Frequent Questions

For EPA Method 531.1: Sections 4.3 and 11.3.3 discuss the use of mass spectrometers for more positive identification of analytes if detected in lieu of second column confirmation and the fluorescence detector. Can the laboratory adopt the use of the MS as

No – method is based solely on post-column derivatization with fluorescence detection.  Labs can modify HPLC conditions and columns but they do not have the authority to modify the determinative part of the method.  Use of a mass spectrometer is only considered in Method 531.1 for the purpose of confirmation.  If the lab is encountering issues, they should consider switching to the updated version, EPA Method 531.2.  But Method 531.2 is also a fluorescence detection technique.

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