Personally, I would not recommend using NH4Cl as a working standard.
A) ammonium chloride is hygroscopic and will, if not kept dry turn into mush. Aqueous solutions of ammonium chloride are slightly acidic so there is the risk of partial loss (decomposition) of material.
B) TC/EA and halogens do not play nice.
C) due to its hygroscopic nature as a standard for 2H analysis ammonium chloride (ditto ammonium nitrate) is as useful as a one-legged man in an arse-kicking competition. Each H in NH4+ exchanges H like the blazes and linked to that is a whopping isotopic fractionation. Been there, done it, seen it; not because I wanted to use ammonium salts as TC/EA standard but to check pitfalls of their 2H analysis in a forensic context.
If you want to create an inorganic 15N standard for N in its reduced state (for 15N by EA-IRMS) follow the IAEA's example and opt for ammonium sulphate. For use as 2H standards ammonium salts cannot / should not be used (i.m.c.o).
Prof. Dr W Meier-Augenstein, CChem, FRSC
Stable Isotope Forensics & Analytical Sciences
Robert Gordon University
School of Pharmacy and Life Sciences
T.: +44 (0)7979 742853
E.: [log in to unmask]
From: Stable Isotope Geochemistry [[log in to unmask]] On Behalf Of Ambrose, Stanley H [[log in to unmask]]
Sent: 30 March 2015 23:44
To: [log in to unmask]
Subject: [ISOGEOCHEM] Ammonium Chloride analysis on EA and TCEA
We would like to analyze NH3Cl (ammonium chloride) for use as a possible working standard on the EA and monitor of N2 peak timing on the TCEA. Does combustion at EA or TCEA temperatures generate unusual compounds that might damage the system, for example HCl?
Stanley H. Ambrose, Professor
Director, Environmental Isotope Paleobiogeochemistry Laboratory
Department of Anthropology
Department of Geology
Center For African Studies
Program in Ecology Evolution and Conservation Biology
Division of Nutritional Sciences
University of Illinois,
Urbana, IL 61801 USA
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