Development and validation of a high-throughput online solid phase extraction – Liquid chromatography – Tandem mass spectrometry method for the detection of tetrodotoxin in human urine

• First online-SPE-HILIC-MS/MS method for tetrodotoxin in urine developed.
• Online SPE saves time, resources, and reduces error.
• Highlights problems with surrogate internal standard.

Tetrodotoxin (TTX) is an extremely potent paralytic toxin responsible for yearly illness and death around the world. A clinical measurement is necessary to confirm exposure because symptoms of TTX intoxication cannot be distinguished from other paralytic toxins. Our group has developed an online solid phase extraction hydrophilic interaction liquid chromatography (HILIC) method for the analysis of TTX in human urine with tandem mass spectrometry. The reportable range for the method was 2.80 - 249 ng/mL in urine with precision and accuracy within 15% as determined for all quality control samples. No isotopically-labeled internal standard is available for TTX; thus a surrogate internal standard, voglibose, was investigated to compensate for matrix effects and ionization suppression. However, upon evaluation, voglibose was ineffective for this purpose. This new online method rapidly identifies TTX, facilitating the work of public health authorities and providing support to monitoring programs worldwide.