In order to assess the levels of As,Ba,Cd,Pb ingestion through intake of tea,studies were conducted with ten different brands of tea commonly available in Chinese market.Content of As,Ba,Cd,Pb in tea were determined by inductively coupled plasma -optical emission spectrometry (ICP|OES).Also the extraction percents of these elements in boiling water infusion of tea were measured and the species of Ba were analysed.It is concluded that As,Ba,Cd,Pb ingestion through intake of tea don't creat any risk for human health.

For rapidly identifying 5 bifidobacterium species (B.longum,B.breve,B.adolescentis,B.infantis and B.bifidum) often used in functional food,we designed five species-specific oligonucleotide sequences,which were based on the homology analysis of 16s rRNA genes.After being labeled with digoxigenin(DIG) at 3'-end,the sequences were used as probes hybridizing with DNA from these 5 bifidobacteria.These probes showed the desired species specificity,except that the probe for B.infantis had weak cross-reaction with B.breve.The result showed that these 16s rRNA gene probes were specific and effective tools for identifying and detecting Bifidobacteria in food.

For developing the determination method of chromium picolinate in health food by HPLC,extraction method and HPLC operation conditions such as columns,mobile phase had been optimized.Long term stability test of chromium picolinate had been done.Recovery of the standard spiked >93%,the RSD was 3.1,the lowest detection limit was 10.0 mg/kg,the result fits the demand of the analysis of health food.This method can be used in analysis of the content of chromium picolinate in types of tablet and capsule health food.2 years store experiment in room temperature showed that chromium picolinate was stable.

Objective A rapid method was constructed for detection of 3 kinds of phosphodiesterase 5 (PDE5) inhibitors (sidenafil,vardalafil,tadalafil) in invigorative health food by paper spray ionization mass spectrometry (PSI-MS method).Methods The characteristic ions of the PDE5 inhibitors could be used for preliminary identification and semiquantitative analysis with internal standard method using PSI-MS method.Results The 24 kinds of commercially available health-care products includes capsule,tablet,pill,powder,wine,syrup and liquid were tested.Results from PSI-MS were consistent with the HPLC-UV date.The calibration curves of PSI-MS has a good linearity in a given range.The linear coefficients of analytes were higher than 0.99.The LODs of 3 kinds of PDE5 inhibitors were lower than 1.0 mg/L.The RSDs of this method ranged from 20％ to 24％.Conclusion The PSI-MS method was rapid,accurate and targeted,which is compliant for quickly screening the PDE5 inhibitors in large complex matrix samples.

Objective An analytical method for rapid screening and confirmation of multiple pesticide residues in vegetable and fruit was established according to GB 2763-2014 national food safety standard-maximum residue limits for pesticides in food,using ultra performance liquid chromatography-Q-time of flight mass spectrometry (UPLC-Q-TOF-MS).Methods Pesticide residues in vegetable and fruit were screened by comparing the accurate mass,isotope distribution and abundance in the accurate mass database,and confirmed by comparing with the spectra in the spectra library or by the spectral analysis method.Results The method was verified by spiked samples,and all pesticides were detected at the addition level of 10.0 and 50.0 μg/kg.The recovery of 90％ of the pesticides was in the range of 70％-120％,with relative standard deviation (RSD) ≤ 20％ (n =5).The method was applied to screen pesticides in 30 samples of vegetables and fruits.Twenty-seven pesticides were found and 2 samples exceeded the limit.Conclusion The method was sensitive,accurate and reproducible.Hundreds of pesticides in GB 2763-2014 could be screened and confirmed in a short period of time even without standard substance.It could provide an effective method for food safety control.

Objective To investigate a poisoning caused by wild mushrooms and to identify the toxin in these mushrooms.Methods Epidemiological investigation,blood test and mushroom toxin were analyzed.Results This incident was taken place in one family,and all family members were dead.Multiple organ damage was observed in all patients;amatoxins and virotoxins were detected in both mushrooms and the soup,but were not detected in blood samples because of dialysis.Conclusion The incident was caused by wild mushrooms and public education shoud be strenthened to urge people to avoid eating wild mushrooms and go to the hospital immediately if poisoning takes place.

