Phthalate concentrations in personal care products and the cumulative exposure to female adults and infants in Shanghai.

Phthalate esters (PE) are synthetic chemicals widely used in industry, and have been detected in personal care products (PCP). Recent findings of human reports demonstrated endocrine-disrupting action associated with phthalate exposures. The aims of this study were to (1) measure levels of 11 PE in 198 PCP collected from retail markets in Shanghai and (2) assess daily dermal exposure in adult females and infants. The health risk of cumulative exposure to eight PE on reproductive system function derived from dermal PCP use was further assessed by utilizing the hazard index (HI) approach. Diethyl phthalate (DEP) was the most frequently detected compound (29.8%), followed by diisobutyl phthalate (DiBP) (6.6%). The geometric mean (GM) concentrations of daily exposure to DEP, bis(2-methoxyethyl) phthalate (DMEP), DiBP, dibutyl phthalate (DBP), diphenyl phthalate (DPP), and bis(2-ethylhexyl) phthalate (DEHP) in female adults were 0.018, 0.012, 0.002, 0.001, 0.003, and 0.002 µg/kg body weight (bw)/d, respectively. The GM daily exposure levels to PE in infants and adult females were similar except for DEHP, which was higher in infants. DEP exposure was highest in both subpopulations at either GM or maximal level. All HI of 8 PE were far less than 1, ranging from 0.0002 to 0.005, indicating no cumulative reproductive risks to these populations. DBP, DMEP, and DEHP were three major contributors to the cumulative HI. In summary, the level of phthalate in PCP from Shanghai retail markets posed no apparent cumulative risk to adult females and infants in China.

[Determination of 12 bisphenol substances in functional foods by QuEChERS and high performance liquid chromatography-tandem mass spectrometry].

A method based on high performance liquid chromatography-tandem mass spectrom- etry (HPLC-MS/MS) for the simultaneous determination of 12 bisphenol substances in functional foods (powder, tablet, capsule) was presented. The samples were extracted by acetonitrile containing 1% (v/v) acetic acid followed by further cleaned up using matrix solid-phase disper- sion to remove matrix interferences. The separation of the 12 bisphenol substances was performed on a Thermo Aquasil C18 column (150 mm x 4.6 mm, 3.0 µm), and determined in the positive and negative MRM modes by MS/MS using matrix-matched external standard method. The results demonstrated that the calibration curves were of good linearity with the correlation coefficients greater than 0.99. The limits of detection (LODs, S/N > 3) were in the range of 0.1-0.5 µg/kg and the limits of quantitation (LOQs, S/N > 10) were 0.4-1.7 µg/kg. The recoveries of the 12 bisphenol substances spiked at three levels (2.0, 5.0 and 10.0 µg/kg) in matrix ranged from 60.5% to 116.3% with the relative standard deviations (RSDs) of 6.8% to 11.2%. The established method is simple, time-saving and sensitive. It can meet the requirements for current regulations while achieving qualitative and quantitative determination of the 12 bisphenol substances in functional foods.

[Determination of metabolite residues of nitrofuran antibiotics in aquatic products by liquid chromatography-tandem mass spectrometry].

A method was developed for simultaneous qualitative and quantitative analysis of five metabolites of nitrofuran antibiotics, including 3-amino-2-oxazolidinone (AOZ), 5-morpholino-methyl-3-amino-2-oxazolidinone ( AMOZ ), semicarbazide ( SEM ), 1-aminohydantoin (AHD) and 3, 5-dinitrosalicylic acid hydrazide (DNSH) in aquatic products by liquid chromatography-tandem mass spectrometry (LC-MS/MS). The samples were hydrolyzed with HCl, and derivatized with 2-nitrobenzaldehyde at 37 degre C for 16 hours. The derivative solutions were adjusted to pH 7.0 -7. 5, and the analytes were extracted by ethyl acetate. The separation was based on Thermo Aquasil C18 column (150 mm x 4.6 mm, 3.01 micro m). The analytes were detected by tandem mass spectrometry with electrospray ionization source with multiple reaction monitoring (MRM) mode. The developed method showed good linear correlation between the peak area ratios of the analyte and the internal standard and the concentration of the analyte with the correlation coefficients all above 0. 99 over the dynamic range of 0.5 - 10 micro g/kg. The limits of quantitation (LOQs) of AOZ, AMOZ, SEM, AHD and DNSH were 0.5 micro g/kg. The average recoveries of all the compounds at four spiked levels of 0.5, 1.0, 2.0 and 4. 0 micro g/kg ranged from 81.3% to 100.5% with the RSDs between 3.4% and 10.0% (n =6). The method is proved to be fast and effective for simultaneous qualitative and quantitative analysis of the metabolites of the nitrofuran antibiotics in aquatic products.

