An LC/MS/MS analysis method was developed for crustacean allergens, tropomyosin, and arginine kinase. A protein extract from shrimp was reduced, alkylated, and digested by trypsin. Peptide spectra were obtained using full scan analysis by LC/MS/MS, and we determined a sequence through a protein search. 22ADTLEQQNK30, 92IQLLEEDLER101, 113LAEASQAADESER125, 134SLSDEER140, 153FLAEEADR160, and 190IVELEEELR198 of tropomyosin and 152VSSTLSSLEGELK164 and 217TFLVWVNEEDHLR229 of arginine kinase were selected as the specific peptides, and optimal multiple-reaction monitoring conditions were used. The results obtained through the LC/MS/MS analysis correlated well with those using the ELISA method for various crustacean samples (r2>0.9). Moreover, unregulated species, such as krill or insects, which produce positive results in some crustacean ELISA assays, can be differentiated by LC/MS/MS. These findings suggest that LC/MS/MS analysis may be effective for crustacean food allergen analysis.

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An analytical method for the determination of butroxydim in agricultural products by LC-MS was developed. Butroxydim was extracted with acetonitrile and an aliquot of the crude extract was cleaned up on an octadecyl silanized silica gel (C18) cartridge column (1,000 mg), followed by a salting-out step to remove water. Before purification on a silica gel (SI) cartridge column (690 mg), polar matrices were precipitated by adding ethyl acetate, n-hexane and anhydrous sodium sulfate successively. This process effectively removed caffeine and catechins and improved recovery when analyzing residual butroxydim in tea leaves. Recovery and repeatability were good; the relative standard deviations were less than 5% for all 12 tested agricultural products (brown rice, soybean, potato, spinach, cabbage, apple, orange, grapefruit, lemon, tomato, peas with pods, and tea). Average recoveries for 11 agricultural products, except for lemon, were 74-92%.

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