Submitted to: Journal of American Society for Mass Spectrometry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/27/2020
Publication Date: 2/20/2021
Citation: Chakrabarty, S., Shelver, W.L., Smith, D.J. 2021. Electrospray ionization inlet tandem mass spectrometry: A hyphenated method for the sensitive determination of chemicals in animal tissues and body fluids. Journal of American Society for Mass Spectrometry. 32:14-20. https://doi.org/10.1021/jasms.9b00114.
Interpretive Summary: Liquid chromatography-mass spectrometry (LCMS) is a very powerful analytical tool used to identify and/or quantify a host of chemicals in water, foods, and environmental samples. During a typical analysis, samples are purified, then introduced onto a LCMS; it may take several minutes to analyze a single sample because chromatographic purification of sample analytes occurs prior mass spectrometric analysis. In this study, chromatographic separation was eliminated prior to sample introduction into the mass spectrometer. Further, a new ionization technique called “ESII” was used to quantify a diverse set of chemicals in complex animal matrices including urine, blood, and tissues. The new technique was remarkable in that the sensitivity for most analytes was increased relative to conventional LC-MS. Additionally, the total analysis time was reduced relative to standard techniques and less solvent was used. Thus, ESII analysis represents a potentially useful, environmentally friendly, and time saving analytical method for the analysis of chemical residues in a variety of animal matrices.
Technical Abstract: This study demonstrates the utility of electrospray ionization inlet mass spectrometry (ESII-MS/MS) for the quantitative determination of analytes in complex animal matrices without chromatographic separation. Veterinary drugs including flunixin, its metabolite 5-hydroxy flunixin, and zilpaterol, and persistent organic perfluoroalkyl compounds were determined in incurred plasma, urine and/or tissue samples. Limits of detection (LOD) of zilpaterol in kidney, liver, lung, and muscle ranged from 0.02 to 0.06 ng/g whereas the limit of quantitation (LOQ) for zilpaterol in all tissues was 0.1 ng/g. For urinary or plasma flunixin, 5-hydroxy flunixin and PFOS/PFHxS, LODs ranged from 0.1 to 0.7 ng/mL while the LOQs ranged from 0.4 – 50 ng/mL. Regression coefficients for matrix-matched standard curves were 0.993 to 0.997, 0.977 to 0.999, and 0.999 for plasma, tissues and urine, respectively. Correlations between quantitative results obtained by ESII-MS/MS and LC-MS for flunixin, 5-hydroxy flunixin and zilpaterol ranged from 0.930 to 0.985. ESII-MS/MS provided rapid, sensitive, and accurate analyses of veterinary drugs and environmental contaminants from complex matrices without chromatographic separation.