Restek has reinvented sample preparation for pesticide residue analysis by LC-MS\/MS. A new workflow which enables the automation of sample cleanup has been shown to save time and money over conventional hands-on sample preparation procedures. By leveraging the power of inline sample preparation (ILSP), matrix constituents are removed from sample extracts concomitantly with analysis resulting in unprecedented increases in sample throughput.<\/p>\n\n\n\n
Recently, ILSP was put to the test with spinach matrix where chlorophyll pigments and other matrix constituents were removed from the sample extract using a UHPLC system equipped with an auxiliary pump, 6-port high pressure switching valve, and dual-directional ILSP cartridge containing bonded silica. The new procedure was evaluated as an entirely separate workflow using a simple solid-liquid extraction and as part of a cleanup strategy in conjunction with QuEChERS. Accuracy and precision experiments were conducted in spinach at two concentration levels (n=6). Of the 63 pesticides tested, 86% (0.005 mg\/kg) and 100% (0.05 mg\/kg) displayed average recoveries within 70-120% and RSD values \u226420% for the ILSP method. In addition, low to moderate matrix effects (<50%) were calculated for 95% of the analytes. Overall performance of the proposed method was found to be better or comparable to a traditional QuEChERS procedure utilizing AOAC formulated salts and dSPE sorbents, while significantly reducing the amount of pigments reaching the MS source. The ILSP workflow is a simpler procedure with fewer steps that require less time than traditional extraction and cleanup techniques.<\/p>\n\n\n\n