Jump to main content
Jump to site search

Issue 5, 2010
Previous Article Next Article

Screening of agrochemicals in foodstuffs using low-temperature plasma (LTP) ambient ionization mass spectrometry

Author affiliations

Abstract

Low-temperature plasma (LTP) permits direct ambient ionization and mass analysis of samples in their native environment with minimal or no prior preparation. LTP utilizes dielectric barrier discharges (DBDs) to create a low power plasma which is guided by gas flow onto the sample from which analytes are desorbed and ionized. In this study, the potential of LTP-MS for the detection of pesticide residues in food is demonstrated. Thirteen multi-class agricultural chemicals were studied (ametryn, amitraz, atrazine, buprofezin, DEET, diphenylamine, ethoxyquin, imazalil, isofenphos-methyl, isoproturon, malathion, parathion-ethyl and terbuthylazine). To evaluate the potential of the proposed approach, LTP-MS experiments were performed directly on fruit peels as well as on fruit/vegetable extracts. Most of the agrochemicals examined displayed remarkable sensitivity in the positive ion mode, giving limits of detection (LOD) for the direct measurement in the low picogram range. Tandem mass spectrometry (MS/MS) was used to confirm identification of selected pesticides by using for these experiments spiked fruit/vegetable extracts (QuEChERS, a standard sample treatment protocol) at levels as low as 1 pg, absolute, for some of the analytes. Comparisons of the data obtained by direct LTP-MS were made with the slower but more accurate conventional LC-MS/MS procedure. Herbicides spiked in aqueous solutions were detectable at LODs as low as 0.5 µg L−1 without the need for any sample preparation. The results demonstrate that ambient LTP-MS can be applied for the detection and confirmation of traces of agrochemicals in actual market-purchased produce and in natural water samples. Quantitative analysis was also performed in a few selected cases and displayed a relatively high degree of linearity over four orders of magnitude.

Graphical abstract: Screening of agrochemicals in foodstuffs using low-temperature plasma (LTP) ambient ionization mass spectrometry

Back to tab navigation

Supplementary files

Publication details

The article was received on 18 Sep 2009, accepted on 10 Dec 2009 and first published on 12 Jan 2010


Article type: Paper
DOI: 10.1039/B919493B
Citation: Analyst, 2010,135, 971-979
  •   Request permissions

    Screening of agrochemicals in foodstuffs using low-temperature plasma (LTP) ambient ionization mass spectrometry

    J. S. Wiley, J. F. García-Reyes, J. D. Harper, N. A. Charipar, Z. Ouyang and R. G. Cooks, Analyst, 2010, 135, 971
    DOI: 10.1039/B919493B

Search articles by author

Spotlight

Advertisements