 small jars, but that product looks like it has optional stacked tiers to increase the smaller working area? [...]

High throughput soil grinding

Lazarus, Brynne E — 2026-06-12T19:44:39+00:00

Hi All,

I am looking for a way to efficiently grind many soil samples to the fine powder needed for combustion in an EA.

If you have a ball mill you are especially happy with or a self-engineered/machine shop crafted device that works well, I would love to hear about it.

I recall once seeing something that looked like a convenience store hot dog roller onto which were placed metal cylinders containing soil samples and stainless steel balls. When the roller turned, the cylinders rotated on it at a rate that allowed the stainless steel balls to grind the soil. [...]

IAEA Isotope Hydrology Symposium 2027 Announcement

MILLER, Jodie — 2026-06-12T09:33:48+00:00

Hello Isotope Hydrology Community,

I am very pleased to announce that the 2027 IAEA Isotope Hydrology Symposium will take place 10-14 May 2027 at the Vienna International Centre, Vienna Austria.

The conference website is available at this link - International Symposium on Isotope Hydrology | IAEA<https://www.iaea.org/events/isih2027>. Key deadlines and the process for submitting an abstract and applying for grant funding are all available on this site. Note that there is no charge to attend the conference but all participant must be registered. [...]

Re: signal loss MAT253 / new ion source cable

Travis Meador — 2026-06-12T03:21:13+00:00

Dear Dorothee,

Regarding the bulbs, there is a small red light that turns on when one of the heat bulbs in the ion source fails. You can see it through the slots of the panel that covers the electronic boards on the MAT 253 - in the upper right corner. Did you see that the light was on before replacing bulbs, and confirm that it was off after switching bulbs? And after replacing the ion source? [...]

signal loss MAT253 / new ion source cable

Dorothee Wilhelms-Dick — 2026-06-09T13:23:47+02:00

Dear Isogeochem Community,

mid of May the ion source cable of one of our MAT253 systems (red cable
feeding the source) was replaced by a new cable.
This MAT253 is connected to an elemental analyzer and ConFlo system.

At the beginning I was happy, since it seemed much easier to get all the
wires properly connected onto the pins / feedthroughs.
We had a bit of trouble with signal stability first, but after a while
everything settled. [...]

Looking for an Instrument Builder at TU Dresden

Paul Fremdling — 2026-06-08T14:12:05+00:00

Dear Colleagues,

I hope this email finds you well. I am reaching out to share a job opportunity within our faculty in Dresden.

We are currently looking for someone to support the setup of a new noble gas mass spectrometry system. The position is a fixed-term contract for approx.16 months.
We are specifically looking for someone with hands-on experience in scientific instrument building. Neither A PhD nor are German skills required - English is perfectly fine. [...]

OS for LGR DLT-100

rasi prasetio — 2026-06-08T15:22:47+07:00

Dear All,

We have an old LGR DLT-100, which was working fine until it wasn't.
We had hardware issues, and we think we solved it with board replacement (I
don't know the details). However, when we wanted to start the system, it
was blank, didn't boot. We want to install a new hard disk but we don't
have the OS to install it.
Does anyone have the resources for this OS? [...]

Re: two different topics: 1.Anti-vibration pads. 2.Regulator/gas station

Benjamin Harlow — 2026-06-05T10:40:33-07:00

Hi Julia-

Getting a regulator with check valve in the CGA fitting or installing a
pigtail with check valve have eliminated any need I have had for purging
regulators. With these in place you have a short amount of time, perhaps a
couple minutes to change a tank without the regulator loosing excessive
pressure or introducing noticeable contamination in your carrier lines. I'm
typically more concerned about adjusting to backgrounds from a new tank
compared to room contamination. In this case, it's good to run your
downstream devices including branch lines at full flow for a bit, and
allowing some [...]

European Dendrofieldweek EDF 2026, Bardonecchia/Italy

Kerstin Treydte — 2026-06-05T14:04:18+00:00

Dear colleagues and friends
This announcement is for those interested in tree rings.

We are happy to announce that the 36th European Dendroecological Fieldweek (EDF) will take place from Fr, August 28 to Fr, September 4, 2026 in Bardonecchia, Italy, in close co-organisation btw the Dendrolabs of WSL and the University of Torino. Details and the registration link can be found here https://www.wsl.ch/dendrofieldweek [...]

Re: two different topics: 1.Anti-vibration pads. 2.Regulator/gas station

Julia Valverde — 2026-06-05T06:08:30+00:00

Hi everyone,

And thank you all for the invaluable information and so many ideas.
As always, this group is full of wonderful people who are generous with their knowledge.

Have a nice weekend and best wishes,
Julia

Re: two different topics: 1.Anti-vibration pads. 2.Regulator/gas station

Tomasz Kuder — 2026-06-04T12:23:14-05:00

Hi Julia,
Another option is to use a thee way valve as suggested previously, and keep
a Trajan/Agilent "big universal trap" downstream from the 3-way (toggling
the valve to purge the regulator volume isolates the trap from ambient
air). The trap volume will keep the instruments fed with helium long enough
to swap the helium tank. There is no air slug in the line if you use this
setup. [...]

Re: two different topics: 1.Anti-vibration pads. 2.Regulator/gas station

Dyke Andreasen — 2026-06-04T10:12:18-07:00

I second Paul’s enthusiasm for switchover manifolds. It has been some time in the past, but I bought just the switchover regulator from Tescom. The rest of the assembly; pigtails (McMaster), and other fittings independently of the regulator were bought from other vendors. it worked out to about half the cost of a packaged system that vendors, like Prostar, offer if you assemble it yourself. [...]

Re: two different topics: 1.Anti-vibration pads. 2.Regulator/gas station

Paul Eby — 2026-06-04T16:01:40+00:00

Julia,

I'm a fan of switchover manifolds (although a bit of an investment): you can hook up two tanks and the system will automatically start drawing from the second tank when the first is empty. Ours also has vent valves for each tank so that you can clear the line after hook up. [...]

Re: two different topics: 1.Anti-vibration pads. 2.Regulator/gas station

Andersen, Jens — 2026-06-04T11:15:21+00:00

Hi Julia.