[Determination of four plant growth regulator residues in amphisarcas by high performance liquid chromatography-tandem mass spectrometry].

A high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method was developed for the determination of the plant growth regulator (PGR) (paclobutrazol, forchlorfenuron, isopentennyladenine and 6-benzylaminopurine) residues in amphisarcas. The sample was extracted with acetonitrile, then cleaned up by MCX solid phase extraction. The HPLC separation was performed on an Agilent XDB-C18 column with 5 mmol/L ammonium acetate solution and acetonitrile containing 0.1% (volume percentage) formic acid as the mobile phases in a gradient elution mode. The PGRs were determined by MS/MS in positive electrospray ionization mode, and quantified by matrix-matched external standard method. The calibration curves showed good linearity in each range with correlation coefficients greater than 0.999. The limits of quantification (LOQs, S/N > 10) were 0.04-1.35 g/kg and the limits of detection (LODs, S/N > 3) were 0. 01-0 41 microg/kg for the four PGRs spiked in cucumber and apple. The recoveries of the four PGRs spiked at three levels ranged from 81.0% to 93.%, with the relative standard deviations (RSDs) of 3.5%-9.5%. The sensitivity, accuracy and precision of the method meet the technical standards of the pesticide determination. Therefore the method can be applied to the determination of the four PGRs in amphisarcas.

[Determination of 14 heterocyclic aromatic amines in wine by liquid chromatography-ion trap-time of flight tandem mass spectrometry].

A rapid qualitative and quantitative analytical method was developed for the simultaneous determination of 14 heterocyclic aromatic amines (HAAs) in wine by liquid chromatography-ion trap-time of flight tandem mass spectrometry (LC-IT-TOF MS). HAAs were extracted from the samples by ethyl acetate under alkaline condition. The quantitation was carried out using internal standard method. The separation of HAAs was carried out based on Phenomenex Kinetex C18 100A column (100 mm x 2.1 mm, 2.6 microm), with a gradient elution of acetonitrile and 30 mmol/L ammonium formate at a flow rate of 0.4 mL/min. The analytes were detected under positive-ion electrospray ionization mode. The results showed that the linear ranges of the 14 HAAs were 1-500 microg/L with limits of detection (signal/noise = 3) of 0.33-1.77 microg/L. The average recoveries of all the compounds spiked in wine samples at three levels of 10, 50, 100 microg/L were in the ranges of 71.6%-96.4%, 72.9%-101.9%, 74.5%-103.3%, with the corresponding relative standard deviations (RSDs, n = 6) of 2.9%-7.9%, 1.7%-5.3%, 1.8%-4.8%, respectively. The established method is simple, rapid, accurate, and has wide linear range and high sensitivity. It can be applied to the simultaneous analysis of the HAAs in wine.

[Identification of irradiated abalone by ESR spectroscopy].

OBJECTIVE: To establish an analytical method for the detection and identification of irradiated abalone by electron spin resonance spectroscopy. METHODS: Electron spin resonance (ESR) was used to study the spectral characteristics of abalone and the characteristic peak for quantitation. RESULTS: There were obvious different ESR spectra between unirradiated and irradiated abalone. The g factor for unirradiated abalone was 2.0055-2.0060, the g1 and g2 factor for irradiated abalone were (2.0027 +/- 0.0001) and (1.9994 +/- 0.0001), respectively. The ESR signal intensity of characteristic peak was positively correlated with absorbed dose in the range of 0.5 - 10 kGy, left peak was the characteristic peak for quantitation and the detection limit was < or = 0.5 kGy. It was difficult to quantitate when the absorbed dose was over 10 kGy. ESR characteristic peak and g factor were able to qualitatively determine the irradiation of abalone. CONCLUSION: ESR spectroscopy is an effective method to determine whether the abalone being irradiated or not.