Inhibitory effect of zinc on beta-hexosaminidase release from RBL-2H3 cells by synthetic chemicals

The effects of foods and chemicals related to food hygiene on degranulation were evaluated using a method for assaying the enzyme activity of beta-hexosaminidase as an index of chemical mediator release from RBL-2H3 cells in vitro. Using a previously developed assay system, we had found a large number of inhibitors and promoters of degranulation of RBL-2H3 cells. In the present study, we examined the inhibitory effect of zinc chloride on the degranulation (beta-hexosaminidase release) from RBL-2H3 cells with or without antigen in the presence of the degranulation-promotive chemicals, namely, 4 food additives, 7 pesticides and 2 veterinary drugs. These promotive chemicals were classified into two types on the basis of inhibitory profile by zinc chloride: 1) those which showed marked degranulation-inhibitory action when the cells were stimulated with antigen, such as butylhydroxyanisole, dibutylhydroxytoluene, EPN, cis- and trans-permethrin, prothiofos, pyridaben, terbufos, 2) those which showed marked degranulation-inhibitory action whether the cells were stimulated with antigen or not, such as butyl p-hydroxybenzoate, o-phenylphenol, bitertanol, salinomycin. In conclusion, zinc had a dramatic inhibitory effect on enhanced degranulation induced by synthetic chemicals in vitro.     

四乙基硼化钠衍生-气相色谱-串联质谱法测定畜禽肉中有机锡农药残留

建立气相色谱-三重四极杆串联质谱测定畜禽肉中三唑锡、三环锡、三苯基氢氧化锡和苯丁锡的分析方法。样品经1%甲酸-乙腈提取,四乙基硼化钠衍生后用弗罗里硅土固相萃取柱净化,用正己烷-丙酮（99∶1,V/V）洗脱,以HP-5MS毛细管柱分离,采用三重四极杆串联质谱的选择反应监测模式进行分析。同时研究了衍生化产物的一级和二级质谱的裂解途径和机理。结果表明：采用优化条件,三环锡、三苯基氢氧化锡在20～500 μg/L、苯丁锡在20～200 μg/L范围内,线性关系良好,相关系数均在0.997以上,以鸡肉和猪肉为代表性样品基质,在添加0.03 mg/kg和0.10 mg/kg两个水平,方法的平均回收率范围为82.4%～109.6%,相对标准偏差为4.1%～8.9%。三唑（三环锡）、三苯基氢氧化锡和苯丁锡的方法定量限为0.01、0.01 mg/kg和0.02 mg/kg。     

气相色谱-串联质谱同位素内标法测定 果蔬食品中有机锡类农药残留

建立气相色谱-串联质谱同位素内标法测定蔬菜水果中三环锡、三唑锡、薯瘟锡、毒菌锡和苯丁锡等有机锡类农药残留的分析检测方法。样品经过1%冰醋酸-乙腈溶液提取,四乙基硼化钠衍生后用PC/NH_2-SPE固相萃取柱净化,使用正己烷-丙酮(99:1,V/V)洗脱,采用EI源进行测定。结果表明,在0.05～1.00 mg/L质量浓度范围内,3种有机锡类农药呈良好线性,相关系数均在0.998以上,在0.04、0.10、0.20 mg/kg三个添加水平下,阴性样品中有机锡的回收率范围在81.64%～106.23%,相对标准偏差(RSD)均小于6.33%(n=6)。三环锡、薯瘟锡和苯丁锡的方法定量限分别为0.01、0.009和0.039 mg/kg。该方法稳定可靠,灵敏度高,可用于水果蔬菜等农产品中有机锡类农药的测定,并对其他食品中有机锡类农药的测定方法提供了参考依据。     

Effects of veterinary drugs on beta-hexosaminidase release from rat basophilic leukemia cells (RBL-2H3)

Little is known about the effects of residual veterinary drugs on the allergic reaction, except for the antigenicity of antibiotics and synthetic antimicrobials. Therefore, 59 kinds of veterinary drugs were investigated for their effects on the IgE receptor-mediated beta-hexosaminidase release from RBL-2H3 cells as an index of immediate allergic reaction. We found that the antibiotics chlorotetracycline, doxycycline, monensin, the synthetic antimicrobial pyrimethamine and the steroid hormone testosterone inhibited beta-hexosaminidase release. Most of the veterinary drugs showed no action, though the ionophores lasalocid, salinomycin and the steroid hormone hexestrol promoted beta-hexosaminidase release from injured cells. Based on the residual levels of these drugs and the frequencies of detection in actual food samples, it seems unlikely that these drugs have any immediate allergic effect in practice.     