We have some instruments installed on pneumatic mounts, because we had a time in the past where contractors were using vibration rollers. We also have a quarry next door that blast once or twice a week. They are similar to these:
PLM3 | Fabreeka M12 Anti-Vibration Mount, Pneumatic | RS<https://uk.rs-online.com/web/p/anti-vibration-mounts/0688492?cm_mmc=UK-PLA-DS3A-_-bing-_-PLA_UK_EN_Catch+All-_-Mechanical,+Fluid+Power+%26+Tools-_-688492&matchtype=e&pla-4574999185500285&cq_src=google_ads&cq_cmp=554644865&cq_term=&cq_plac=&cq_net=o&cq_plt=gp&gclid=c2c40259993e1ce76e096878c433b733&gclsrc=3p.ds&msclkid=c2c40259993e1ce76e096878c433b733> and are pumped up with a regular foot pump to around 2 bars once in a while. [...]

LGR N2O analyser spectra fit

Getachew Agmuas — 2026-06-04T09:58:35+02:00

Dear all,

I am measuring N2O isotopes using an N2OIA-23e-EP and am primarily
interested in the δ15N-bulk measurement. The samples are air samples
collected from incubation experiments in which 15N-labeled NH4NO3 was
applied.

Before analysis, the sample gas passes through a CO2 scrubber (Ascarite)
and a water trap.

*Issue:*
When I measure samples with a natural isotopic composition, the spectral
fits for both δ15Nα and δ15Nβ are reasonably good (see attached figure).
However, when I measure my 15N-enriched samples, the fitted spectrum
deviates noticeably from the measured absorption spectrum (see figure). [...]

Re: two different topics: 1.Anti-vibration pads. 2.Regulator/gas station

Brett Kuyper — 2026-06-04T09:14:18+02:00

Hi Julia,

1. Our Delta V is still on it's wheels and happy. The laboratory does have an antivibration insert built into the floor. We were fortunate that we had the option to build up the physical space before the IRMS got moved in. There are two exposed bolts to hold the IRMS in place, these were never put down and suspect that they transmit any floor vibrations. [...]

Re: two different topics: 1.Anti-vibration pads. 2.Regulator/gas station

Robert Van Hale — 2026-06-03T23:13:45+00:00

Dear Julia,
We use what the hardware store calls “piano cups” under the wind-down IRMS feet – those little rubber cups that prevent the piano from crushing the carpet. Being a Pacific rim country, I should really add seismic restraints too – we’re required by regulation to have them on domestic hot water cylinders after all. [...]

Re: two different topics: 1.Anti-vibration pads. 2.Regulator/gas station

Veith Becker — 2026-06-03T20:48:42+00:00

Hi Julia, our Thermo IRMS all rest on adjustable threaded bolts that look like they are part of the instrument. For our 253, tapered plastic feet are attached to the bolts, which also appear to be stock. All our Delta V plus' only have bare bolts and those are resting on what, somewhat fittingly, looks like hockey pucks. I doubt those came with the instrument, but who knows. Either way, they held up well for over a decade. As for the purge valve in the carrier line, we patched a Swagelok T into the carrier gas line downstream of the [...]

Re: two different topics: 1.Anti-vibration pads. 2.Regulator/gas station

Jim Palandri — 2026-06-03T10:09:54-07:00

Hi Julia,

I never thought about it until now. The Horizon has four ~8 cm diameter
screw type leveling feet with thick rubber pads. All part of the
instrument. Meanwhile the 253 has a metal frame that rests directly on
the floor. And it was designed that way.

Our helium regulators have a check valve that will maintain pressure for
longer than it takes to move the connector to a full tank, but a sip of
air is unavoidable. [...]

Re: Use of a H2 generator

Alexandre Zahariev-CNRS — 2026-06-03T16:18:21+02:00

Hi, Christian

1I also had some issues last year with my hydrogen.
The cylinder was from Air Liquide, with a delta of around -800 per mill.
I used a hydrogen generator to test it out.
Similarly, I observed a delta per mill close to -800. But this can be
adjusted by adding deuterated water to the tank to achieve the desired
enrichment.
However, since production isn’t constant, I noticed a very strong drift
over 24 hours during my experiments. Therefore, it is not compatible
with my TC-EA-conflow3 and Delta V Plus system.
After some research on Isogeochem website, I found [...]

Use of a H2 generator

Christian Alexander Schöpke — 2026-06-03T11:41:58+00:00

IFE Public

Dear colleagues,

Do any of you have experience using a hydrogen generator (electrolysis-based) for production of the working/"reference" gas for hydrogen IRMS work? In particular, how rapidly does the produced H2 change its isotopic composition and is it stable enough for use during one analytical sequence or would we expect drift from sample to sample? Using H2 in our lab is becoming more and more difficult due to increasingly expensive HSE regulations, and switching to a hydrogen generator would solve many of the problems related to high pressure H2. I would be grateful to hear if anyone has [...]

two different topics: 1.Anti-vibration pads. 2.Regulator/gas station

Julia Valverde — 2026-06-03T02:57:20-04:00

Hi everyone,

I need help with the following two topics:

- Our IRMS is currently mounted on wheels, and the engineer who came to carry out preventive maintenance told me that this wasn’t ideal. He recommended that I replace the wheels with the IRMS’s feet and add some anti-vibration pads.
Does anyone have these and could tell me where to buy them?

- I also need information about a gas regulator or a regulator station with a purge valve, to remove the air that enters when replacing empty cylinders with new ones, avoiding getting air in your line.

I would appreciate any information you can provide.

Thanks and best wishes,
Julia

Open position: Postdoc in isotope biogeochemistry

Eliza Harris — 2026-06-03T06:09:48+00:00

Dear ISOGEOCHEMers,

We are looking for a postdoc in the METHIR project: https://jobs.unibe.ch/job-vacancies/postdoc-in-isotope-biogeochemistry/8a585c0d-3c72-4bf1-80f5-be921f4e9ec7

The project: Isotope ratio measurements are a key part of our efforts to understand sources and sinks of the major greenhouse gases CO2, CH4 and N2O. Harmonised and standardised field calibration and measurement methods are required to support isotopic measurements in networks such as the Integrated Carbon Observation System (ICOS). The METHIR project is a major European effort aimed at improving field isotope ratio measurements harmonisation and calibration, with direct linkages to current measurement networks. [...]

AW: [ISOGEOCHEM] AW: [ISOGEOCHEM] 4-Port Silflow Alternative?

Dyckmans, Jens — 2026-06-02T14:51:38+00:00

Jack’s approach of course, sorry.
Seth, the T-piece set up does not change the oxidation capabilities (pre-oxidation, seed-oxidation) at all.

