Multiresidue analysis of 59 nonallowed substances and other contaminants in cosmetics.

A method was developed for the determination of 59 glucocorticoids, sex hormones, nonsteroidal anti-inflammatory drugs, antibiotics, and other contaminants in cosmetics simultaneously by ultra high performance liquid chromatography coupled with electrospray ionization tandem mass spectrometry. Acetonitrile was used to extract the sample, and the mixed sorbents were dispersed for purification. With the optimal conditions, the optimized pretreatment processes led to no significant interference on analysis from an extremely complicated sample matrix, and the linear ranges of 59 analytes were 0-480.0 µg/kg with the correlation coefficients above 0.99 and the limits of quantification (S/N≥10) were 5-40 µg/kg. Statistical evaluation revealed that the average recoveries were in the range of 61.2-131.2%, and relative standard deviations were in the range of 2.0-22.8%, meanwhile the interday precision ranged from 3.8 to 21.8%. This method is simple, fast, and credible, and it can be applied to simultaneous screening and determination of various classes of substances under investigations illegally presented in cosmetic products, covering a wide diversity of polarities, and pKa values.

Comprehensive screening for multi-class veterinary drug residues and other contaminants in muscle using column-switching UPLC-MS/MS.

A quantitative multi-class analytical method covering more than 226 veterinary drugs and other contaminants in muscle, belonging to different drug families, was developed. The method is based on liquid-liquid extraction, purification by low-temperature clean-up and dispersive solid-phase extraction (D-SPE), and analysis was conducted in two analytical runs by column-switching UPLC coupled with electrospray ionisation and tandem mass spectrometry (UPLC-ESI-MS/MS). For most of the target analytes, the optimised pre-treatment processes led to no significant interference from the sample matrix. The limit of quantification varied from 0.05 to 10 µg kg(-1). Statistical evaluation indicated that average recoveries spiked into pork were in the range from 62.4% to 138.8%, and the relative standard deviations were in the range from 2.8% to 26.6% (intra-day precision). The availability of this method will contribute to a better safety assurance of meat with a significant reduction of both effort and time.