Analysis of furan and its major furan derivatives in coffee products on the Chinese market using HS-GC-MS and the estimated exposure of the Chinese population.

The current study analysed concentrations of furan and its derivatives in coffee products commercially available in China based on an improved headspace gas chromatography-mass spectrometry (HS-GC-MS) method and estimated health risks. A total of 101 samples of coffee products on the Chinese market was analysed. Furan (98%, ND-6569 µg/kg) and 2-methylfuran (100%, 2-29639 µg/kg) were the compounds with the highest concentrations and detection rates in coffee products. The mean dietary exposure of Chinese consumers to furan and the sum of furan, 2-methylfuran and 3-methylfuran in coffee products was 0.09 and 0.46 µg/kg bw/day, respectively. For the neoplastic effects of furan, the margin of exposure (MOE) was 14,556 for the mean dietary exposure of consumers. For the non-neoplastic effects of furan, MOEs were 711 and 139 for furan and the sum of furan, 2-methylfuran and 3-methylfuran, respectively. Overall, a health concern is indicated for coffee consumers with MOEs below 10000.

Concentration of morpholine residues in major fruits and juices and its dietary exposure in China.

Morpholine is a common chemical used as emulsifier in the preparation of wax coatings for some fruit to help them remain fresh and protect against insects and fungal contamination. It has been reported that morpholine has acute toxic effects on rodents. In the present study, morpholine concentrations were analysed in fruits (citrus fruits, apples, strawberries and grapes) and juices (apple juice and orange juice) in order to determine dietary exposure among the Chinese population. A total of 732 fruit and juice samples were collected during 2015-2016, which covered major foods in China. Fruit and juice consumption data were taken from China National Nutrient and Health Survey (2002) and include data from 16,407 fruit or juice consumers. It was found that mean dietary exposure to morpholine residues from fruits and/or juices for general Chinese consumers and children 2-6 years old were 0.42 and 1.24 µg/kg bw/day, respectively. The 97.5% intake in general Chinese consumers and children 2-6 years old were 2.25 and 6.90 µg/kg bw/day, respectively. The primary food sources of the morpholine dietary intake of general Chinese consumers were citrus fruits (57.4%) and apples (40.8%). These findings suggested that dietary exposure to morpholine in the Chinese population was lower than the acceptable daily intake of morpholine, and there are no health concerns.

Dietary Exposure to Benzyl Butyl Phthalate in China.

OBJECTIVE: Benzyl butyl phthalate (BBP) is a plasticizer used in food contact materials. Dietary exposure to BBP might lead to reproduction and developmental damages to human. The present paper was aimed to assess the health risk of BBP dietary exposure in Chinese population. METHODS: The BBP contents were detected in 7409 food samples from 25 food categories by gas chromatography-mass spectrometry operated in selected ion monitoring (SIM) mode. The dietary exposures of BBP in different age and sex groups were estimated by combining the content data with food consumption data derived from 2002 China National Nutrient and Health Survey, and evaluated according to the tolerable daily intake (TDI) of BBP established by European Food safety Agency. RESULTS: It was found that BBP was undetectable in most samples and the highest level was 1.69 mg/kg detected in a vegetable oil sample. The average dietary exposure of BBP in people aged ⋝2 years was 1.03 µg/kg bw per day and the highest average exposure was found in 2-6 years old children (1.98 µg/kg bw per day). The BBP exposure in 7-12 months old children excessed 10% of tolerable daily intake (TDI) in worst scenario. . CONCLUSION: The health risk of BBP dietary exposure in Chinese population is low and, considering BBP alone, there is no safety concern.

Levels and potential health risk of heavy metals in marketed vegetables in Zhejiang, China.

The present study analyzed 5785 vegetables for concentrations of As, Cd, Cr, Pb, Ni and Hg, and estimated the health risk to local consumers by deterministic (point estimates) approaches. Levels of elements varied in different vegetables. Average levels of As, Cd, Cr, Ni, Hg and Pb were 0.013, 0.017, 0.057, 0.002, 0.094 and 0.034 mg/kg (fresh weight), respectively. The samples with 0.25% for Cd and 1.56% for Pb were exceeding the maximum allowable concentrations (MACs) set by the Chinese Health Ministry. No obvious regular geographical distribution for these metals in vegetables was found in areas of Zhejiang, China. The mean and 97.5 percentile levels of heavy metal and metalloid were used to present the mean and high exposure assessment. The health indices (HIs) were less than the threshold of 1 both in mean and high exposure assessment. It indicates that for the general people there is very low health risk to As, Cd, Cr, Pb, Ni and Hg by vegetable intake.

