Surveillance study of a number of synthetic and natural growth promoters in bovine muscle samples using liquid chromatography-tandem mass spectrometry

Classification and detection of testosterone propionate and nandrolone residues in duck meat using surface-enhanced Raman spectroscopy coupled with multivariate analysis

There is a critical need for a rapid and simple method of qualitative and quantitative analysis of testosterone propionate (TP) and nandrolone (NT) residues in duck meat. In this study, we applied surface-enhanced Raman spectroscopy (SERS) coupled multivariate analysis for the classification and detection of TP and NT residues in duck meat. A total of 294 duck meat extract samples were obtained from duck breast meats based on a LC-MS/MS sample preparation method with slight modification including 102 duck meat extract samples without TP and NT, 43 duck meat samples containing TP, 47 duck meat extract samples containing NT, and 102 duck meat extract samples containing TP and NT. Raw Raman spectra were pretreated by using adaptive iteratively reweighted penalized least squares (airPLS), normalization and first derivative, and then the score values of first 10 principal components were selected as the inputs of the developed models. A particle swarm optimization–support vector classification (PSO-SVC) model was created to classify all the duck meat samples into the 4 groups (i.e., control group, TP group, NT group, and TP combined with NT group) with the classification accuracies of 99.49 and 100% for training set and test set, respectively. Furthermore, 2 least squares support vector regression (LS-SVR) models were developed to predict the TP values in samples with a determination coefficient (R²) value of 0.9316, root mean square error (RMSE) value of 2.1739, and ratio of prediction to deviation (RPD) value of 3.2189 for the test set, and NT values in samples with an R² value of 0.9038, RMSE value of 2.2914, and RPD value of 2.9701 for the test set. Surface-enhanced Raman spectroscopy technology, in combination with multivariate analysis, has the potential to become the qualitative and quantitative analysis tool for TP and NT residues in duck meat extract.

Analysis of stilbene residues in aquacultured finfish using LC-MS/MS

This analytical method was developed for the determination of three stilbene residues, diethylstilbestrol (DES), dienestrol (DEN), and hexestrol (HEX), in edible tissues of finfish including catfish, salmon, trout, and tilapia. Fortified fish samples were extracted with acetonitrile and further cleaned up using silica solid phase extraction columns. Stilbene residues were separated from matrix components by reversed phase high-performance liquid chromatography on a C8 column and analyzed using a tandem mass spectrometer with negative electrospray ionization. The overall average residue recoveries using post-fortified matrix-matched calibrants were 119, 99, and 104% with %RSDs of 18, 11, and 15% for DEN, DES, and HEX, respectively. Method detection limits of DEN, DES, and HEX in each matrix were found to be at or below 0.21 ng/g, and the limit of quantification averaged 0.3 ng/g and ranged from 0.18 to 0.65 ng/g for all analytes in all matrices.