Validated HPLC-MS/MS Method To Quantify Low Levels of Domoic Acid in Plasma and Urine after Subacute Exposure

Abstract

Domoic acid (DA) is a marine neurotoxin produced by several species of Pseudo-nitzschia. DA causes severe neurological toxicity in humans and animals. To address the current analytical need to quantify low levels of DA in human and animal body fluids, a sensitive and selective high performance liquid chromatography-tandem mass spectrometry method was developed to measure DA in plasma and urine. This method was fully validated to accurately and precisely quantify DA between 0.31 and 16 ng/mL in plasma and between 7.8 and 1000 ng/mL in urine. Our group introduced the use of a novel internal standard, tetrahydrodomoic acid to control for matrix effects and other sources of variability. This validated method will be useful to assess DA concentrations in biological samples of human or animal origin after suspected DA exposure from contaminated food. It will also be applicable to sentinel programs and research studies to analyze body fluids with low levels of DA.

Effects of oral domoic acid exposure on maternal reproduction and infant birth characteristics in a preclinical nonhuman primate model

“…Dosing occurred at approximately the same time every morning (~9 AM), seven days a week. Dosing solutions were analyzed for DA content by LC-MS/MS to confirm DA concentrations (Shum et al, 2018). Females were fed Lab Diet High Protein Monkey Diet biscuits approximately 2 hours before the daily DA dosing and again approximately 5 hours after dosing.…”

“…Plasma was stored at −20°C until analysis. DA was measured using a recently developed and validated LC-MS/MS method (Shum et al, 2018). The lower limit of detection (LOD) was 0.16 ng/mL and the lower limit of quantitation (LLOQ) was 0.31 ng/mL of DA in monkey plasma.…”

Discovery of a Potential Human Serum Biomarker for Chronic Seafood Toxin Exposure Using an SPR Biosensor

“…Final extracts were further diluted 10-fold in dilution buffer before quantification. For HPLC-MS/MS analyses, the samples were analyzed using a recently developed and validated HPLC-MS/MS method [35]. In brief, urine samples were extracted with 100% methanol at 1:1 v / v ratio.…”

Chronic, low-level oral exposure to marine toxin, domoic acid, alters whole brain morphometry in nonhuman primates

“…Daily, oral exposure to DA was initiated after this 2-month run-in period, and blinded testers orally administered 1 ml of either 0 (n=10), 0.075 (n=11), or 0.15 (n=11) mg/kg of DA in 5% sugar water for at least 2 months. All dosing solutions were quality controlled by measuring DA concentrations via validated LC-MS/MS methods (Shum et al, 2018). After at least two months of exposure, enrolled females were bred with treatment naïve males, and dosing continued throughout breeding and pregnancy.…”

“…Plasma DA concentrations were monitored with unsedated blood draws from the saphenous vein, taken 5 hours after dosing. Blood was drawn into sodium heparin tubes and centrifuged at 3,000 g. Plasma was separated, stored at −20° C, and analyzed using the methods detailed in Shum et al, 2018. Before pregnancy, average plasma DA concentrations were 1.31 ng/ml for the 0.075 mg/kg/day DA group and 3.42 ng/ml for the 0.15 mg/kg/day DA exposure group.…”