Multi-residue analytical method for detecting pesticides, veterinary drugs, and mycotoxins in feed using liquid- and gas chromatography coupled with mass spectrometry.

Modified QuEChERS and triple quadrupole mass spectrometry (LC and GC-MS/MS) technology were used to sequentially analyze pesticides, veterinary drugs, and mycotoxins in feed. In order to analyze the harmful substances that may remain or occur in the feed, we performed optimization experiments for sample preparation and LC-MS/MS and GC-MS/MS conditions. Optimized sample preparation involves extracting 5 g of sample with 15 mL of 0.25 M EDTA and 10 mL of acetonitrile. And some extracts were diluted 10-fold with 100 mM ammonium formate aqueous solution and analyzed by LC-MS/MS, and some extracts were purified through 25 mg PSA and analyzed by GC-MS/MS by adding an analyte protectant. We confirmed the matrix effect of feed ingredients and compound feeds, and added a dilution process after extraction to increase on-site efficiency. Matrix-matched calibration was applied for quantification. Method validation was performed for 197 pesticides, 56 components for veterinary drugs, and 5 components for toxins. All the components showed good linearity (r2 ≥ 0.98) in the developed analytical method. For most compounds, the limit of quantitation was 0.05 mg/kg. The recovery rate experiment was repeated three times at three concentrations including LOQ in feed ingredient, compound feed for livestock, and compound feed for pets. The recovery rate was 70.09-119.76% and relative standard deviations were ≤ 18.91%. And the accuracy and precision were further verified through cross-validation between laboratories. The developed analytical method was used to monitor 414 domestically distributed and imported feeds.

Effect of dietary mixture of gallic acid and linoleic acid on antioxidative potential and quality of breast meat from broilers.

The effect of dietary mixture of gallic acid and linoleic acid (MGL) on the antioxidative potential and quality of breast meat from broilers was investigated. Broilers during the 22-36days on trial received 3 dietary treatments: 1) control (commercial finisher diet), 2) 0.5% MGL (gallic acid:linoleic acid=1M:1M), and 3) 1.0% MGL. The feed efficiency, DPPH radical scavenging activity, ABTS(+) reducing activity, reducing power, TBARS, and total phenolic content in the breast from the broilers improved significantly by 1.0% MGL dietary treatment. Arachidonic and docosahexaenoic acids were higher in the broilers fed both levels of MGL diets. In addition, water holding capacity of the breast was enhanced by the 1.0% dietary MGL treatment and was accompanied by a slight antimicrobial activity (1 decimal reduction) during storage. In conclusion, 1.0% dietary supplementation with MGL can improve the antioxidative potential, and nutritional and functional qualities of broiler breast meat.