Best,
Jens

Von: Stable Isotope Geochemistry <ISOGEOCHEM@list.uvm.edu> Im Auftrag von Seth Newsome
Gesendet: Dienstag, 2. Juni 2026 15:10
An: ISOGEOCHEM@LIST.UVM.EDU
Betreff: Re: [ISOGEOCHEM] AW: [ISOGEOCHEM] 4-Port Silflow Alternative?

Hi All…

Thanks for all of the feedback, schematics, and parts numbers… I have a question for those of you using a “T” or 3-port setup: does this impact your ability to do pre-oxidation or other (longer) oxidation procedures? Looking closely at the plumbing suggests to me that it doesn’t but I [...]

two different topics: 1.Anti-vibration pads. 2.Regulator/gas station

Julia Valverde — 2026-06-02T10:14:56-04:00

Re: AW: [ISOGEOCHEM] 4-Port Silflow Alternative?

Jack Hutchings — 2026-06-02T08:52:12-05:00

Hi all,

I didn't realize so many people also did the 3-port modification! I
originally got the idea from Elementar's GC-IRMS design and later noticed
that Thermo's Isolink II C Option (having one a combustion reactor) is
essentially identical to what we all describe.

For the unattached reactor, I do slide it partially out of the GC oven (as
far as a closed Isolink door will allow) to reduce the thermal 'wear' of
unnecessary GC heat cycles. [...]

Re: AW: [ISOGEOCHEM] 4-Port Silflow Alternative?

Seth Newsome — 2026-06-02T13:10:00+00:00

Hi All…

Thanks for all of the feedback, schematics, and parts numbers… I have a question for those of you using a “T” or 3-port setup: does this impact your ability to do pre-oxidation or other (longer) oxidation procedures? Looking closely at the plumbing suggests to me that it doesn’t but I don’t have any experience with using a 3-port setup… [...]

AW: [ISOGEOCHEM] 4-Port Silflow Alternative?

Dyckmans, Jens — 2026-06-02T12:45:53+00:00

Hi everyone,

Similar to Seth’s approach (and maybe to answer Florian’s question) we replaced the 4port after the reactors and the setup (MCD or siltite or whatever) before the reactors (inside the oven) by two valco T-pieces. We do not use Thermo’s welded reactors mainly for financial reasons and to switch reactors we just open the valco connections on both ends of one reactor and re-attach at the other.
In this setup, the 4port is not part of the gas way – this makes troubleshooting much easier. [...]

AW: [ISOGEOCHEM] 4-Port Silflow Alternative?

Rubach, Florian — 2026-06-02T08:19:37+00:00

Hi Jack,

I am definitely interested in more details on your alternative setup. Do you just leave the ends of the unused reactor open for doing oxidations / Methane conditionings? I have a residual worry about not sending clean enough Helium towards the instrument while the 4 port valve is in the “wrong” position during those procedures. [...]

Re: [EXTERN] [ISOGEOCHEM] 4-Port Silflow Alternative?

Daniel Nelson — 2026-06-01T19:47:51+00:00

We use a valco 3-way union with valcon polyimide ferrules and leave the unused reactor disconnected. It works in our case because we don’t switch between modes all that often.
Dan

On 1 Jun 2026, at 21:15, Natalie Wallsgrove <nw@HAWAII.EDU> wrote:

We just use a valco 4-way union and it works great (after the initial annoyance of leak resolution with the first few oven ramps). Natalie [...]

Re: 4-Port Silflow Alternative?

Matthew Rogers - NOAA Federal — 2026-06-01T11:31:44-08:00

I've also been using a Valco union instead of the MCD. However, I use a
three-way union and I have my facilities folks machine down the big bump /
knob on the union so that it doesn't have as much thermal mass. And they
are waaaaay cheaper. I have found no changes in separation /
resolution with this setup and the connections are far easier to make. It
works with the metal capillary on the stock Thermo reactors as well. [...]

Re: 4-Port Silflow Alternative?

Natalie Wallsgrove — 2026-06-01T09:15:50-10:00

Full message available at: Re: 4-Port Silflow Alternative?

Re: 4-Port Silflow Alternative?

Matheus Carvalho — 2026-06-02T05:07:25+10:00

Hi Seth, I have good experience with GC press fit connectors, they are easy
to use and leak free. There are Y shaped ones that used in series might
allow the substitution of a 4 way manifold. Just an idea. Regards,

Matheus C. Carvalho
Southern Cross University, Australia
Editor for HardwareX (Elsevier)

*Improved open source autosampler for microbalances
<https://www.researchgate.net/publication/370564297_Automated_weighing_in_the_stable_isotope_lab_when_less_is_more>* [...]

Re: 4-Port Silflow Alternative?

Jack Hutchings — 2026-06-01T13:26:05-05:00

Hi Seth,

We eventually eliminated the 4-port MCD in favor of a better capillary
solution (Agilent's CFT line) as well as 'dumbing down' the Isolink II to
simplify the flowpath. To do this, we swapped the 4-port MCD for a 3-way
CFT tee (Agilent #G3184-60065) on the GC side and, on the external side,
bypass the 4-port switching valve for a 3-way Valco tee. To swap between
HTC and Combustion modes, the connections are manually swapped. With CFT
connections, a ferrule is permanently swaged onto capillary but can be
connected/disconnected multiple times. This makes the manual swap simple
and is [...]

4-Port Silflow Alternative?

Seth Newsome — 2026-06-01T17:02:29+00:00

Hi All…

Hope all is well… I've been loyally using SGE/Trajan Silflow (MCD) on our GCC-equipped instruments for the past dozen years… Overall, they are reliable but don’t last long when routinely running AA derivatives from plants, fungi, and algae… In addition, they now cost ~$750 USD, a ~40% increase in price in the past few years… [...]

TC/EA GC oven not reaching temperature

li HUANG — 2026-06-01T12:34:02-04:00

Hello friends,

We have a TC/EA system and recently the GC oven for the first time is not
behaving. The temperature stopped at 160 C when the set point was at 300C
intended for quick baking.

The resistance is at 200 hm , very similar reading compared to the other
newer TC/EA we have in the lab. [...]

book

Bojar Ana-Voica — 2026-05-29T12:23:09+00:00

Dear all,

I am selling several volumes of the Handbook of Stable Isotope Analytical Techniques, Volume 1 and Volume 2, by Pier A. de Groot.

