甘肃省3个非暴露地区居民母乳中二噁英负荷水平与影响因素分析

摘要：目的 调查甘肃省非暴露地区母乳中二噁英类化合物污染水平，分析影响当地人群二噁英类化合物污染的相关因素。方法 在甘肃省城区、近郊区和远郊区3个采样点各采集50份顺产初产妇产后第3-8周的母乳样品，以高分辨气相色谱-高分辨质谱分析仪分析样品中多氯代苯并二噁英和多氯代苯并呋喃(PCDD/Fs)和多氯联苯(PCBs)含量，计算总毒性当量浓度（TEQ）。结果 （1）PCDD/Fs和 dl-PCBs在甘肃省母乳样品中普遍存在，dl-PCBs含量远高于PCDD/Fs，但按TEQ计时，PCDD/Fs贡献高于dl-PCBs；（2）甘肃省PCDD/Fs组分含量最高的OCDD，含量在102.08~195.18?pg/g脂肪之间，来源可能与垃圾焚烧导致污染有关；母乳中PCBs污染分布呈现出城市点（2436.88 pg/g）>近郊区（1118.16?pg/g）>远郊区（989.87?pg/g）的特征，可能与居民肉蛋奶等动物性食品摄入频次较高有关。结论 甘肃省非暴露区母乳中二噁英类化合物含量均低于全国水平，总体上城市高于农村，但个别同系物数值农村点与城市点接近甚至高于城市点，这提示甘肃省不同地区人体暴露情况有其独特性和复杂性。     

杭州市售食品中持久性有机污染物膳食暴露评估

目的调查杭州市售食品中持久性有机污染物(persistent organic pollutants,POPs)的水平,进行初步膳食暴露评估,为风险评估和膳食指导提供依据。方法采集杭州地区鱼油、猪肉、牛奶、婴儿奶粉、乳粉、鸡蛋、猪肝共7种50份样品,采用气相色谱仪-高分辨质谱法(gas chromatograph-high resolution mass spectrometry,GC-HRMS)分析POPs浓度。结果被检测的食物中,二噁英、多氯联苯含量最高的分别是猪肝、鱼油;二噁英、多氯联苯毒性当量最高均为猪肝,鸡蛋和猪肉的毒性当量高于其他地区报道数据。结论 18岁以下低年龄段暴露风险高于18岁以上的高年龄段,城市居民暴露量高于农村居民。     

酶联免疫法快速检测大闸蟹中二噁英污染物的研究

目的建立大闸蟹中二噁英的酶联免疫(enzyme linked immunosorbent assay, ELISA)检测方法。方法优化加速溶剂萃取条件,净化过程及前处理方法。样品取可食部分冷冻干燥,经加速溶剂萃取方法提取,酸性硅胶处理,过复合硅胶柱、活性碳小柱配合加压设备加速净化,酶联免疫试剂盒检测。结果二噁英标准品在3.2、25.0、50.0、100.0 pg/5 g干重毒性当量(World health organisation-toxic equivalent, WHO-TEQ)值添加水平的回收率为68.2%～123.1%,相对标准偏差小于30%(n=6),线性相关性(r2)一般大于0.98。样品检测值均低于1.5 WHO-TEQ pg/g湿重的欧盟标准。结论该方法方便、快速、成本低,适用于大闸蟹中二噁英基础定量检测。     

