My lab runs D4815 on a 7890 using Open Lab CDS and I noticed a discrepancy between our method and what is described in ASTM D4815 in regards to the sample amount. Internally, it looks like our techs measure 0.5ml of internal standard into a 10ml flask, record the mass, then fill to volume with sample and record the overall mass of sample + ISTD. … Show more
Hello, I cannot weigh in on your methodology, but here is a link to the Reference to Operation Principles guide for OpenLab CDS ChemStation: https://www.agilent.com/cs/library/usermanuals/public/CDS_CS-references.pdf The section outlining the math of the ISTD calculations begins on page 92. Please let us know if you have any questions.