Research Article: Development of quantitative screen for 1550 chemicals with GC-MS

Date Published: March 19, 2018

Publisher: Springer Berlin Heidelberg

Author(s): Alan J. Bergmann, Gary L. Points, Richard P. Scott, Glenn Wilson, Kim A. Anderson.

http://doi.org/10.1007/s00216-018-0997-7

Abstract

With hundreds of thousands of chemicals in the environment, effective monitoring requires high-throughput analytical techniques. This paper presents a quantitative screening method for 1550 chemicals based on statistical modeling of responses with identification and integration performed using deconvolution reporting software. The method was evaluated with representative environmental samples. We tested biological extracts, low-density polyethylene, and silicone passive sampling devices spiked with known concentrations of 196 representative chemicals. A multiple linear regression (R2 = 0.80) was developed with molecular weight, logP, polar surface area, and fractional ion abundance to predict chemical responses within a factor of 2.5. Linearity beyond the calibration had R2 > 0.97 for three orders of magnitude. Median limits of quantitation were estimated to be 201 pg/μL (1.9× standard deviation). The number of detected chemicals and the accuracy of quantitation were similar for environmental samples and standard solutions. To our knowledge, this is the most precise method for the largest number of semi-volatile organic chemicals lacking authentic standards. Accessible instrumentation and software make this method cost effective in quantifying a large, customizable list of chemicals. When paired with silicone wristband passive samplers, this quantitative screen will be very useful for epidemiology where binning of concentrations is common.

Partial Text

Hundreds of thousands of chemicals exist in the environment. Many chemicals are known to pose health risks and many more are yet to be evaluated. Semi-volatile organic chemicals (SVOCs) are of interest because they are often bioavailable, have potential adverse health impacts, and can be persistent in the environment. Rapid and cost-effective methods for sampling and analysis are necessary to improve our ability to monitor environmental contamination and prioritize chemicals for health research.

The MASV1500 method described here is a targeted analysis for a large number of chemicals that can be used effectively in conjunction with non-targeted methods or sample fractionation [17, 29]. Quantitation using AMDIS and a predictive model for response factor was able to quantify multiple classes of chemicals in representative samples within a factor of 2.5, better than comparable methods that have been previously reported. This method can screen for over a thousand chemicals with less analyst time than typical methods. A different deconvolution software may offer better resolution between isomers. Other software options are available for deconvolution including a component of Agilent’s Mass Hunter [30], and many open source packages. When combined with high-throughput analysis such as with passive sampling wristband work-flows, the quantitative screen described here improves efficient environmental monitoring. Overall analysis workflow would be improved through the reduction of solvents in sample processing. To that end, thermal desorption of PSDs instead of solvent extraction could increase extraction efficiency and reduce cost of analysis.

 

Source:

http://doi.org/10.1007/s00216-018-0997-7

 

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