Detection of human exposure to saxitoxin and neosaxitoxin in urine by online-solid phase extraction-liquid chromatography–tandem mass spectrometry. (1st June 2015)

• Record Type: Journal Article
• Authors: Bragg, William A.; Lemire, Sharon W.; Coleman, Rebecca M.; Hamelin, Elizabeth I.; Johnson, Rudolph C.
• Is Part Of: Toxicon. Volume 99(2015)
• Page Start: 118
• Page End: 124
• Publication Date: 2015-06-01
• Subjects: Marine toxins -- Saxitoxin -- Neosaxitoxin -- LC-MS/MS -- Online SPE; Toxins -- Periodicals; Venom -- Periodicals; 615.9
• DOI: 10.1016/j.toxicon.2015.03.017
• Languages: English
• ISSNs: 0041-0101

Abstract

Abstract: Saxitoxin (STX) and neosaxitoxin (NEO) are potent neurotoxins that cause paralytic shellfish poisoning (PSP). PSP typically occurs through the ingestion of bivalve shellfish that have consumed toxin producing dinoflagellates. Due to initial presentation of symptoms being nonspecific, a clinical measurement is needed to confirm exposure to these toxins. Our group has developed an online solid phase extraction hydrophilic interaction liquid chromatography (HILIC) method for the analysis of STX and NEO in human urine with tandem mass spectrometry. A unique feature of this online method is the incorporation of a new synthetic 15 N4 -STX labeled internal standard used for quantitation. Manual sample preparation time was reduced by approximately 70% for 98 urine samples as compared to a previously reported method. The lowest reportable limit for STX was improved from 5.0 ng/mL to 1.01 ng/mL and from 10.0 ng/mL to 2.62 ng/mL for NEO. Three analysts validated the method with 20 calibration curves total over 30 days with precision and accuracy within ±15% for all QCs. This new online method rapidly identifies STX and NEO exposure with improved sensitivity, which can facilitate the work of public health authorities to confirm the cases of PSP, complementing the many shellfish monitoring programs worldwide. Highlights: First online-SPE-HILIC-MS/MS method for saxitoxin and neosaxitoxin developed. Better sensitivity and specificity compared to our previous method developed. Online SPE saves time and resources during development and implementation. Use of a commercially available isotopically labeled internal standard.