Updates and Improvements to PPCP Method MLA-075

SGS AXYS is a leader in the measurement of pharmaceuticals and personal care products (PPCPs) in the environment. Our methods were used as the basis for EPA Method 1694 in 2007 and these isotope-dilution LC-MS/MS PPCPs methods has since expanded to include close to 200 drugs, metabolites, hormones and personal care products. From natural and synthetic steroid hormones to analgesics, anti-depressants, X-Ray agents, antibiotics, tracers like sucralose, and ubiquitous contaminants such as bisphenols, our PPCP methods are comprehensive.

We are excited to announce some updates to our main PPCP analytical method, MLA-075 that will enhance the quality of analytical results that we provide you. Since we first developed this method in 2006/7 and it was published as EPA 1694 in Dec. 2007, there have been improvements in analytical instrumentation and in the availability of stable isotope labeled standards. Our upcoming revision of MLA-075 takes advantage of these modern developments to improve our method and its ability to handle complex sample matrices and overall data quality.

This revision of our method includes 3 of the 7 lists or groups of compounds we analyze, specifically the 2 hormones lists and List 3 (acid extractable compounds that are analyzed by negative ion electrospray (ESI NEG) MS/MS).

Improvements

• Data continuity: All targets in the lists are maintained, and sample preparation and cleanup procedures remain largely unaltered.
• Better isotope-dilution coverage: We have added 13 additional labeled standards, one for every analyte on these lists except for allyl trenbolone, which is not yet available. This results in true isotope dilution quantification and highly accurate analytical results.
• Better sensitivity: Our new instruments also provide better sensitivity resulting in lower reporting limits for key analytes (notably BPA, triclosan, ibuprofen and 2-hydroxy ibuprofen). Reporting limits are not increasing for any analytes.
• Improved positive identification: Both primary and secondary transitions will now be monitored for each compound to enhance positive identification of target analytes, and ratio criteria are being developed from the new methods. This will result in fewer flagged data points and better data quality.
• Better chromatography and capacity: Our use of U(H)PLC and modern mass spectrometers provides for sharper peaks and better separation from interferences, and our growing stable of UPLC-MS/MS provides for greatly increased capacity and throughput.
• Addition of 17 beta-Estradiol-Benzoate to the hormones lists: With the addition of this veterinary synthetic estradiol, MLA-075 now offers all the hormones in EPA Method 1698 for sterols and hormones, a GC-HRMS approach developed and validated by SGS AXYS for the EPA in 2007. This is a significant streamlining on methods as EPA 1698 (SGS AXYS method MLA-068) uses more cumbersome GC-HRMS methodology. In addition to all EPA 1698 hormone targets, MLA-075 also offers allyl trenbolone, a  progestin used in veterinary medicine.
• Hormones in tissue: Hormones residues in tissue were previously offered as a custom analysis, not fully validated. This analysis is now fully validated in tissue for all targets except allyl trenbolone and 17beta-Estradiol 3-benzoate which did not meet our stringent validation requirements at this time .

Overall, we hope you be pleased with these improvements as they are reflected in your analytical results. In the new year we will continue updating our analyses of the other compounds in this method. Please contact us if you have any questions about these method changes. Our project managers are more than happy to answer your questions.