我国部分地区猪肉、猪肝二噁英污染状况与风险评估

目的 分析来自A、B、C、D、E五省猪肉、猪肝二噁英污染状况,并针对人群膳食暴露量进行评价,为未来制定国家食品安全二噁英限量标准提供基础数据。方法 于2013年至2019年共采集146份猪肉和猪肝样品,参照国家标准方法《食品中二噁英及其类似物毒性当量的测定》（GB 5009.205—2013）,采用同位素稀释的高分辨气相色谱/高分辨双聚焦磁式质谱联用（HRGC/HRMS）技术,对样品中的17种二噁英单体进行准确定量分析检测。根据食物消费量数据,采用点评估方法进行人群膳食暴露量评估。结果 猪肉和猪肝样品中二噁英毒性当量浓度中位数分别是0.106、2.32 pg/g·fat;各地区猪肉二噁英浓度水平以A （0.859 pg/g·fat）>D（0.145 pg/g·fat）>C（0.097 4 pg/g·fat）>B（0.039 9 pg/g·fat）>E（0.023 pg/g·fat）依次降低,猪肝二噁英的浓度水平以A （3.616 pg/g·fat）>B （1.84 pg/g·fat）>D（1.313 pg/g·fat）>E（0.85 pg/g·fat）依次降低。猪肉和猪肝样品中PCDD/Fs的质量浓度单体分布特征相似,均以OCDD为主要优势单体,分别占95%、90%,但猪肉和猪肝TEQ浓度单体分布特征存在差异;不同地区同一类别样品的二噁英单体特征也存在较大差异。五个地区居民通过食用猪肉每月摄入的PCDD/Fs为0.192~2.054 pg/kg·bw/m,低于粮农组织/世界卫生组织食品添加剂联合专家委员会（ Joint FAO/WHO Expert Committeeon Food Additives, JECFA）规定的70 pg/kg·bw/m的暂定每月容许摄入量（Provisional tolerable monthly intake, PTMI ）。结论 我国部分地区市售猪肉及猪肝样品存在一定程度的二噁英污染;经济发达地区猪肉、猪肝样品中二噁英的浓度水平较高,存在明显的空间差异;总体来看居民经猪肉摄入的二噁英暴露风险较小。下一步应持续开展重点食品中二噁英污染水平的监测工作,并针对高暴露地区人群开展二噁英及其类似物的总膳食暴露评估,以更好地保障畜肉类食品安全和人体健康。     

基于主成分分析和聚类分析评价中华绒螯蟹蟹肉香气品质的研究

运用顶空固相微萃取-气-质联用技术,对采自阳澄湖的特级、1级、2级的雌性中华绒螯蟹体肉、钳肉和足肉中的香气成分进行了鉴定并以内标法对其定量。通过主成分分析法(PCA)和聚类分析法(CA)对不同蟹肉样品的香气品质进行评价。主成分分析结果显示:不同等级中华绒螯蟹钳肉和足肉的综合得分均大于零(2级-钳肉除外),香气品质较好,醇类、酮类、呋喃类、含氮类和芳香类五类成分对其贡献显著,是表征"高品质风味"的特征性香气成分;将部位因素统一考虑后,大闸蟹等级越高,蟹肉香气品质越好;将等级因素统一考虑后,大闸蟹足肉香气品质最佳,钳肉次之,体肉最差。经聚类分析发现:不同等级大闸蟹体肉及足肉样品香气轮廓可各自聚为一类。醇类、呋喃类、酮类、含氮类和芳香类5类香气成分可聚为一类。主成分分析和聚类分析结果存在一致性且可以相互补充,今后可利用两种方法建立不同大闸蟹蟹肉香气品质的评价模型。     

同位素稀释高分辨气相色谱-高分辨磁质谱法测定大闸蟹中二噁英及其类似物

建立了同位素稀释高分辨气相色谱-高分辨磁质谱法测定大闸蟹中二噁英类化合物及二噁英类多氯联苯。对大闸蟹的白肉及棕肉分别进行测定,样品经加速溶剂萃取(丙酮-正己烷-二氯甲烷：20:40:40,体积比)、酸化硅胶初步净化、全自动二噁英净化系统净化后,分别收集PCDD/ Fs、DL-PCBs的净化液,浓缩后上机分析。采用选择离子监测模式进行测定,白肉PCDD/ Fs的检出限在0.016ng/kg~0.106 ng/kg范围内,DL-PCBs的检出限在0.105 ng/kg~0.252 ng/kg范围内;棕肉PCDD/ Fs的检出限在0.053 ng/kg ~0.353 ng/kg范围内,DL-PCBs的检出限在0.120 ng/kg~0.840 ng/kg范围内。大闸蟹白肉PCDD/ Fs、DL-PCBs的同位素定量内标溶液的平均回收率分别为73.4%~103.5%、74.8%~93.0%;RSD分别为6.4%~21.5%、10.5%~24.7%;大闸蟹棕肉PCDD/ Fs、DL-PCBs的同位素定量内标溶液的平均回收率分别为59.8%~90.1%、65.7%~92.1%;RSD分别为7.5%~23.5%、7.5%~24.8%。本文建立的方法灵敏度高,干扰小,能完全满足国内外的检测需要。     