If you are interested, please write to me directly on: ana-voica.bojar@plus.ac.at

Best regards,

Ana-Voica Bojar

2026 Organic Geochemistry Gordon Research Conference and Seminar - Application deadline on July 5

Julio Sepúlveda — 2026-05-29T05:25:21+00:00

Dear colleagues,

This is a friendly reminder that applications for the 2026 Organic Geochemistry Gordon Research Conference (GRC; August 2-7) will be accepted until July 5, 2026. Please apply and register early, as this meeting typically reaches capacity before the deadline.
https://www.grc.org/organic-geochemistry-conference/2026/

Applications from first-time GRC attendees submitted before June 15 will be considered for the Carl Storm Opportunity Fellowship, which provides full registration support. [...]

opening postdoc position at CRPG (Lorraine University, France) - mantle noble gas analysis by IRMS

David Bekaert — 2026-05-28T13:57:26+02:00

Hello everyone,

I hope this email finds you well. We have a postdoc position opening at the University of Lorraine (CRPG, Nancy) on mantle-derived noble gas analysis by IRMS, as part of a new project funded by the French government ( [ https://pepr-origins.fr/projet/primordial/ | https://pepr-origins.fr/projet/primordial/ ] ). The project will include analytical developments, field campaigns, and noble gas analyses from hydrothermal and volcanic regions to characterize the compositions of various mantle reservoirs and develop new geochemical tools for monitoring volcanic activity. Please find below more details about the available position and please forward this on to anyone who you think [...]

FW: Ph.D. position at ETH Zurich <--> Doctoral position in plant metabolism and stable isotope biology (H-Shifts)

Werner Roland Anton — 2026-05-28T10:53:44+00:00

Dear isotope community,

<Please do not reply via ISOGEOCHEM list.>
Please circulate the following job posting to potential applicants.
Apologies for cross-posting

Doctoral position in plant metabolism and stable isotope biology (H-Shifts)
https://jobs.ethz.ch/job/view/JOPG_ethz_TGK2F1mbvhUN2rbFCZ
Project description available:
https://gl.ethz.ch/research/pepb/hshifts.html
We look forward to receiving your online application by 1 July 2026 with the following documents:
Letter of motivation
CV
Bachelor's and Master's certificates with complete transcripts
Contact information of 1-2 referees
Please note that we exclusively accept applications submitted through our online application portal. Applications via email or postal services will not be considered.
https://emea2.softfactors.com/job-opening/rgum-TGK2F1mbvhUN2rbFCZ#!/?lang=en
The desired starting date is no later [...]

Transport of a Thermo Delta V

Felix Antritter — 2026-05-27T06:49:53+00:00

Hello dear Isogeochemists,

If someone has insights how to transport a Thermo Delta V I'd be very pleased to gather this knowledge. Our lab has the opportunity to get a used one but the transport is on us. I'm familiar how to move a MAT 253 by removing the magnet and so on but I've never touched a DeltaV. I know that everything is smushed into the detector's box but that's all.
So I someone can help us out here I'd be very grateful. [...]

Query regarding SPM sampling volume for CSIA of saturated fatty acids in estuarine environments

Chen Hongguang — 2026-05-27T02:51:48+00:00

Dear ISOGEOCHEM community,
Apologies for reaching out with another question, but I would greatly appreciate your collective insights on a sampling dilemma.
I am currently planning a sampling campaign in an estuarine area to collect Suspended Particulate Matter (SPM) for compound-specific isotope analysis (CSIA) of saturated fatty acids (C16:0 to C28:0).
In much of the literature I’ve reviewed, the standard approach often involves filtering large volumes of water (100�C900 L) using 150 mm GF/F filters (Terrestrial Biomolecular Burial Efficiencies on Continental Margins, https://doi.org/10.1029/2019JG005520), and then taking a subsample (e.g., ~5g, similar to sediment samples) for lipid extraction. Due to strict [...]

Re: Thermo EA-Isolink 'not ready' issue

Peter R — 2026-05-26T20:42:16-04:00

Hi Susie,

I had this happen recently to two different Thermo flash EA-IRMSs. Funny timing. One had an issue reaching the reference flow setting of 70ml/min. It would get stuck around 65 or so. Changed the setting to 60 ml/min and the "not ready" went away. The other had an HTC reactor temp issue where it would fluctuate very minorly, so much so that if you weren't staring at it for 10 minutes straight you wouldn't notice. Turned that reactor off and the "not ready" issue went away. Not exactly a fix... more like a band-aid. [...]

Re: Thermo EA-Isolink 'not ready' issue

Hill, Brett (AAFC/AAC) — 2026-05-26T23:02:48+00:00

Unclassified / Non classifié

Hi Susie,

I had similar trouble with the EFC-t module on our Thermo Flash 2000 ten years ago. I was told I would have to order a complete module, which I did (cost was over 3600 CAD at the time). It was going to take weeks to arrive, so I opened it up, found a part number on the little plastic flow sensors, and ordered two of them online from Mouser Electronics (171 CAD each). They arrived right away and swapping one of the sensors fixed the problem. I haven't had any problems with the EFC [...]

Thermo EA-Isolink 'not ready' issue

Susan Carter — 2026-05-26T15:47:23-04:00

One morning last week when I started running our EA-irMS (Thermo Flash EA Isolink-Conflo IV-Delta V Plus), the CO2 peak was about 40 seconds late on the first two standards. On subsequent standards it started giving me “waiting for EA” delays. I was able to force it to go to “ready” a few times by adjusting the reactor temps or He pressure or power cycling the EA, but it never worked properly, and it may just be coincidence that it recovered while I was twiddling knobs. After the first few attempts it never went back to “ready.” Restarting the computer [...]

Re: Low d18O carbonate standard

Matheus Carvalho — 2026-05-26T05:39:42+10:00

Not in the range, but close:

https://analytical-reference-materials.iaea.org/iaea-co-8-2

Matheus C. Carvalho
Southern Cross University, Australia
Editor for HardwareX (Elsevier)

*Improved open source autosampler for microbalances
<https://www.researchgate.net/publication/370564297_Automated_weighing_in_the_stable_isotope_lab_when_less_is_more>*

Book: Practical Laboratory Automation Made Easy with AutoIt
<http://bit.ly/3x19AXy>

On Mon, May 25, 2026 at 9:08 PM Tim Pollard <
00001133ef6d9949-dmarc-request@list.uvm.edu> wrote:

> Hi All,
>
> I am analyzing some sub-glacial carbonates from Antarctica that have very
> low d18O values (-30 to -40 ‰, VPDB), and sit well outside the range of the
> carbonate reference materials that we normally run. I was just wondering if
> anyone is aware of a well calibrated [...]

