A High-Throughput Diagnostic Method for Measuring Human Exposure to Organophosphorus Nerve Agents

• Published in: Analytical chemistry (Washington) Vol. 84; no. 21; pp. 9470 - 9477
• Main Authors: Knaack, Jennifer S, Zhou, Yingtao, Abney, Carter W, Jacob, Justin T, Prezioso, Samantha M, Hardy, Katelyn, Lemire, Sharon W, Thomas, Jerry, Johnson, Rudolph C
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 06-11-2012
• Subjects: Analytical chemistry; Biomarkers - metabolism; Blood Chemical Analysis - methods; Butyrylcholinesterase - metabolism; Calibration; Chemical compounds; Chemical Warfare Agents - analysis; Chemical Warfare Agents - metabolism; Chemistry; Chromatography, Liquid; Environmental Exposure - analysis; Enzymes; Exact sciences and technology; General, instrumentation; Human exposure; Humans; Magnets - chemistry; Microspheres; Organophosphorus Compounds - blood; Organophosphorus Compounds - metabolism; Peptides; Quality Control; Spectrometric and optical methods; Tandem Mass Spectrometry; Fold; Peptides; Instrumentation; Esterases; Separation method; Sample preparation; Detection limit; Ion spectrometry; Serum; Extraction; Diagnosis; Adduct; Trace analysis; Human; Automation; Enzyme; Sample; Exposure; Concentration; Cholinesterase; Carboxylic ester hydrolases; Automatic processing; Ion mobility; Quality control; Reference material; Transfer; Hydrolases; Inhibitor; Organophosphorus compounds; Application
• ISSN: 0003-2700; 1520-6882
• DOI: 10.1021/ac302301w

An automated high-throughput immunomagnetic separation (IMS) method for diagnosing exposure to the organophosphorus nerve agents (OPNAs) sarin (GB), cyclohexylsarin (GF), VX, and Russian VX (RVX) was developed to increase sample processing capacity for emergency response applications. Diagnosis of exposure to OPNAs was based on the formation of OPNA adducts to butyrylcholinesterase (BuChE). Data reported with this method represent a ratio of the agent-specific BuChE adduct concentration, relative to the total BuChE peptide concentration that provides a nonactivity measurement expressed as percent adducted. All magnetic bead transfer steps and washes were performed using instrumentation in a 96-well format allowing for simultaneous extraction of 86 clinical samples plus reference materials. Automating extractions increased sample throughput 50-fold, as compared to a previously reported manual method. The limits of detection, determined using synthetic peptides, were 1 ng/mL for unadducted BuChE and GB-, GF-, VX-, and RVX-adducted BuChE. The automated method was characterized using unexposed serum and serum pools exposed to GB, GF, VX, or RVX. Variation for the measurement of percent adducted was <12% for all characterized quality control serum pools. Twenty-six (26) serum samples from individuals asymptomatic for cholinesterase inhibitor exposure were analyzed using this method, and no background levels of OPNA exposure were observed. Unexposed BuChE serum concentrations measured using this method ranged from 2.8 μg/mL to 10.6 μg/mL, with an average concentration of 6.4 μg/mL.