Life of an insert depends greatly on the type samples run and their size/weight. For glass filters the life is usually around 20-25 filters, For sediments >20mg - ~100 samples Sediments <20mg - 150 to 200 samples. Brian Jones Research Assistant Dept. of Oceanography Texas A&M University College Station Tx. 77843 (979) 845-8916 -----Original Message----- From: Stable Isotope Geochemistry [mailto:[log in to unmask]] On Behalf Of River He Sent: Sunday, September 26, 2004 4:47 PM To: [log in to unmask] Subject: Re: [ISOGEOCHEM] EA insert tubes Hello All, I'd like to know nromally how many samples you guys analyse before changing a new quartz insert. Thanks, River He ______________________________________________________________________ Post your free ad now! http://personals.yahoo.ca