Comparison of different calibration approaches for chloramphenicol quantification in chicken muscle by ultra-high pressure liquid chromatography tandem mass spectrometry.

Matrix-dependent signal suppression often occurs in quantitative analysis by ultra-high pressure liquid chromatography tandem mass spectrometry (UPLC-MS/MS). In this study, we investigated three calibration methods for compensation of signal suppression on chloramphenicol (CAP) quantification in chicken muscle. The data showed that the spiking recoveries by solvent standard calibration with a stable isotope labelled internal standard (SIL-IS) and matrix-matched standard calibration with a SIL-IS were significantly higher than by external matrix-matched standard calibration (P < 0.05). When the SIL-IS was used, standards prepared in the mobile phase solvent showed no significant difference as those prepared in the matrix (P > 0.05). The limit of detection (LOD) for external matrix matched standard calibration was 0.1 µg kg(-1), and that for SIL-IS calibration (including matrix matched and solvent dissolved standard) was 0.03 µg kg(-1).

Concentration of di(2-ethylhexyl) phthalate (DEHP) in foods and its dietary exposure in China.

Di(2-ethylhexyl) phthalate (DEHP) is a common plasticizer used in food contact materials that has been reported as an endocrine disruptor. In the present study, DEHP concentrations were analyzed in foods in order to determine dietary exposure among the Chinese population, including the general population (aged 2-100) and four age group, that is children aged 2-6, adolescent aged 7-12, young people aged 13-17 and adults aged 18 years old and above. 1704 food samples were collected during 2011-2012 and categorized into 12 food groups which covered major foods in China. Food consumption data were taken from China National Nutrient and Health Survey which was performed in 2002 and includes data from 68,959 subjects. Mean concentrations of DEHP were combined with individual food consumption data to estimate dietary exposure. It was found that DEHP levels in foods ranged from not detected to 3.41 mg/kg, with highest mean values in meat (0.23 mg/kg) and vegetable oils (0.21 mg/kg). Mean dietary intakes of DEHP in the general population, children, and adults were 2.34, 4.51, 2.03 µg/kg bw per day, respectively. The 97.5% intakes in these populations were 5.22, 8.43, 3.64 µg/kg bw per day, respectively. The main food sources of DEHP dietary intake were cereals (39.44%), drinking water (16.94%) and meat (15.81%) in children, and cereals (44.57%), meat (15.70%) and drinking water (12.28%) for adults. These findings suggested that dietary exposure to DEHP among Chinese population was lower than tolerable daily intake of DEHP and there are no health concerns based on generally accepted exposure limits.

Health risk assessment of heavy metals in rice to the population in Zhejiang, China.

Environmental pollution with toxic heavy metals can lead to the possible contamination of the rice. Selected metals (As, Cd, Hg and Pb) and their accumulation in rice collected from Zhejiang, China were analyzed to evaluate the potential health risk to the local adults and children. The mean levels found in rice were as follows: As, 0.080 mg/kg; Cd, 0.037 mg/kg; Hg, 0.005 mg/kg; Pb, 0.060 mg/kg. The estimated daily intakes (EDIs) were calculated in combination of the rice consumption data. The mean intakes of As, Cd, Hg and Pb through rice were estimated to be 0.49, 0.23, 0.03 and 0.37 µg/kg bw/day for adults, and 0.34, 0.29, 0.04 and 0.47 µg/kg bw/day for children. The 97.5th percentile (P97.5) daily intakes of As, Cd, Hg and Pb were 1.02, 0.64, 0.37 and 1.26 µg/kg bw/day for adults, and 0.63, 0.83, 0.47 and 1.63 µg/kg bw/day for children. The risk assessment in mean levels showed that health risk associated with these elements through consumption of rice was absent. However, estimates in P97.5 level of Cd and Pb for children, and Hg for adults have exceeded the respective safe limits.

Validation (in-house and collaboratory) of the quantification method for ethyl carbamate in alcoholic beverages and soy sauce by GC-MS.

