Updated Methods: OPPs and OCPs now performed by EPA 625.1

Updated Methods! OPPs and OCPs now performed by EPA 625.1

To provide the most current method references for your regulatory samples, we are now performing Organochlorine and Organophosphorus Pesticides by EPA 625.1. There will be no changes in our compound lists, reporting limits (RLs), or container requirements. Because the OCP/PCB analysis requires a neutral-only extraction to overcome decomposition and chromatographic challenges (different from the full base -neutral-acid extraction for the full semi-volatiles list by EPA 625.1) the laboratory will still require separate containers for the extraction and analysis. Please contact your project manager or the client services team if you have any questions.

Here’s why we updated our method.

Historically, Caltest has performed Organophosphorus Pesticides (OPP’s) by EPA 614; and Chlorinated Pesticides (OCP’s) and PCB’s by EPA 608. In late 2019 we were approved for these analysis by EPA 625.1, per 40CFR 136.3, Table ID.  OPP’s by EPA 614 were performed using Mass Spectrometry (MS) instrumentation; and the OCP’s by EPA 608 were performed by Gas Chromatography – Electron Capture Detector (GC-ECD) and Mass spectrometry (MS) instrumentation. Our addition of the MS column eliminated the common occurrence of false positive reporting observed using the typical dual-GC column approach.

Caltest will continue to perform these analyses in a similar manner as we have historically — by maintaining the elimination of false positive detections due to better selectivity of the instrumentation technology — however, since a GC-MS method (EPA 625.1) is now EPA approved for NPDES compliance reporting of the Organophosphorus Pesticides and the Priority Pollutant OCP and PCB compounds, we will be performing/reporting these requests using EPA 625.1. Additionally, CA-ELAP has these compounds already incorporated into FOT 111 as “Semi-volatile Organic Constituents” by EPA 625.1.