Rapid and simple micromethod for the simultaneous determination of 3-MCPD and 3-MCPD esters in different foodstuffs

This paper describes for the first time a micromethod for the simultaneous determination of 3-monochloropropane-1,2-diol (3-MCPD) and fatty acid esters of 3-MCPD (3-MCPD esters) in different foodstuffs. 3-MCPD and 3-MCPD esters were isolated from food products using a single extraction step separating hydrophilic and lipophilic compounds. An aliquot of the aqueous layer was analyzed for the content of 3-MCPD while a part of the organic layer was analyzed for 3-MCPD esters after cleavage with sodium methoxide. After a simple derivatization procedure with phenylboronic acid (PBA), the determination was achieved by isotope dilution GC-MS using isotope-labeled 3-MCPD and 3-MCPD ester as internal standards. The method was validated for various foodstuffs like bakery products, meat and fish products, and soups as well as seasonings with LOD of 1-2 microg/kg (3-MCPD) and 6 microg/kg (3-MCPD esters), respectively. Recoveries ranged within 95 +/- 9% and 96 +/- 10% at spiking levels of 15 and 25 microg/kg in all matrices for 3-MCPD and 84 +/- 9% and 85 +/- 7% at spiking levels of 0.05 mg/kg and 2 mg/kg for 3-MCPD esters. The method avoids tedious and laborious sample preparation and was successfully applied to the rapid screening of samples conforming to the EU performance criteria for methods of analysis for 3-MCPD.