2026 Earth Science Women's Network Leadership Roles Recruitment

Earth Science Women's Network Professional Development and Networking Committee — 2026-05-25T20:19:32+01:00

*[Deadline extended to Wednesday May 27th]*
Dear isogeochem community,

*Earth Science Women's Network (ESWN) Leadership & Volunteer Recruitment
2026*
ESWN is thrilled to announce that we are recruiting for the newest leaders
of our organization.

*ESWN Associate Board of Directors*
ESWN’s Associate Board of Directors is composed of co-chairs of four
committees that are critical to the success of our organization. For
positions starting July 1, 2026 we are accepting applications through May
27, 2026 for: [...]

Re: Low d18O carbonate standard

Marcos Lemes — 2026-05-25T09:12:08-05:00

Hi Tim,

You may get from IAEA the standard Light Antarctic Precipitation (SLAP) with d18O -55.5 and d2H -428.0.

Cheers,

Marcos

> On May 25, 2026, at 12:53 AM, Tim Pollard <00001133ef6d9949-dmarc-request@list.uvm.edu> wrote:
>
> Hi All,
>
> I am analyzing some sub-glacial carbonates from Antarctica that have very low d18O values (-30 to -40 ‰, VPDB), and sit well outside the range of the carbonate reference materials that we normally run. I was just wondering if anyone is aware of a well calibrated carbonate standard that has a similarly low d18O?
>
> Cheers,
> Tim

PVC samples on EA/IRMS

Lukas Kohl — 2026-05-25T11:02:00+03:00

Hi ISOGEOCHEM,

We have a researcher who asked us if we can determine 13C in a small number
(3) of polyvinylchloride (PVC) samples by EA/IRMS. Does one of you
have experience with running such high chlorine samples? Can we do this
without destroying our instruments, do we need to take any special
precautions?

thanks
Lukas

Low d18O carbonate standard

Tim Pollard — 2026-05-25T01:53:47-04:00

Hi All,

I am analyzing some sub-glacial carbonates from Antarctica that have very low d18O values (-30 to -40 ‰, VPDB), and sit well outside the range of the carbonate reference materials that we normally run. I was just wondering if anyone is aware of a well calibrated carbonate standard that has a similarly low d18O? [...]

Re: Nuclide mass spectrometers

Mix, Alan — 2026-05-24T03:46:37+00:00

Hah! Hey Michael, I learned on that same Lamont Nuclide in 1978. Same mercury columns, same Toeppler pumps, same glass flight tube, same paper strip-chart recorder and ruler to draw pencil lines and "measure" ratio offsets. Great learning experience when you can see all the warts.

That was the year we managed to get the data integration on the new Micromass to work on an HP calculator (the rest was all manual of course) and I think that was pretty much the end of that particular Nuclide - Jim White may have run some things about then too. He and [...]

Re: Nuclide mass spectrometers

Michael Bender — 2026-05-24T00:34:11+00:00

I too started out on a Nuclide. In the summer of 1964, as an undergraduate, I participated in a program at Lamont to introduce potential grad students to geochemistry. I worked with Bill Sackett, analyzing a suite of POC samples, taken across the Southern Ocean, to search for a temperature dependence of discrimination. My experience was similar to that described by other people in this thread: Toeppler pumps for combusting CO2, mercury pistons for balancing sample and reference pressures, manual switching of sample and reference, calculating pCO2 by drawing lines on graph paper… [...]

Re: Nuclide mass spectrometers

Grossman, Ethan L — 2026-05-23T22:12:43+00:00

All:

Yes, this brings back memories of challenging times. Tad Oba and Nobu Niitsuma, visiting scientists at USC, modified our Nuclide 6-60, epoxying the capillary into the glass piston so we could bring the mercury column up to a very small volume, allowing me to analyze very small samples (even single deep-sea benthic forams) in the late 1970s. It also meant that I could not go anywhere else to run my samples and had to keep the instrument running. Larry Miller and I did automate the instrument so that we did not have to manually switch the changeover valves every [...]

Re: AW: [ISOGEOCHEM] DeltaV/Isodat communication with external valves

Jason Visser — 2026-05-22T15:23:58-05:00

Just a quick follow up to say that you both were correct. I hooked up the
relay today and it worked perfectly.

Thanks!

On Thu, May 21, 2026 at 11:14 AM Jason Visser <jasonvisser@gmail.com> wrote:

> Thanks for the quick replies, Rob and Florian!
>
> I'll give it a go tomorrow. The relay just arrived, but I won't have time
> to test it until then.
>
> I'll let y'all know how it goes.
>
> Best,
> Jason
>
> On Thu, May 21, 2026 at 6:06 AM Rubach, Florian <
> 00000d9fb66b1fb2-dmarc-request@list.uvm.edu> wrote:
>
>> Hey Jason,
>>
[...]

Opening: Manager of the Ján Veizer Stable Isotope Laboratory (permanent)

Leonard Wassenaar — 2026-05-21T12:47:18-04:00

Seems the link I sent before was for internal staff - argh. Here is the
external link to the job posting:

https://uottawa.wd3.myworkdayjobs.com/en-US/uOttawa_External_Career_Site/job/Ottawa-ON/Manager--Isotope-Laboratory_JR34696

Len

Re: AW: [ISOGEOCHEM] DeltaV/Isodat communication with external valves

Jason Visser — 2026-05-21T11:14:46-05:00

Thanks for the quick replies, Rob and Florian!

I'll give it a go tomorrow. The relay just arrived, but I won't have time
to test it until then.

I'll let y'all know how it goes.

Best,
Jason

On Thu, May 21, 2026 at 6:06 AM Rubach, Florian <
00000d9fb66b1fb2-dmarc-request@list.uvm.edu> wrote:

> Hey Jason,
>
> could it be that the voltage is essentially floating until you load the
> pin, i.e. the voltage tries to actuate the relay?
>
> Florian
>
> Dr. Florian Rubach
> Abteilung Klimageochemie
> Max-Planck-Institut für Chemie
>
> Hahn-Meitner-Weg 1
> 55128 Mainz
> [...]