Method-performance studies of notified analytical method for fenbutatin oxide and cyhexatin

Method-performance studies were conducted for the notified revised analytical method of fenbutatin oxide (FBTO) and cyhexatin (CHT). FBTO and CHT spiked into rice, soybeans, spinach, orange, tea powder and tea extract at the level of 0.5 microgram/g for FBTO and 0.1 microgram/g for CHT were analyzed in replicate in 6 laboratories. Means recoveries of FBTO were 85.2-96.5% and those of CHT were 83.5-89.2% except from soybeans (46.5%). Repeatability relative standard deviation values of FBTO and CHT in each crop were in the ranges of 2.3-9.4% and 3.2-6.3%, respectively. Reproducibility relative standard deviations were 3.9-12.6% for FBTO and 8.3-12.9% for CHT. Detection limits were 0.015-0.05 microgram/g for FBTO and 0.005-0.02 microgram/g for CHT.     

新疆红枣农药残留风险评估与排序

为明确残留农药对新疆红枣质量安全的危害水平及其排序,本文以新疆10县市产出的124份红枣样品为研究对象,并对37种农药残留进行了测定,在此基础上,通过急性、慢性膳食摄入风险分析,探讨了残留农药对红枣质量安全的危害水平;并采用风险矩阵,对残留农药进行了风险排序。结果显示,样品中残留11种农药;残留农药的% ADI(慢性膳食摄入风险)值远小于100%;10种农药的% ARfD值(急性膳食摄入风险)也远低于100%;较其他残留农药,哒螨灵、毒死蜱、苯醚甲环唑、氯氟氰菊酯、氯氰菊酯、甲氰菊酯6种残留农药风险值相对较高,均大于12.05。结论:新疆红枣残留农药的膳食风险较低,哒螨灵、毒死蜱、苯醚甲环唑、氯氟氰菊酯、氯氰菊酯、甲氰菊酯为需重点关注的农药。     

Germin-like protein Cit s 1 and profilin Cit s 2 are major allergens in orange (Citrus sinensis) fruits

Oranges are clinically relevant allergenic foods. To date, orange allergens have not been characterized in detail. The study is aimed at analyzing the sensitization profile in orange-sensitized subjects with and without clinical allergy, and to identify orange allergens. Fifty-six sensitized subjects with self-reported reactions to orange were grouped into reactors (anaphylaxis or multiple episodes of immediate reactions and/or positive challenge tests) and non-reactors (negative open food challenge tests). Allergens were characterized by IgE immunoblotting, N-terminal sequencing, IgE-inhibition assays, and mediator release assays were performed to determine the allergenic potency of orange profilin. Of 56 subjects, 23 were classified as orange allergic showing mainly an oral allergy syndrome. Of 23 subjects classified as orange allergic, 22 were sensitized to profilin, Cit s 2. In patients with mono-sensitization to profilin in vitro histamine releases up to 75% from basophils were induced using orange extract and purified plant profilins. Of the allergic patients 78% were sensitized to germin-like protein, Cit s 1. Both allergens showed retained IgE reactivity in heat-processed orange juice. Interestingly, subjects with and without clinical allergy showed a comparable sensitization profile. Profilin and germin-like proteins are major orange allergens. The potential clinical relevance of orange profilin was indicated by its strong capacity to release histamine from basophils. However, a predominant sensitization to both allergens in subjects without symptoms also indicates a high frequency of clinically insignificant sensitization.     

