High-Throughput Immunomagnetic Scavenging Technique for Quantitative Analysis of Live VX Nerve Agent in Water, Hamburger, and Soil Matrixes

• Published in: Analytical chemistry (Washington) Vol. 84; no. 22; pp. 10052 - 10057
• Main Authors: Knaack, Jennifer S, Zhou, Yingtao, Abney, Carter W, Prezioso, Samantha M, Magnuson, Matthew, Evans, Ronald, Jakubowski, Edward M, Hardy, Katelyn, Johnson, Rudolph C
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 20-11-2012
• Subjects: Analytical chemistry; Chemical Fractionation - methods; Chemical Warfare Agents - analysis; Chemical Warfare Agents - isolation & purification; Chemistry; Chromatographic methods and physical methods associated with chromatography; Chromatography; Chromatography, High Pressure Liquid; Enzymes; Exact sciences and technology; Extraction processes; Food Analysis - methods; Magnets; Microspheres; Organothiophosphorus Compounds - analysis; Organothiophosphorus Compounds - isolation & purification; Other chromatographic methods; Quality control; Soil - chemistry; Water - chemistry; Targeting; HPLC chromatography; Esterases; Accuracy; Specificity; Sample preparation; Detection limit; Standard deviation; Extraction; Quantitative analysis; Enzyme; Antibody; Sample; Ultratrace compound; Concentration; Method; Tap water; Cholinesterase; Carboxylic ester hydrolases; Soils; Sensitivity; Quality control; Hydrolases; Inhibitor; Organophosphorus compounds; Small sample; Technique
• ISSN: 0003-2700; 1520-6882
• DOI: 10.1021/ac3025224

We have developed a novel immunomagnetic scavenging technique for extracting cholinesterase inhibitors from aqueous matrixes using biological targeting and antibody-based extraction. The technique was characterized using the organophosphorus nerve agent VX. The limit of detection for VX in high-performance liquid chromatography (HPLC)-grade water, defined as the lowest calibrator concentration, was 25 pg/mL in a small, 500 μL sample. The method was characterized over the course of 22 sample sets containing calibrators, blanks, and quality control samples. Method precision, expressed as the mean relative standard deviation, was less than 9.2% for all calibrators. Quality control sample accuracy was 102% and 100% of the mean for VX spiked into HPLC-grade water at concentrations of 2.0 and 0.25 ng/mL, respectively. This method successfully was applied to aqueous extracts from soil, hamburger, and finished tap water spiked with VX. Recovery was 65%, 81%, and 100% from these matrixes, respectively. Biologically based extractions of organophosphorus compounds represent a new technique for sample extraction that provides an increase in extraction specificity and sensitivity.