Objective To investigate the contamination and dietary intake of the aluminium in commercial foods in Shaanxi Province,and evaluate its potential health risks in Shaanxi population.Methods Six hundred and sixty-six samples from 8 kinds of foods in Shaanxi Province were collected from 2013 to 2015.The aluminium contents were detected according to National Food Contamination and Harmful Factors in Risk Monitoring Manual,and dietary intake of aluminium in Shaanxi population was evaluated by point assessment model with of nutritional survey date.Results The average dietary intake of aluminium was 0.154 9 mg/kg BW per day,and the dietary intake of woman aged 18 to 59 years old was the highest,with an average of 0.178 5 mg/kg BW per day.When aluminum intake of the 97.5 percentile,the dietary intake of aluminium in children aged 2 to 7 years old was the highest.The margins of safety (MOS) of all age groups were smaller than 1,while the MOS of high exposure (P97.5) group was above 1.Fried and baked food were the main sources of aluminium exposure in two age groups (2-7 years and 8-12 years old group),while fried food,cold noodle and starch products were the main sources of aluminium exposure for others.Conclusion Dietary intake (tP97.5) of aluminium exceeded the provisional tolerable weekly intake (PTWI).The dietary intake of aluminium in women and children was high.Fried food was the main sources of aluminium exposure in all age groups.

Objective This report aims to assess the exposure risk of aflatoxin B1 in edible vegetable oil in Guangxi.Methods By using margin of exposure (MOE),the report analyzes the dietary exposure of aflatoxin B1 in edible vegetable oil with the data from contamination survey and dietary intake survey.Results For the vegetable oil sample,the content of aflatoxin B1 was between 0.50-320.00 μg/kg.The detection rate of peanut oil was 78.08％ (114/146) which was higher than other vegetable oil,and the exceeding rate was 31.51％ (46/146).For peanut oil,the average content was 30.80 μg/kg,the dietary exposure of the population was 17.30 ng/kg BW,and the MOE was 18.For the prepackaged peanut oil samples,the average content of aflatoxin B1 was 6.33 μg/kg,which was below the limit.While for the bulk peanut oil,the average content of AFB1 was 41.50 μg/kg,which was more than 1.08 times of the limit,and the dietary exposure was 25.59 ng/kg BW.The MOE of bulk peanut oil was 12,1/8 of the prepackaged peanut oil.Conclusion Food safety regulators should pay more attention to bulk peanut oil products,the priority in the risk management measures.At the same time,related department should also promote healthy education for the residents.

Objective The aim of this study was to determine the content of phthalate in disposable plastic tableware sold on Chengdu market,and to provide primary data for safety evaluation.Methods Sample selection was based on stratified sampling.Sixteen phthalate compounds were investigated in 60 disposable plastic tableware,divided into seven groups.The analysis was performed by gas chromatography-mass spectrometry (GC-MS).Results In this survey,diethyl phthalate,diisobutyl phthalate,dibutyl phthalate and diethylhexyl phthalate were detected,while the other 12 phthalate compound were not.The positive rates of the four detected phthalate were 6.7％ (4/60),10.0％ (6/60),46.7％ (28/60) and 28.3％ (17/60) respectively,and the highest concentrations were 10.3,6.4,7.2 and 65.6 mg/kg,respectively.Conclusion The observed level of detection rates and maximum concentrations were relatively high in this survey.In addition,some subgroups of PAEs that were not allowed to use in food contact materials were detected.Therefore,the migration in different food simulant would be analyzed in the next step for further health outcome assessment.

Objective To provide suggestions for the safety management of printing inks and the establishment of food safety standard for food contact materials.Methods The laws,regulations and directives related to printing inks from different countries were collected and the differences among different management models were analyzed and compared.Results The safety management models of European Union,Switzerland,Germany,US and Japan were generalized and their experiences in the management measures of printing inks were summarized.Conclusion Safety standard of printing inks for food contact materials should be established on the basis of industry status and the various safety risks of different inks.Management experiences of other countries should be considered and the participation of industry associations should be encouraged.