Multiresidue determination of pesticides in honey samples by gas chromatography–mass spectrometry and application in environmental contamination

A simple and fast multiresidue method has been developed to determine 48 pesticides within the major groups of pesticides (organohalogen, organophosphorous, pyrethroids and organonitrogen) in representative samples of locally produced honey, in Bauru (State of São Paulo, Brazil) during 2003–2004. The recovery results found ranged from 76% to 95% and the limits of detection were lower than 0.01 mg/kg for gas chromatography with electron impact mass spectrometric detection in the selected ion monitoring mode (GC–MS-SIM). The results indicated that most pesticides found in the samples belonged to the organohalogen and organophosphorous groups and lower levels of residues of some organonitrogen and pyretroids were also detected. Malathion residues were detected in all the samples, in a high concentration, owing to its applications to control dengue mosquitoes in the area studied.     

Survey of pesticide residues in rice (April, 1995-March, 2005)

Pesictide residues in 343 samples of domestic rice and 32 samples of imported rice purchased on the Tokyo market from April 1995 to March 2005 were investigated. Residues of eleven kinds of pesticides (including organophosphorus, organochlorine, carbamate, pyrethroid and organonitrogen pesticides and bromide) were detected at levels between trace and 1 ppm in 47 domestic rice samples. DDVP and bromide residues were detected at levels between 0.01 ppm and 5 ppm in 18 imported rice samples. For rice samples that were found to containing pesticides, the amounts of pesticide intake were calculated according to the daily intake of rice, and they were compared with the ADI values. Since residual pesticide levels were 17/10,000-2/5 of ADI, all the rice samples were considered to be safe for human consumption.     

苹果汁中三唑锡和三环锡残留量的检测方法

建立了苹果汁中三唑锡和三环锡残留量的气相色谱和气相色谱-质谱分析方法。果汁中三唑锡和三环锡用正己烷提取后,经四乙基硼化钠进行衍生化,用气相色谱法和气质联用法测定衍生化产物;在苹果汁空白添加浓度为0.02～0.08mg/kg范围内,平均回收率为80%～90%,相对标准偏差4.1%～8.9%,定量限0.01mg/kg。讨论了衍生化产物的质谱特征,选择特征离子m/z233、315、203和287。     

超高效液相色谱-串联质谱结合QuEChERS方法快速检测柑橘中的残留苯丁锡

采用改进的QuEChERS方法结合超高效液相色谱-串联四极杆质谱仪,建立快速检测柑橘中残留苯丁锡的方法。样品经乙腈提取、无水MgSO4和NaCl脱水盐析、十八烷基硅胶键合相分散萃取净化,采用BEH C18液相色谱柱分离（2.1 mm×50 mm）,等度洗脱,在多反应监测模式下测定,基质匹配标准溶液外标法定量。结果表明：在0.001～1.0 mg/L范围内,苯丁锡含量与峰面积具有良好的线性关系,R2≥0.993 0;方法定量限为2.0 μg/kg;在方法线性范围内,柑橘果肉、果皮和全果中低、中、高3 个添加水平的平均回收率为74.0%～97.7%,相对标准偏差为2.5%～6.9%。该方法操作简单、快速、成本低、环境友好、安全、精确度高,能满足柑橘中痕量苯丁锡残留的快速确证和定量检测要求。     

餐前加工对辣椒中5种常见农药残留去除的影响

通过研究清洗及烹饪过程对辣椒中百菌清、哒螨灵、腐霉利、氯氟氰菊酯及氰戊菊酯残留的影响,了解农药在加工过程中的变化规律,为膳食暴露评估提供依据。方法 采用实验室浸泡法模拟农药污染试验,并模拟家庭日常加工对辣椒进行清洗、烹饪等处理,通过气相色谱法(ECD)检测加工前后辣椒中农药残留变化。结果 清洗及烹饪对农药残留均有明显影响,以上5种农药在辣椒中经清洗和烹饪后总去除率分别为54.12%～99.47%、58.78%～95.95%、55.74%～93.68%、41.37%～95.67%和44.71%～95.09%;不同烹饪方法对农药的去除作用由强到弱为:油炸>炒制>焯水,且烹饪时间越长,去除作用越大,当烹饪时间超过2 min后,去除作用则不发生明显变化。结论 烹饪对辣椒中农药残留的去除作用比清洗时好,加工对农药的影响受农药的水解、高温分解特性、熔沸点及饱和蒸汽压等性质的共同作用决定。     

