کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5136359 | 1494009 | 2017 | 14 صفحه PDF | دانلود رایگان |
- A GC method for monitoring PAH contamination of cocoa beans is proposed.
- Plackett-Burman and central composite designs were applied for optimization.
- The method was validated according to EC criteria for 8 high-molecular weight PAHs.
- Significant matrix effects were observed for chrysene and benzo[b]fluoranthene.
- This method is appropriate for Brazilian monitoring programs.
An accelerated solvent extraction (ASE) procedure for use with gas chromatography-mass spectrometry (GC-MS) was optimized for the determination of eight polycyclic aromatic hydrocarbons (PAHs) in cocoa beans. Plackett-Burman and rotatable central composite design (RCCD) indicated that three variables affected the recoveries of PAHs during the extraction and purification steps: agitation time in the second liquid-liquid partition, weight of silica gel in the column, and volume of hexane for PAH elution from the column. After obtaining the optimal conditions, a single laboratory method validation was performed. Linearity was demonstrated for benzo[a]pyrene in the concentration range from 0.5 to 8.0 mg kgâ1 of sample, corresponding to 1.25-20.0 μg kgâ1 of cocoa on a fat basis. For the other analytes, linearity was observed from 0.75 to 8.0 μg kgâ1 of sample (1.88-20.0 μg kgâ1 of cocoa on a fat basis). Significant matrix effects were found for chrysene and benzo[b]fluoranthene. The precision of the method was verified with relative standard deviations (RSDs) ranging from 2.57 to 14.13% and from 4.36 to 19.77% under repeatability and intermediate precision conditions, respectively. The average recoveries of the eight PAHs ranged from 74.99 to 109.73%. These parameters, limits and measurement uncertainties met the performance criteria established by European Union regulations, except for the theoretical limit of detection for chrysene. The method was applied to the analysis of samples of Brazilian cocoa beans, and only one sample was found to have a PAH content above the maximum limit defined by the European Union legislation. This optimized and validated method is intended to be used as part of the official Brazilian monitoring programs investigating contaminants and residues in food.
Journal: Journal of Chromatography B - Volume 1053, 15 May 2017, Pages 87-100