中华绒螯蟹蟹肉和蟹黄中挥发性风味物质组成

采用同时蒸馏萃取技术(SDE)方法提取中华绒螯蟹中的挥发性风味成分,利用气相色谱-质谱联用技术(GS-MS)对提取的中华绒螯蟹蟹肉和蟹黄中挥发性风味成分进行分离鉴定。结果表明：在中华绒螯蟹中共检测到97种挥发性化合物。其中,蟹肉和蟹黄中含有的挥发性化合物的数量分别为60种和67种,仅有30种挥发性化合物被检测到同时存在于蟹黄和蟹肉中;中华绒螯蟹蟹黄和蟹肉中的挥发性成分在组成上的差别主要体现为在醇类、芳香类、烷烃类和含硫类化合物的组成上,这可能是导致中华绒螯蟹蟹黄和蟹肉香气差异的主要原因;除了组成上的差异,蟹黄中检测到的挥发性化合物的含量普遍高于蟹肉中检测到的化合物的含量。     

不同育肥方式对中华绒螯蟹雄蟹肌肉呈味物质的影响

本文采用高效液相色谱仪、氨基酸自动分析仪、石墨炉原子吸收光谱仪等测定了配合饲料和野杂鱼育肥的中华绒螯蟹雄蟹肌肉中非挥发性呈味物质,包括游离氨基酸,呈味核苷酸和呈味无机离子,并且采用味道强度值和味精当量对这些成分的呈味强度进行评价。FD蟹肉中游离氨基酸总量稍高于TF蟹肉(二者分别为2270、2016 mg/100 g),两种蟹肉中呈味氨基酸含量均占总量的68%,对FD和TF蟹肉滋味均有贡献。FD和TF蟹肉中的呈味核苷酸含量较低,TAV值小于1,对蟹肉滋味没有直接贡献,但可与其他成分产生协同作用,增强蟹肉滋味。无机离子中K+、PO3+4和Ca2+对TF蟹肉有直接贡献,而对FD蟹肉有直接贡献的是K+和PO3+4。结果表明TF蟹肌肉EUC值是1.61 g MSG/100 g,FD蟹肌肉EUC值是是2.50 g MSG/100 g,味精当量的TAV值是53.7和83.3,鲜味强烈,并且FD蟹肉鲜味显著(p=0.01)优于TF蟹肌肉。     

大闸蟹 品蟹的最高享受

正在过去,真正有条件、讲究饮食文化的人家儿,吃螃蟹是件极其隆重的事情。首先,要在自家四合院里,花厅之中设置桌椅;其次,厅外要有绽放的菊花;当然家里还要备有全套的食蟹工具。斟上陈年花雕,一笼肥蟹端上来,饮酒、品蟹、赏花、吟诗,这种品味、这种意境,似乎才是吃螃蟹的最高享受吧。选蟹:阳澄湖大闸蟹说到哪儿的大闸蟹最好,众说纷纭。但如果问哪儿的大闸蟹最出名,那非阳澄湖大闸蟹莫属。阳澄湖因蟹而闻名,总面积为120平方公里的宽阔水面,有着纯天然的上好水质,适合多种水生物生长。"大闸蟹"是阳澄湖中所产螃蟹的专有名词,清水大闸蟹素有"蟹中之王"的美称。其蟹体结实、蟹肉鲜美、     