A method for ethyl carbamate (EC) determination in alcoholic beverages and soy sauce was developed by GC-MS. We adopted the diatomaceous earth solid-phase extraction (SPE) column and elution solvent of ethyl acetate/diethyl ether (5:95 v/v) for sample cleaning. The in-house validation showed the limit of quantification (LOQ) was 5.0 µg/kg. In the accuracy assay, the total average recovery for was 96.7%. The relative standard deviations (RSDs) were <5%. Subsequently, a collaborative trial was organized for the further validation. The RSDs for repeatability and reproducibility were 1.2-7.8% and 2.3-9.6% respectively. It indicated that the present method performed well in different laboratories.

[Study on content of ethyl carbamate in yellow rice wine and its change in Zhejiang province].

OBJECTIVE: To understand the content status of ethyl carbamate (EC) in yellow rice wine and the changes in storage period and shelf life in Zhejiang province. METHODS: A total of 475 samples of yellow rice wine purchased randomly from supermarkets and food stores in Zhejiang province during 2008-2012, and 49 samples collected from manufacturers were measured for EC content. The sample collected from manufacturers by filter sterilization was placed at 4 °C, room temperature and 37 °C for 400 d, respectively;a bottled wine and a wine in bag were bought from market were placed for 400 d in room temperature to conduct shelf life storage test, and measure the content in every point in 2011. The EC of the samples was determinated by gas chromatography-mass spectrometry after the samples were diluted with D5-EC isotope dilution technique, and purified by alkaline diatomite solid phase extraction column. RESULTS: The overall detection rate of EC was 99% (472/475) in yellow rice wine of Zhejiang province in 2008-2012, the median value was 70-112 µg/kg, the 90th percentile was 190-333 µg/kg, the 95th percentile was 214-393 µg/kg, and the maximum value was 430-515 µg/kg. The content of EC was increased gradually along with the increasing of storage age in commercially yellow rice wine, and the average content of EC were positively correlated with storage age(r = 0.988). The contents of EC in yellow rice wine after sterilization increased from 74 µg/kg to 86 µg/kg, 127 µg/kg and 509 µg/kg at 4 °C, room temperature and 37°C, respectively for 400 d storage, the differences had statistical significance (F = 14.73, P < 0.01). The content of EC in yellow rice wines in shelf life, which stored in room temperature with bottle and bag package, was decreased slightly with increasing storage time in the beginning, from 215 to 184 µg/kg and 196 to 158 µg/kg, respectively, and increased again with increasing storage time after 250 d, with 252 µg/kg and 210 µg/kg in bottle and bag package after 400 d, respectively, the differences had statistical significance (Z = 2.37, P < 0.05). CONCLUSION: EC is widespread in rice wine, the content of EC was correlated with storage time and temperature.

[Detection of methyl carbamate and ethyl carbamate in yellow rice wine by gas chromatography-mass spectrometry].

OBJECTIVE: To establish the method of simultaneous determination of methylcarbamate (MC) and ethylcarbamate (EC) in yellow rice wine by gas chromatography-mass spectrometry (GC/MS). METHODS: MC and EC in yellow rice wine were derived by 9-xanthydrol, and then the derivants were detected by GC/MS; and quantitatively analyzed by D5-EC isotope internal standard method. RESULTS: The linearity of MC and EC ranged from 2.0 µg/L to 400.0 µg/L, with correlation coefficients at 0.998 and 0.999, respectively. The limits of quantitation (LOQ) and detection (LOD) were 0.67 and 2.0 µg/kg. When MC and EC were added in yellow rice wine at the range of 2.0-300.0 µg/kg, the intraday average recovery rate was 78.8%-102.3%, relative standard deviation was 3.2%-11.6%; interday average recovery rate was 75.4%-101.3%, relative standard deviation was 3.8%-13.4%. 20 samples of yellow rice wine from supermarket were detected using this method, the contents of MC were in the range of ND (no detected) to 1.2 µg/kg, the detection rate was 6% (3/20), the contents of EC in the range of 18.6 µg/kg to 432.3 µg/kg, with the average level at 135.2 µg/kg. CONCLUSION: The method is simple, rapid and useful for simultaneous determination of MC and EC in yellow rice wine.

[The determination of phthalic acid esters in edible vegetable oils by gas chromatography-mass spectrometry].