Opening: Manager of the Ján Veizer Stable Isotope Laboratory (permanent)

Leonard Wassenaar — 2026-05-21T08:32:36-04:00

Dear Colleagues

We are seeking a full-time permanent Manager for the Ján Veizer Stable
Isotope Laboratory in the Department of Earth and Environmental Sciences at
the University of Ottawa. This lab supports a broad range of environmental,
hydrological, ecological and geochemical isotope applications and operates
multiple Thermo IRMS platforms (Delta V+ / Delta Q), GasBench, EA-IRMS,
GC-C-pyr, TOC and Picarro and LGR aser isotope systems within a larger
national geochemistry and AMS research facility. [...]

Re: Vial cap material suitable for long-term CaCO3 storage ?

Schimmelmann, Arndt — 2026-05-21T11:23:06+00:00

Hello Mathieu,
I favor sealing samples in pre-annealed glass ampoules for exclusion of all and any chemical agents during long-term storage. I place a small cap of pre-annealed aluminum foil on top of the filled ampoule, pierce the cap with a syringe needle, feed dry argon through the needle into the headspace above the sample for exclusion of air, remove the needle, and immediately seal the neck of the ampoule just below the aluminum cap with the flame of a small glass blowing torch.
Cheers,
Arndt Schimmelmann

AW: [ISOGEOCHEM] DeltaV/Isodat communication with external valves

Rubach, Florian — 2026-05-21T06:34:09+00:00

Hey Jason,

could it be that the voltage is essentially floating until you load the pin, i.e. the voltage tries to actuate the relay?

Florian

Dr. Florian Rubach
Abteilung Klimageochemie
Max-Planck-Institut für Chemie

Hahn-Meitner-Weg 1
55128 Mainz
Tel: +49 6131 305 4128

-----Ursprüngliche Nachricht-----
Von: Stable Isotope Geochemistry <ISOGEOCHEM@list.uvm.edu> Im Auftrag von Jason Visser
Gesendet: Mittwoch, 20. Mai 2026 17:16
An: ISOGEOCHEM@LIST.UVM.EDU
Betreff: Re: [ISOGEOCHEM] DeltaV/Isodat communication with external valves [...]

Re: DeltaV/Isodat communication with external valves

Robert Van Hale — 2026-05-21T00:12:00+00:00

Hi Jason,
The apparent failure for the voltage to change at your output pins is a trap for us all. It seems that the valve control circuitry monitors the current draw and will not change state unless the relay/actuator/whatever load is physically connected. Using a voltmeter alone (with very high input resistance) will not register as a load. However your account of a small voltage change rings a bell with me.
Hoping I'm on the right track with this,
Rob [...]

Re: Vial cap material suitable for long-term CaCO3 storage ?

Robert Van Hale — 2026-05-21T00:00:44+00:00

Hi Mathieu,
I favour butyl rubber over any silicone or Teflon-based polymers for it's having the lowest gas solubilities and so presumably lowest permeabilities. Silicones in particular have high perfusivity and gas solubility ( used for membrane-inlet MS after all ).
If concerned about volatiles in your septum perhaps treatment in a vacuum oven would obviate that concern - as used to clean GC septa.
I had quite a hunt to find crimp seals of butyl rubber for 2 ml GC vials, but di get them in the end.
All the best
Rob [...]

Vial cap material suitable for long-term CaCO3 storage ?

Mathieu Daëron — 2026-05-20T17:32:52+02:00

Hi all,

Tapping into the collective wisdom:

What screw-on cap material would you recommend for a borosilicate glass vial intended to store calcium carbonate reference materials over a decade or longer? The usual suspects seem to be PP, PTFE, and silicon seals. I'm mostly worried about the cap material degassing volatile species that may react with CaCO3 (unlikely?) and/or interfere with high-precision IRMS [1]. Each vial will be vacuum-sealed in plastic, so water permeability of the cap is not a big concern, but please let me know if you have hard evidence that vacuum-seal plastics (e.g., used for preserving food) [...]

Re: DeltaV/Isodat communication with external valves

Jason Visser — 2026-05-20T11:15:31-04:00

Thanks Matheus and all others that have offered help and resources, it's greatly appreciated. AutoIt seems quite interesting and I might make use of it in the future, but for now I think I've got Isodat and our DeltaV doing what I need.

I am observing something that I'm wondering if anyone can offer some insight into: we have 2 DeltaV Plus instruments. Nearly identical setups. I've setup external valve control through the PnM interface in Configurator identically on both. If I monitor the voltage across the pins coming out of the PnM, on one IRMS it switches between 0V [...]

Re: DeltaV/Isodat communication with external valves

Matheus Carvalho — 2026-05-20T17:59:59+10:00

Hi, I only saw this now, as my email classified this message as spam...
I believe you can use AutoIt to do what you want, if you know the commands
that you can use to control the valve using a computer. It may be easier
than doing all the research you need to do the "proper" way. Contact me off
the list and we can go from there, if you want.
Regards, [...]

Re: valco valve actuator O-ring replacement

Verheyden-Gillikin, Anouk — 2026-05-19T10:52:23-04:00

Awesome,
thank you so much!
Anouk

Prof. Anouk Verheyden

Senior Lecturer and Stable Isotope Laboratory Manager

Union College
Department of Geosciences
807 Union St.
Schenectady, NY 12308

Office phone: (518) 388-8754
Lab phone: (518) 388-8741

email: verheyda@union.edu
web: http://minerva.union.edu/verheyda/research.html
Lab: http://minerva.union.edu/gillikid/lab.htm

On Mon, May 18, 2026 at 5:25 PM Poláková Ljubov <ljubov.polakova@bc.cas.cz>
wrote:

> Dear Anouk,
> To lift up the GB is really the only way to remove the actuator. Moreover,
> you need another pair of hands to hold the actuator inside the GB while
> detaching it.
> During disassembly of the actuator, *follow the original position of [...]

Deadline extended 22 June: Call for abstracts in session "Forest Ecophysiology, Genetics and Molecular Biology" IECF2026 14-16th September 2026

Juan Pedro Ferrio — 2026-05-19T09:14:26+02:00

Dear all,

Just a reminder that you are still on time to submit your abstract to
the 5th International Electronic Conference on Forests, deadline has
been extended till 22nd June.

https://sciforum.net/event/IECF2026?section=#session4216

Best regards,

Juan Pedro Ferrio

El 14/03/2026 a las 10:20, Juan Pedro Ferrio escribió:
> Dear colleagues,
>
> Sorry for crossposting.
>
> I would like to highlight the online session "S6. Forest
> Ecophysiology, Genetics and Molecular Biology",
> within the "5th International Electronic Conference on Forests" (
> https://sciforum.net/event/IECF2026?section=#session4216 ).
>
> The conference is fully online, and is scheduled for 14th-16th
> September 2026 CEST.
[...]