自动样品净化系统分析鱼样中二噁英和共平面多氯联苯

为评价自动样品净化系统在分析食品样品中17种二噁英(PCDD／Fs)与12种共平面多氯联苯(PCBs)上的应用，以鱼样有证标准参考物对系统进行验证。鱼肉标准参考物质经索式抽提、FMS Power Prep系统净化后浓缩，使用高分辨气相色谱-高分辨质谱联用仪以多离子检测方式和同位素稀释技术对样品中的目标化合物进行定性和定量。样品中PCDDs／Fs同位素内标的平均回收率为62.4％～84．3％，共平面PCBs同位素内标的平均回收率为53．1％～89．2％。3个不同浓度水平的有证标准参考物的TEQ测定值均与参考值符合。FMS Power Prep样品净化系统可以满足食品样品中PCDD／Fs和共平面PCBs的分析要求。     

Dioxin-like polychlorinated biphenyls in marine fish from Shandong,China, and human dietary exposure

The occurrence and human dietary exposure of 12 dioxin-like polychlorinated biphenyls (DL-PCBs) in 41 marine fish samples from Shandong Province of China were investigated. The DL-PCB congeners were extracted using automated Soxhlet extraction, purified via a composite column clean-up procedure and analysed by gas chromatography-triple quadrupole mass spectrometry. DL-PCB congeners were found in all analysed samples, with a mean concentration of 0.887 ng/g ww (wet weight). The TEQ concentrations of DL-PCBs in individual fish samples ranged from 0.011 to 9.214 pg WHO TEQ/g ww. The mean dietary intake for all fish species was 36.5 pg TEQ/kg bw/month, which was lower than the provisional tolerable monthly intake of 70 pg TEQ/kg bw/month set by the Joint FAO/WHO Expert Committee on Food Additives. To monitor the trend of DL-PCBs in fish for food safety control, it is necessary to maintain a surveillance programme.     

Carry-over of dioxins and PCBs from feed and soil to eggs at low contamination levels - influence of mycotoxin binders on the carry-over from feed to eggs

Laying hens were fed with compound feed containing six different levels of dioxins, dioxin-like PCBs and indicator PCBs for a period of 56 days. This was followed by a period of 56 days on clean feed. Dioxin levels in feed varied from background levels to three times the current EU tolerance limit of 0.75 ng TEQ/kg. At all dose levels a rapid increase was observed in the dioxin levels in eggs. There was a clear linear dose-response relationship between the dioxin levels in eggs and feed. The feed containing 0.4 ng TEQ dioxins per kg resulted in egg levels just above the EU limit of 3 pg TEQ/g fat. Dioxin-like and indicator PCB residues followed a pattern very similar to that of dioxins. Exposure to the highest indicator PCB level of 32 µg/kg resulted in egg levels around 300 ng/g fat. Exposure to dioxins through contaminated soil, mixed at 10% into the feed, resulted in a similar carry-over as from feed. Mycotoxin binders, mixed at 0.5% into the feed, had little effect on the carry-over of dioxins from the feed to the egg. It can be concluded that consumption of feed or soil with even moderate levels of dioxins and dioxin-like PCBs rapidly results in increased levels in eggs. The current EU dioxin limit for feed cannot guarantee egg dioxin levels below the EU-limit.     

Polychlorinated dioxins, furans, and biphenyls, and polybrominated diphenyl ethers in a U.S. meat market basket and estimates of dietary intake

Persistent environmental contaminants including polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), non-ortho-polychlorinated biphenyls (PCBs), and polybrominated diphenyl ethers (PBDEs) were analyzed in 65 meat samples collected from supermarkets across the U.S. in 2001. The samples included hamburger, sirloin steaks, pork chops, bacon, and whole chickens from nine different cities. The average PCDD/F/non-ortho-PCB toxic equivalency (TEQ) for all the samples was 0.55 pg/g of lipid (nd (nondetect) = DL (detection limit)/2) with a range from nondetectable to 3.21 pg/g of lipid. For PBDEs, eight congeners were routinely found in the meat samples with an average sum of 1.71 ng/g of lipid (nd = DL/2) and a range from nondetectable to 16.6 ng/g of lipid. While average TEQs were similar to recent values reported in Europe and Asia, the sums of PBDEs in chicken and pork were 3-20 times higher than levels reported in Spain and Japan for these foods. The presence of a few outliers raised the average PBDE sums and indicated that isolated sources of contamination may exist that, if identified, could be removed from the U.S. animal production chain. Using these TEQ and PBDE values and USDA food consumption data, the estimated dietary intake ranges from meat products were 5.3-16.0 pg TEQ and 14.9-44.7 ng of PBDEs/d or 0.1-0.3 pg TEQ and 0.3-0.5 (ng of PBDEs/kg of body mass)/d for an average individual, similar to intakes in other countries.     

