Determination of polycyclic aromatic hydrocarbons in infant formula using solid state urea clathrate formation with gas chromatography - tandem mass spectrometry.

An analytical method has been developed for the quantitative determination of the 16 EU priority polycyclic aromatic hydrocarbons (PAHs) in infant formula. Prior to analysis infant formula is subjected to sample preparation including the extraction of PAHs from the sample, transesterification of the triglyceride content of the extract to fatty acid methyl esters (FAMEs), and solid state urea clathrate formation to remove the FAMEs. Measurements were carried out with gas chromatography - tandem mass spectrometry. The developed method has been evaluated in terms of trueness, precision (repeatability), limit of detection (LOD), limit of quantification (LOQ), selectivity, sensitivity and linearity. Measurement range of 200-1500ngkg was selected in accordance with the limit values set by the European Commission (835/2011/EC). LOD values were 75ngkg for dibenzo(a,e)pyrene, dibenzo(a,i)pyrene and dibenzo(a,h)pyrene while 50ngkg for the rest of the PAHs (benzo(c)fluorene, benzo(a)anthracene, cyclopenta(cd)pyrene, chrysene, 5-methylchrysene, benzo(b)fluoranthene, benzo(k)fluoranthene, benzo(j)fluoranthene, benzo(a)pyrene, indeno(1,2,3-cd)pyrene, dibenzo(a,h)anthracene, benzo(g,h,i)perylene, dibenzo(a,l)pyrene), LOQ was 200ngkg for all 16 PAHs. Trueness ranged between -29.7 and 29.8% while precision values were between 0.5 and 24.7% (RSD, n=3).