甜瓜MRLs增补种类及其建议值分析

为明确甜瓜最大残留限量值增补种类及其建议值,本文以2018和2019年6个省份545份甜瓜为实验材料,在完成实验材料中60种农药残留定量分析的基础上,通过急性膳食风险分析（%ADI）、慢性膳食风险分析（%ARfD）、风险矩阵等技术方法,探讨了甜瓜残留农药的质量安全风险,开展了风险相对较高残留农药及最大残留限量值（MRLs）增补种类及其建议值的研究与分析,结果显示:残留农药急、慢性膳食风险均低于100%,二甲戊灵的急性膳食风险相对较高,达到56.67%;残留农药中,哒螨灵、甲维盐、联苯菊酯的残留风险相对较高;65.22%的残留农药无最大残留限量,其中包括3种风险相对较高的残留农药。综合以上分析可知:哒螨灵、甲维盐、联苯菊酯、二甲戊灵兼具风险相对较高和无最大残留限量的特点,建议制订对应限量值,建议值依次为:1、0.05、1、3 mg·kg?1。     

6种杀虫剂在上海青中的残留消解动态及膳食风险评估

目的评价蔬菜生产中6种常用杀虫剂5%啶虫脒乳油、15%哒螨灵水乳剂、20%溴氰虫酰胺可分散油悬浮剂、30%唑虫酰胺悬浮剂、22%氟啶虫胺腈悬浮剂和60g/L乙基多杀菌素悬浮剂在十字花科蔬菜上海青中的残留消解动态,评估其膳食摄入风险。方法于2018年4~10月在福州采用喷雾的施药方法进行了6种药剂在上海青上的残留试验,通过超高效液相-串联质谱法(ultra performance liquid chromatography-tandem mass spectrometry, UPLC-MS/MS)检测6种药剂在上海青中的残留量,并对6种药剂可能产生的膳食摄入风险进行评估。结果 6种杀虫剂在上海青中的回收率在90.8%~99.6%,相对标准偏差(relative standard deviation,RSD)在1.1%~3.7%;啶虫脒、哒螨灵、溴氰虫酰胺、唑虫酰胺、氟啶虫胺腈、乙基多杀菌素在上海青中的降解半衰期为分别为3.6、6.2、3.6、4.6、1.7和2.9 d。用药后1~14 d,啶虫脒、哒螨灵、溴氰虫酰胺和乙基多杀菌素在上海青中的残留量均分别低于其定量限;唑虫酰胺和氟啶虫胺腈在上海青中的最高残留量分别为0.5136 mg/kg和1.4488 mg/kg;6种药剂在上海青中残留的风险商值(risk quotient, RQ)均<1。结论 6种药剂在上海青中的最终残留均低于我国在《食品中农药最大残留限量》中规定的其在蔬菜(叶菜类)中最高残留限量(maximum residue limits, MRLs), 6种药剂的膳食暴露风险较低,残留处于安全水平。     

Determination of captafol,cyhexatin, 1-naphthylacetic acid and quintozene in apple,Japanese pear and melon by simultaneous extraction

A simple and rapid method is described for the determination of the non-registered pesticides, captafol, quintozene (PCNB), cyhexatin and 1-naphthylacetic acid (NAA), in fruits. These pesticides were extracted with acidified acetone, then captafol and PCNB were purified with a Florisil mini column and analyzed by GC-ECD. Cyhexatin was ethylated with ethylmagnesium bromide, and the ethyl derivative was analyzed by GC-FPD (Sn filter). NAA was purified with liquid-liquid extraction and determined by HPLC equipped with a fluorescence detector. These analytes were identified with GC/MS or LC/MS. The minimum identified concentration of the pesticides was below 0.2 ng per injection, which corresponds to a detection limit of below 0.02 microgram/g in the original samples. Recoveries of the pesticides spiked at 0.1 microgram/g into apple, Japanese pear and melon were greater than 61%.     