婴儿配方乳粉中二噁英及其类似物污染分析

目的 了解婴儿配方乳粉中二噁英及其类似物污染水平,为相关研究提供基础数据.方法 采集601份市售婴儿配方乳粉,按照GB 5009.205-2013《食品安全国家标准食品中二噁英及其类似物毒性当量的测定》对17种多氯代苯并二噁英和多氯代苯并呋喃(PCDD/Fs)和12种二噁英样多氯联苯(dl-PCBs)进行测定.结果 P...     

The use of the DR CALUX bioassay and indicator polychlorinated biphenyls for screening of elevated levels of dioxins and dioxin-like polychlorinated biphenyls in eel

The DR CALUX bioassay is a very suitable screening method for dioxins and dioxin-like-PCBs in feed and food. This was, e. g. demonstrated in a survey in the Netherlands to control the dioxin levels in eel. The DR CALUX assay, but also indicator polychlorinated biphenyls (PCB) were evaluated as a screening method. Based on the limit for polychlorinated dibenzo-p-dioxins/dibenzofurans (PCDD/F) [at that time 8 pg toxic equivalents (TEQ)/g eel], and the relation between PCDD/F and dioxin-like-PCB, a decision limit of 30 pg TEQ/g eel was used for screening of 153 field samples. Suspected samples (21) and part of the higher contaminated negative samples (35) were analyzed by GC/MS for dioxins, non-ortho, mono-ortho and indicator PCB, revealing 13 samples exceeding the action limit of 30 pg TEQ/g eel. Only one sample slightly exceeded the dioxin level of 8 pg TEQ/g eel. The relatively low sensitivity for mono-ortho PCB was overcome by the use of reference samples, as shown by the correlation of 0.93 between GC/MS and CALUX determined total TEQ levels. The present data show that the DR CALUX assay can be used for screening of total TEQ levels in eel. The use for dioxins only requires a safe, and therefore relatively low, decision limit. The indicator PCB also showed a good correlation with total TEQ levels, mainly due to the large contribution of the mono-ortho PCB at higher concentrations. The relation with dioxins was very poor and as such indicator PCB seem less suitable than the DR CALUX assay for screening for dioxins only. The present study clearly shows that part of the wild eel samples contains high total TEQ levels and will exceed the future European Union limit of 12 pg TEQ/g eel for dioxins and dioxin-like PCB. Especially at high TEQ levels, dioxin-like PCB contribute most to the total TEQ. In practice, wild eel presents only a minor part of the eel consumed.     

鱼肉粉中二噁英及二噁英类多氯联苯成分分析标准物质的研制

目的 研制鱼肉粉基体中二噁英及二噁英类多氯联苯成分分析标准物质。方法 以草鱼为原料,采用污染物含量较高的飞灰样品配合饲料喂养,经去骨去皮,匀浆干燥、研磨筛分等过程后制得候选标准物质,经均匀性和稳定性评价,由8家实验室定值,分析评估其不确定度。结果 经检验基体标准物质均匀性良好,能长期稳定保存至少12个月,PCDD/Fs的特性值为0.017～1.4 pg/g,扩展不确定度为0.02～0.6 pg/g;DL-PCBs的特性值为0.54～16 pg/g,扩展不确定度为0.28～6 pg/g。此标准物质已通过标准物质评审,编号为GBW(E)100741。结论 该标准物质均匀性及稳定性良好,定值准确,可用于食品、环境等领域二噁英及二噁英类多氯联苯的量值溯源、分析检测、质量控制、实验室能力验证、分析仪器校准、分析方法的准确性评估和验证等。     

