Extensive evaluation of a new LC-MS/MS method to quantify monofluoroacetate toxin in the kidney

Monofluoroacetate (MFA) is a highly lethal toxin which causes death by inhibiting cellular ATP production. The heart and brain are the primary target organs. Acute death is attributed to cardiac fibrillation and/or convulsions. Although it occurs naturally in some plants, a major source of animal intoxication is access to sodium monofluoroacetate (NaMFA) pesticide which continues to be a concern in the US and around the world despite restricted use in some countries including the US. There are also concerns about misuse of this pesticide for malicious poisoning. Currently, a tissue-based diagnostic method for NaMFA intoxication in animals is lacking. There is a critical need by the veterinary diagnostic community for a simple, sensitive, and reliable tissue-based diagnostic test to confirm NaMFA poisoning in animals. We have developed and extensively evaluated a sensitive novel LC-MS/MS method suitable for this purpose. The limits of detection (LOD) and limits of quantitation (LOQ) are 1.7 ng/g and 5.0 ng/g, respectively. The accuracy and precision met or exceeded expectations. The method performance was verified using incurred kidney obtained from animal diagnostic cases. This novel kidney-based method is now available for clinical use and can help with diagnostic purposes, including detecting potential issues related to animal foods.