The effectiveness of some recently developed pesticides against stored-product mites

Ten recently developed pesticides have been tested against Tyrophagus longior, T. putrescentiae, and susceptible and HCH-resistant strains of both Acarus siro and Glycyphagus destructor. They were applied as dusts or emulsion concentrates to wheat and the mortality of added mites was evaluated 2 weeks later. Etrimfos at 20 ppm and profenofos at 10 ppm killed all mites of all strains. Propargite at 20 ppm killed all strains except HCH-resistant A. siro, whereas methacrifos at 4 ppm killed all except HCH-susceptible A. siro. Heptenophos at 2 ppm controlled susceptible and resistant strains of G. destructor. ‘Cycloprate’ at 200 ppm, and U42662, ‘isoprothiolane’, fenbutatin oxide and ‘xymiazol’, all at 20 ppm, failed to give complete mortality of any strain. Several compounds reputedly effective against plant-feeding mites or ticks were ineffective against the storage mites tested.     

粮食中高毒有机氮类农药的HPLC法测定

建立了高效液相色谱法（HPLC）测定粮食中高毒有机氮类农药春威、叶蝉散、仲丁威、灭虫威、西维因、杀虫威的方法。结果表明,该方法线性范围为0．02～5．00mg／L,相关系数为0．9972～0．9998,检出限为0．0256～2．320mg／kg,加标回收率为78．66％～103．23％,相对标准偏差为2．5～5．1。     

Investigation of pesticide residues in vegetables and fruits grown in various regions of Hatay,Turkey

In this study, 175 pesticide residues in various vegetable and fruit samples grown in different regions of Hatay, Turkey, were investigated. Residue analyses were performed using liquid chromatography–tandem mass spectrometry with the QuEChERS method. In tomato, plum and apricot samples, pesticide residues were below the limits of detection. In other samples, at least one pesticide residue was detected. Twelve pesticides (acetamiprid, carbendazim, chlorpyrifos, fenarimol, fludioxonil, hexythiazox, imidacloprid, metalaxyl, pyridaben, pyriproxyfen, thiabendozole, triadimenol) were found at levels between 0.003 and 0.759?mg?kg^?1. Only in cucumber samples, acetamiprid residues were found at levels greater than the maximum acceptable limit in Turkish Food Codex and European Union maximum residue limits (EU MRLs). In other samples, the detected residue amounts are less than the MRLs declared in the Turkish Food Codex and EU MRLs.     

Finding of pesticides in fashionable fruit juices by LC–MS/MS and GC–MS/MS

Products labelled as containing extracts from two mushrooms (cordyceps plus reishi) and the juices from açaí, goji, mangosteen, noni, pomegranate, and sea buckthorn have been analysed for 174 different pesticides, using the validated QuEChERS method for sample preparation and electrospray LC–MS/MS in the positive ion mode for analysis. Pesticides were found in 10 of the 21 samples analysed. Most pesticides found were below the tolerance levels (1–6 μg/g, depending on the pesticide), but some were not. This included boscalid, dimethomorph, iprovalicarb, pyridaben, pyrimethanil, and imazalil, for which there is no tolerance reported or zero tolerance in any fruit. However, genuine açaí that was harvested in the state of Pará and lyophilised in Rio de Janeiro had no detectable pesticides, when analysed by both LC–MS/MS and GC–MS/MS, which can detect 213 more pesticides and industrial chemicals. Likewise no pesticides were found in one sample each of cordyceps plus reishi, sea buckthorn and noni.     

Effect of household and industrial processing on the levels of pesticide residues and degradation products in melons

Two varieties of melons (Cucumis melo) were treated with two fungicides (carbendazim and maneb) and four insecticides (acetamiprid, cyromazin, imazalil and thiamethoxam) to quantify the effect of household processing on the pesticide residues. To ensure sufficiently high levels of residues in flesh and peel, the most concentrated formulations were applied observing good agricultural practice. The peeling step decreased the concentration of pesticide residues for maneb, imazalil and acetamiprid by more than 90%. Cyromazin, carbendazim and thiamethoxam were reduced by approximately 50%. The reduction of the pesticides could not be fully explained by the systemic character of the pesticides. However, the agricultural practices (time of application), solubility and mode of action (systemic versus contact pesticide) of the pesticides could be used to explain the difference in processing factors for the studied pesticides. Degradation products (melamine and ethylenethiourea) were also investigated in this study, but were not detected.