Re: valco valve actuator O-ring replacement

Poláková Ljubov — 2026-05-18T21:20:26+00:00

Dear Anouk,
To lift up the GB is really the only way to remove the actuator. Moreover, you need another pair of hands to hold the actuator inside the GB while detaching it.
During disassembly of the actuator, follow the original position of all the parts very carefully and follow the instructions. It could be sufficient. [...]

valco valve actuator O-ring replacement

Verheyden-Gillikin, Anouk — 2026-05-18T16:15:03-04:00

Dear isogeochem,

I need to replace the O-ring on the air actuator of the valco valve on a GB
II. From the technical notes on the vici website, it seems I need to access
three screws on the bottom part of the actuator. I don't see a way on how
to detach the actuator from the inside of the GB and the only thing I can
think of is to lift the GB and hope there is a way to detach it from the
bottom. However, before I try this, can someone confirm that I actually
have to lift up [...]

Postdoctoral Fellow @ UTSA

SAUGATA DATTA — 2026-05-15T00:42:58-04:00

We seek an enthusiastic and versatile scientist in the fields of geosciences and stable isotope geochemistry who will contribute to our growing research program focused on the detection and characterization of stable isotopes in environmental matrices, with strong familiarity in isotope ratio mass spectrometry. The successful applicant will ideally conduct research in the broad area of low-temperature stable isotope geochemistry, focusing on the occurrence, fate, and transport of organic matter and C-O-H-N-S isotopes in soils, sediments, and water systems. Knowledge and hands-on experience with advanced instrumentation, including operation and troubleshooting of the Delta Q Isotope Ratio Mass Spectrometer, are highly [...]

Re: Eurovector question

Simon R Poulson — 2026-05-14T16:23:00+00:00

Linda,

It sounds to me that you might have a partial blockage with a piece of particulate in one of the solenoids of the EPCs or EFM?

Good luck!

Cheers,
Simon

*****

Simon Poulson

Research Professor

Dept. Geological Sciences & Engineering MS-172

University of Nevada-Reno

1664 N. Virginia St.

Reno, NV 89557-0138 USA

(775) 784-1104

Fax: (775) 784-1833

poulson@unr.edu<mailto:poulson@unr.edu>

*****

From: Stable Isotope Geochemistry <ISOGEOCHEM@list.uvm.edu> on behalf of Linda Godfrey <00000be4a8cd5acd-dmarc-request@list.uvm.edu>
Date: Thursday, May 14, 2026 at 7:17 AM
To: ISOGEOCHEM@LIST.UVM.EDU <ISOGEOCHEM@list.uvm.edu>
Subject: Eurovector question [...]

Eurovector question

Linda Godfrey — 2026-05-14T13:56:26+00:00

Good morning -

I have a Eurovector which I had turned off from lack of use. I then turned it back on (not without some issue), but have found that the carrier pressure needed to get to the same, roughly 100mL/min (excuse me if I got the units wrong) carrier flow, is very much higher than it was before I turned it off. I was looking throug hte log, and it seems that there has been a gradual increase in the carrier pressure since we got the instrument back in the 2000's (it was double (100 kPa) last time it [...]

2026 Earth Science Women's Network Leadership Roles Recruitment

Earth Science Women's Network Professional Development and Networking Committee — 2026-05-14T12:59:25+01:00

Dear isogeochem community,

*Earth Science Women's Network (ESWN) Leadership & Volunteer Recruitment
2026*
ESWN is thrilled to announce that we are recruiting for the newest leaders
of our organization.

*ESWN Associate Board of Directors*
ESWN’s Associate Board of Directors is composed of co-chairs of four
committees that are critical to the success of our organization. For
positions starting July 1, 2026 we are accepting applications through May
25, 2026 for: [...]

Re: d13C in methanol, BF3 and BSTFA?

Charlotte Slaymark — 2026-05-14T11:47:52+00:00

Hi Daniel,

I have carried out corrections for this but with an alternative approach at Glasgow using GC-IRMS- it was very easy to do. Sebastian Naeher in NZ also has done it this way and suggested it to us.

To determine the contribution of 13C from the MeOH in the derivatising agents we run an alcohol standard e.g. try 10 mg/l palmitoleic acid- un-derivatised, on the GC IRMS - the chromatography is not good but its fine for this purpose ( you may need to adjust concentration, we run in splitless mode) and run a derivatised one and use these [...]

d13C in methanol, BF3 and BSTFA?

Daniel Carrizo Gallardo — 2026-05-14T12:01:59+02:00

Dear colleagues,

I need to analyze the d13C of some reactives that we used to derivatize
our fatty acids and alkanols.

The reactives are: pure methanol, Boron trifluoride in methanol(BF3) to
methylated the fatty acids and the 3 carbons of the BSTFA
(N,O)-Bis(trimethylsilyl)trifluoroacetamide) for the trimethyl silyl
alkanols.

My idea is to analyzed this in the elemental analyzer has a “solid”
sample, it is possible or there is any kind of pre-treatment to avoid
some impurities, etc. [...]

SIMSUG 2026

Helen Whelton — 2026-05-14T07:17:54+00:00

Dear stable isotope user,

The 17th meeting of the Stable Isotope Mass Spectrometry Users Group (SIMSUG) will take place 15th-16th June 2026 at the School of Chemistry, University of Bristol. The meeting brings together the latest developments and applications for the use of stable isotopes across a wide range of disciplines including: archaeology, food science, geoscience, health sciences, and forensics, to name but a few. [...]

Postdoctoral Researcher Job at the Karlsruhe Institute of Technology (KIT)

Kimmig, Sara Rose (AGW) — 2026-05-13T19:40:08+00:00

Dear Isogeochem community,

The Institute of Applied Geosciences (AGW) at the Karlsruhe Institute of Technology (KIT) is pleased to announce the following search for a postdoctoral researcher in the Chair of Geochemistry and Economic Geology.

At the Chair of Geochemistry and Economic Geology, we focus our research on hydrothermal ore deposits, geochemistry of geothermal systems, re-mining of mine waste, pollutant dynamics and liquid mining. We wish to develop strong and visible research in these fields. We offer this position in order to strengthen our research team in the fields above with an individual that already has initial PostDoc-experience. Our laboratory [...]

Re: [EXT] [ISOGEOCHEM] Regarding the Thermocouple sensor type of TC/EA Thermo scientific .

