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A simple sample preparation method requiring minimal organic solvents is proposed for the determination of the total phthalate content in cosmetics by high-performance liquid chromatography-tandem mass spectrometry. The hydrolysis of phthalates and purification of interfering substances were performed in a three-phase system that included an upper n-hexane phase, a middle ethanol phase, and a lower aqueous alkali solution. This three-phase system utilized an incremental purification strategy. The apolar ingredients were extracted with n-hexane, the polar pigments accumulated in the ethanol phase, and the hydrolysis product, phthalic acid, remained in the hydrolysate. Under the optimized conditions, the correlation coefficients ( r) for the calibration curves were 0.998-0.999 in the range 0.60-12 mol L. The limit of detection was 5.1 μmol kg, and the limit of quantification was 9.2 μmol kg. The recoveries varied from 84 to 97% with RSDs equal to or lower than 11%. The intra-day and inter-day repeatability values, expressed as the relative standard deviation, were less than 8.7 and 9.8, respectively. No obvious matrix effect existed in the different cosmetics matrices. The validated method was applied for the analysis of 57 commercial cosmetic samples. [ABSTRACT FROM AUTHOR]

A simple and rapid method based on magnetic solid-phase extraction (MSPE) combined with high-performance liquid chromatography coupled with triple quadrupole mass spectrometry (HPLC-MS/MS) was used for the determination of 15 sulfonamides from milk samples. The extraction and cleanup used a graphene oxide-based magnetic nanocomposite (FeO@GO) as an adsorbent. Various experimental parameters that could affect the extraction efficiencies, such as the amount of FeO@GO, the extraction time, the ionic strength of sample solution, and the type of eluent, were investigated. Under optimized experimental conditions, good linearity was observed in the range of 2.0 to 100.0 μg L for all of the analytes, with correlation coefficients (R) ranging from 0.994 to 0.999. The limits of detection for the method ranged between 0.02 and 0.13 μg L. Mean values of the relative standard deviation of intraday and interday precision ranging from 1.0 to 7.3 % and from 1.7 to 8.1 % were obtained, respectively. The average recoveries were between 73.4 and 97.4 % at three different spiked levels. It was confirmed that the FeO@GO nanocomposite was an effective MSPE material for use in sulfonamide analyses in milk samples. [ABSTRACT FROM AUTHOR]

Pinoresinol diglucoside (PDG) is the important antihypertensive compound in Eucommia ulmoides Oliv., a traditional Chinese herb medicine. The research objective was to certify the possibility of producing PDG through fermentation. PDG-producing endophytic fungi were isolated from E. ulmoides Oliv., and the highest PDG-yielding (11.65 mg/L) isolate, XP-8, was identified as Phomopsis sp. according to the morphological characteristics and the phylogenetic tree constructed on the basis of the gene sequence in the internal transcribed spacers district. The microbial PDG was isolated by using S-8 resin and purified to a purity of 98.7% using preparative high-performance liquid chromatography (HPLC). Information obtained from the UV spectrum (277 and 227 nm, in water solution), infra-red spectrum (3,428; 2,930; 2,877; 1,637; 1,600; and 1,513; 1,460; 1,421; 1,269; 1,223; 1,075; 658 cm, in powder), molecular weight (682 Da, measured using HPLC-electrospray ionization mass spectrometry (ESI/MS) and tandem mass spectrometry), and nuclear magnetic resonance analysis show the microbial PDG is (+)-1-pinoresinol 4,4′-di- O-β- d-glucopyranoside, same as the plant-derived PDG. The microbial PDG is stable in pH range from 3 to 11 but less stable at temperature higher than 90 °C and in light exposure. During the fermentation, PDG production outside cells starts at the later stage of cell growth when the residual sugar in the medium was low. The study reveals the possibility for production of PDG by fermentation. [ABSTRACT FROM AUTHOR]