Isotope Dilution GC/MS/MS Pesticide Testing

ALS Environmental offers the analysis of organochlorine pesticides by isotope dilution Gas Chromatograph/ Mass Spectroscopy/Mass Spectroscopy (GC/MS/MS), using our new Waters Quatro triple quadrapole.

It is well known that the analysis of organochlorine pesticides by traditional EPA methodologies that use Gas
Chromatographs with Electron Capture Detectors (GC/ECD) are often affected by the presence of PCB congeners (polychlorinated biphenyl congeners) and other co-extractable interferences causing false positive identification and/or over estimation. High biased results for organochlorine pesticides can lead to an overall lack of data confidence and unnecessary environmental actions.

To eliminate co-extractable and PCB congener interference, ALS Environmental has developed a unique method using isotope dilution with Large Volume Injection (LVI) and GC/MS/MS. Using standard extraction procedures combined with this analytical method, ALS Environmental is able to achieve detection levels up to 20 times lower than typically observed by ECD detection.

The triple-quad LVI/GC/MS/MS provides excellent selectivity in complex matrices by generating unique spectral fingerprints. These fingerprints provide unambiguous identification producing increased data defensibility. This enhancement is essential in further reducing co-extractable interferences. Isotopic standards increase the precision and accuracy in measuring the concentration of the pesticides. This method is applicable to water, soil/sediment and tissue matrices.

Method Detection Limits and Method Reporting Limits