Zhang, Xiaoyu - (zhangxy) — 2026-05-13T16:29:19+00:00

If your TC/EA is thermo Finnigan, the Thermocouple is Thermo Fisher Scientific Bremen 1121470, and you can order through Unity Lab. Best Wishes! Xiaoyu *********************************************** Mailing Address: Xiaoyu Zhang Environmental Isotope Lab, Geosciences The University of Arizona 1040 E. Fourth Street [...]

Save the Date – Nordic Isotope Users’ Symposium (NIS) 2027

Getachew Agmuas — 2026-05-12T17:36:06+02:00

Dear colleagues,

Please save the date for the upcoming *Nordic Isotope Users’ Symposium
(NIS) 2027*, which will take place in beautiful Copenhagen from *23–27
August 2027*.

The symposium will feature a *three-day course and two-day symposium*
covering:

-

Traditional light-element isotopes
-

Metal isotopes
-

Radiocarbon
-

Triple oxygen isotopes
-

Clumped isotopes

Applications will include:

1.

Carbon and nitrogen biogeochemical cycles in the soil–plant–atmosphere
continuum
2.

Pollution, food, and forensic applications
3. [...]

Invitation to Join InSync Working Group on Modern Water Isotope Observations in Antarctica

Niels Dutrievoz — 2026-05-12T16:17:24+02:00

Dear colleagues,

We would like to invite you to join a new Working Group within the Antarctica InSync initiative focused on modern-day stable water isotope observations in Antarctica.

This cross-theme working group will be affiliated with Themes II, VI, VII and more, depending on the members. The working group aims to address the need for a coordinated observational network necessary to trace the origins and transport pathways of moisture reaching both the Antarctic coast and the interior. Stable water isotope measurements provide a powerful tracer of diabatic processes, enabling links between key local physical processes and the large-scale atmospheric circulation. [...]

Re: Regarding the Thermocouple sensor type of TC/EA Thermo scientific .

Sivesh Ahirwar — 2026-05-12T05:42:57+00:00

Thanks for sharing this valuable information....

Regards

SIVESH AHIRWAR

Get Outlook for Android<https://aka.ms/AAb9ysg>

Small Sample Introduction Module 2 (Picarro) for sale

Flanagan, Larry — 2026-05-11T20:30:04+00:00

HI All

I have a gently used A0314 Small Sample Introduction Module 2 available for sale.

The module should be compatible with Picarro iCO2, iCH4 (G2101-i, G2121-i, G2131-i, G2132-i, G2201-i), and select iN2O instruments (G5101-i and the G5131-i), and two concentration analyzers (G2308, G2508).

If you are interested - please contact me via email (off list) at: [...]

Re: Regarding the Thermocouple sensor type of TC/EA Thermo scientific .

Jim Palandri — 2026-05-11T10:06:02-07:00

Hello Sivesh,

The table linked below shows it to be either type R or S (but with no
further info to discern between the two.) I suspect that either will
work for most applications.

https://pages.uoregon.edu/palandri/EP/Thermocouple_color_code.png

Cheers,
-Jim

On 5/11/26 05:48, Sivesh Ahirwar wrote:
> Thanks for responding me. . . I checked in TC/EA and found two wire one
> is white and 2nd is orange colour. Can you define what type this is. . .
> Thanks. Regards. . . SIVESH AHIRWAR Get Outlook for Android From:
> Srikanth Gedela <srikanth. gedela@ GMAIL. COM>
> ZjQcmQRYFpfptBannerStart
> This message originated outside the UO email ecosystem.
> Use caution [...]

Looking for a Picarro A0325 autosampler

Justin VanDeVelde — 2026-05-11T12:36:14-04:00

Hello all,
We are in search of a used Picarro A0325 autosampler. We have an older
L2140 water analyzer in need of an autosampler, it's not compatible with
the model Picarro currently sells and would need a trip back to the factory
to replace the motherboard. We're hoping to skip that step if someone has
an old A0325 we could purchase. We have a vaporizer and just need the
autosampler itself. [...]

Pyro cube

Ulrike Baranowski — 2026-05-11T13:19:50+00:00

Dear isogeochem community,
Thanks everyone with the help of pyrocube method on precisION works now like a dream!

Major issues where bake out of the CO2 trap and modifying the method that CO2 would release right at the right time.

As I have 4 interfaces on the precisION I was trying to now link the pyrocube to my older Delta V instrument via conflow 3.
Managed with help from SUERC to create a remote trigger from conflow to pyro installed the pyro software on a new computer and plugged in the USB connection directly into this computer to connect to [...]

Re: Regarding the Thermocouple sensor type of TC/EA Thermo scientific .

Sivesh Ahirwar — 2026-05-11T12:48:31+00:00

Thanks for responding me...

I checked in TC/EA and found two wire one is white and 2nd is orange colour. Can you define what type this is...

Thanks.

Regards...

SIVESH AHIRWAR

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Re: Regarding the Thermocouple sensor type of TC/EA Thermo scientific .

Srikanth Gedela — 2026-05-11T08:37:09-04:00

Hello Sivesha,

The color of the thermocouple lead wires, will tell the type of thermocouple
example if wire lead colors are White (+) and Red (-) its J type thermocouple, Yellow (+) and Red (-) its K type thermocouple.

Best
srikanth
srikanth_gedela@brown.edu

Regarding the Thermocouple sensor type of TC/EA Thermo scientific .

Sivesh Ahirwar — 2026-05-11T10:06:29+00:00

Dear all!

I would like to ask which type of thermocouple is used in the heater of the TC EA. Our thermocouple has broken, so please let me know the correct type used in this system. Any response would be appreciated.

Thank you.
Regards,

SIVESH AHIRWAR
INDIAN INSTITUTE OF SCIENCE BANGALORE

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Sulfur blank and peak tailing

Srikanth Gedela — 2026-05-07T03:39:07-04:00

Hello All,

We are experiencing a persistent sulphur blank issue with our vario ISOTOPE select configured in CNS mode. The sulphur blank is consistently around 1–2 nA peak height and could not be eliminated despite multiple blank runs and extensive troubleshooting efforts.

The following actions were already performed:

1. Installed new combustion and reduction tubes with fresh fillings
2. Cleaned the ash finger, quartz bridge thoroughly
3. Refilled the drying agent with fresh material
4. Performed multiple bake-outs of the TPD column
5. Tested with a different helium cylinder/batch
6. Replaced the TPD column with a brand-new column supplied by [...]