AOACSPIFANMethods-2017Awards

240

Joseph et al.: J ournal of AOAC I nternational V ol. 98, N o . 3, 2015  1121

OFFICIAL METHODS

Determination of Sodium Monofluoroacetate in Dairy Powders by Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS): First Action 2015.02 George Joseph AssureQuality, Blockhouse Bay, 131 Boundary Rd, Lynfield, Auckland 0600, New Zealand

Stakeholder Panel on Infant Formula and Adult Nutritionals Expert Review Panel for Working Group for Sodium Fluoroacetate Darryl Sullivan (Chair) , Covance Martin Alewijn , RIKILT John Austad , Covance Joe Boison , CFIA/Univ of Saskatoon Scott Christiansen , Perrigo Jo Marie Cook , Florida State Dept of Agriculture Jon DeVries , Medallion Labs/General Mills Harvey Indyk , Fonterra George Joseph , AsureQuality Erik Konings , Nestle Alex Krynitsky , U.S. Food and Drug Administration Tom Phillips ,Maryland State Dept of Agriculture Bert Popping , Merieux NutriSciences Murali Reddy , Abbott John Wong , U.S. Food and Drug Administration

(The method has been validated in cow, goat, and sheep dairy powders, and dairy powder formulations. It can be used for other similar matrixes, including liquid milk, provided that it is demonstrated that the method performance values are met.) Specific hazards .— Hydrochloric acid .—Wear personal protective equipment (PPE) and handle in a fume cupboard. Sulfuric acid .—Wear PPE and handle in a fume cupboard. Sodium fluoroacetate .—Wear PPE, including safety glasses and a dust mask, when weighing out the primary material. Potassium hydroxide .—Wear PPE and handle in a fume cupboard; avoid inhalation of dust. 3-Nitroaniline .—Wear PPE, including safety glasses; avoid inhalation. Phosphoric acid .—Wear PPE and handle in a fume cupboard. Sodium fluoroacetate (Figure 2015.02A ) is a rodenticide used in New Zealand to control rats, possums, and rabbits. It is commonly known by its original registration number as compound 1080, but may also be known as sodium monofluoroacetate and fluoroacetic acid sodium salt. A. Principle Samples are dissolved in water and extracted into acetone to allow precipitation of proteins. After centrifugation, the solutions are passed through an anion exchange column and eluted with acid to give free fluoroacetic acid. This acid is converted to 2-fluoro-3’-nitroacetanilide via a carbodiimide- mediated amide coupling reaction. The derivative is then subjected to SPE cleanup, eluting with t -butyl methyl ether (TBME)– n -hexane, concentrated and quantified by LC-MS/MS using derivatized isotopically substituted sodium fluoroacetate as an internal standard. The method reports the analyte as fluoroacetic acid. B. Apparatus Note : Where specific equipment is listed, other brands or models may be used provided that they have equivalent performance. Laboratory equipment .— ( a )  Air displacement pipets.— 5000 μL, with long tips. ( b )  Autosampler vials .—2 mL with tapered glass inserts. ( c )  Balance .—2 or 3 decimal top pan. ( d )  Balance .—5 decimal place analytical. ( e )  Centrifuge .—Capable of centrifuging 15 and 50 mL tubes at 4200 × g RCF. ( f )  Centrifuge tubes .—15 and 50 mL, tapered polypropylene. ( g )  Extraction cartridges .—Oasis HLB 60 mg. ( h )  Glass reservoirs .— Ground glass, 19/26 joint, approximately 20 mL.

Submitted for publication April 2015. Adopted as a First Action Official Method by the Expert Review Panel on Sodium Monofluoroacetate and approved by the Stakeholder Panel on Infant Formula and Adult Nutritionals (SPIFAN).

Approved on: March 17, 2015. DOI: 10.5740/jaoac.int.2015.02