Dietary intake of dioxins in Japan in 2016 with time trends since 1998

Total diet samples collected from seven regions throughout Japan in 2016 were analysed for polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans and dioxin-like polychlorinated biphenyls (DL-PCBs), known collectively as dioxins. This led to estimates of the latest dietary intake of these contaminants for the general Japanese population (≥1 year old). The average daily intake of dioxins for a person weighing 50 kg, calculated at non-detected congener concentrations assumed to be equal to zero, was estimated to be 0.54 pg TEQ (toxic equivalents) kg^?1 body weight (bw) day^?1. This value is well below the tolerable daily intake of 4 pg TEQ kg^?1 bw day^?1 for dioxins in Japan. The average intake was highest from fish and shellfish, followed by meat and eggs. The TEQ contribution of the fish and shellfish group to the total dietary TEQs was significant (89%). The DL-PCBs accounted for about 67% of the dioxin intake. The latest dioxin intake level was compared with previous estimates from total diet study results obtained annually since 1998 to determine the time trends in the dietary intake of dioxins in Japan. Overall, the average dioxin intake appeared to be decreasing gradually during the period of study. The previous average intakes of dioxins ranged from 0.58 to 1.9 pg TEQ kg^?1 bw day^?1. The latest average intake was the lowest since 1998 and was about one-third of the average intake in 1998. This decreasing trend in the dietary intake of dioxins was mainly influenced by the decreased dioxin intakes from two food groups, fish and shellfish, and meat and eggs.     

我国沿海主要海域雌性三疣梭子蟹呈味成分含量的比较

以我国渤海、黄海、东海和南海4个海域中雌性三疣梭子蟹的肝胰腺、性腺和体肉为研究对象,采用电子舌、氨基酸自动分析法以及高效液相色谱法研究不同海域的生长环境对雌性三疣梭子蟹3个可食部位游离氨基酸含量和呈味核苷酸化合物的变化,并采用滋味强度值和味精当量对呈味成分的强度进行评价。结果表明:电子舌可对4个海域中雌性三疣梭子蟹的肝胰腺、性腺和体肉进行有效区分;在肝胰腺部分,游离氨基酸总量是3个可食部位最高的,3种呈味核苷酸中肌苷酸和腺苷酸的含量较高;在不同海域中,渤海肝胰腺组游离氨基酸总量最高,为3 315.05 mg/100 g,且其味精当量值最高,为15.87 g MSG/100 g;南海肝胰腺组游离氨基酸总量最低,但甜味氨基酸含量所占比例最高,为63.10%,并且呈味核苷酸含量最高,肌苷酸和腺苷酸的滋味强度值大于1。蟹的性腺部分,呈味核苷酸含量与味精当量值是3个可食部位中最高的,其中南海性腺的味精当量值为36.46 g MSG/100 g,是4个海域中最高。蟹的体肉部分中肌苷酸含量较高,黄海体肉肌苷酸组中含量较低,其滋味强度值小于1,对体肉的滋味无直接贡献,但黄海体肉组游离氨基酸总量最高,为2 564.44 mg/100 g;东海体肉组的味精当量值最高,为7.19 g MSG/100 g。     

Nutrient composition of green crab (Carcinus maenus) leg meat and claw meat

Research is underway in New England to examine the potential for initiating a commercial fishery for the invasive European green crab (Carcinus maenus). Information on the nutrient composition is needed to facilitate the processing, utilization, and marketing of value-added green crab products. Green crabs were harvested and individually weighed and measured for carapace width. Claw meat and leg meat samples were picked from steamed crabs, and raw crabs were sampled for claw meat only. Samples were subjected to proximate, mineral (calcium, phosphorus, magnesium, sodium, potassium, aluminium, iron, zinc, copper), cholesterol, eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) analyses. Moisture, protein, and total mineral contents of the crab meat averaged 78.7, 17.1, and 2.2 g/100 g, respectively. Leg meat had higher lipid concentrations (1.16 g/100 g) than either steamed (0.62 g/100 g) or raw (0.54 g/100 g) claw meat. Average n-3 fatty acid concentrations ranged from 115 to 336 mg/100 g and 154 to 344 mg/100 g for DHA and EPA, respectively, and were significantly higher in leg meat than in claw meat.