OBJECTIVE: We aimed to establish a quantified method for the 17 phthalate acid esters (PAE) in edible vegetable oil by gas chromatography-mass spectrometry (GC-MS) with the pretreatment of acetonitrile extraction and silica/N-(n-propyl)ethylenediamine (silica/PSA) mixed solid phase extraction column and evaluated the PAE of 25 edible oil samples from supermarkets in Hangzhou city. METHODS: The internal standard solution (D4-DEHP) was added in edible vegetable oil sample. The analytes were extracted by acetonitrile with 1 min vortex, and centrifuged at 3050×g for 5 min. The supernatant was then cleaned with silica/PSA column, and eluted with acetonitrile. The elution was dried with N2 flow at 50°C and diluted to 1.0 ml with hexane. Then, 17 PAE were tested by GC-MS and quantified with internal standards. The repeatability and sensitivity of the assay were evaluated. PAE were then determined in 25 plastic buckets of edible vegetable oil from supermarkets in Hangzhou city. RESULTS: By the quantification of internal standard of D4-DEHP, a good linearity range of related 17 PAE was observed. The correlation coefficient was 0.994-1.000 and the standard lowest quantified level was 0.05-0.15 µg/ml. The spiking recoveries of 17 PAE were 78.3%-108.9% with the RSD of 4.3%-12.1% (n=6). The method detection limits were 0.1-0.2 mg/kg. In 25 plastic buckets of edible vegetable oil from Hangzhou, DMP, DEP, DIBP, DBP and DEHP were detected at the range of <0.1-1.8 mg/kg and the detection rates were 12% (3/25), 24% (6/25), 100% (25/25), 96% (24/25) and 100% (25/25), respectively. Other 12 PAE was not detected. For DBP with the level of <0.1 to 1.3 mg/kg, the results of 16% (4/25) samples exceeded the regular migrating limit of 0.3 mg/kg. For DEHP of <0.2-1.8 mg/kg, the data of 12% (3/25) samples were beyond the regular migrating limit of 1.5 mg/kg. CONCLUSION: The pretreatment by silica/PSA mixed solid phase extraction column can satisfy the PAE determination requirements in edible vegetable oils. The DMP, DIBP, DEP, DBP and DEHP were detected from the survey of 25 edible oil samples in Hangzhou city.

Determination of methylmercury in marine fish from coastal areas of Zhejiang, China.

The concentration of methylmercury (MMC) and total mercury (TMC) in marine fishes (five species) frequently consumed in the coastal areas of Zhejiang province, China, was determined. The method of high-performance liquid chromatography-atomic fluorescence spectrometry (HPLC-AFS) with the microwave-assisted extraction was used for the MMC determination. TMC was analysed by a direct mercury analyser. MMC and TMC concentrations in five fish species ranged from 53 to 158 µg kg⁻¹ and 60 to 172 µg kg⁻¹, respectively. The proportion of MMC levels in TMC was greater than 80%. The highest MMC and TMC levels were found in Hairtail.

[Survey and analysis of ethyl carbamate in commercial fermented foods in Hangzhou in 2010].

OBJECTIVE: To observe the ethyl carbamate concentrations in different commercial fermented foods in Hangzhou in 2010. METHODS: In 2010, 237 commercial fermented food samples of eight categories, including yellow wine, white spirit, wine, beer, cooking wine, sauce, vinegar and fermented bean curd, were purchased from 3 different size markets respectively in Hangzhou. The ethyl carbamate was measured by gas chromatography-mass spectrometry in selection ion mode, after the samples were coupled with D5-ethyl carbamate, and purified by diatomite solid phase extraction column. RESULTS: The results showed that ethyl carbamate was detected in all samples analyzed (100%) with the range from 2.0 µg/kg to 515.0 µg/kg. The ethyl carbamate average (median) levels in 8 food categories were descending with fermented red bean curd (182.2 µg/kg (161.2 µg/kg)), yellow wine (159.6 µg/kg (121.0 µg/kg)), cooking wine (86.8 µg/kg (95.6 µg/kg)), white spirit (72.0 µg/kg (60.5 µg/kg)), soy sauce (47.2 µg/kg (40.7µg/kg)), vinegar (26.7 µg/kg (31.8 µg/kg)), wine (15.7 µg/kg (16.8 µg/kg)) and beer (2.2 µg/kg (2.3 µg/kg)). CONCLUSION: The ethyl carbamate was detected in all fermented foods in Hangzhou in 2010, and the levels of ethyl carbamate in red bean curd and yellow wine were higher than others.