方便面调味料中重金属元素铅、砷检测

通过对10个品牌的方便面调味料中重金属铅、砷的含量测定,探知了铅、砷两种重金属元素在方便面中的含量状况。方法:采用石墨炉原子吸收光谱法测定样品中的铅,多通道原子荧光光度法测定样品中的总砷。结果:铅的线性回归方程为y=0.003x+0.012,r=0.9980,回收率为98.25%;砷的线性回归方程为y=36.35x+0.002,r=0.9999,回收率为100.1%。结论:所有的72个样品方便面调味料中均未发现超标现象。不同品牌的方便面以及相同品牌不同种类的方便面调味料中的重金属铅、总砷含量各不相同。     

婴幼儿配方奶粉中反式脂肪酸含量测定

通过对呼和浩特华润万家超市中采购的7个婴幼儿配方奶粉品牌,62个样品中的反-9-十八碳一烯酸甲酯和反-9,12-十八碳二烯酸甲酯两种反式脂肪酸含量状况的测定,探明反式脂肪酸在婴幼儿配方奶粉中的含量状况。采用气相色谱石英毛细柱外标法测定7个品牌62个样品的婴幼儿配方奶粉中反式脂肪酸含量。本法简单、快速、灵敏,适用于婴幼儿配方奶粉中的反式脂肪酸含量分析。不同品牌的婴幼儿配方奶粉中反式脂肪酸的含量各不相同,同一品牌不同阶段的婴幼儿奶粉含量也不相同。     

干巴菌中部分重金属元素及无机砷、 甲基汞含量分析

目的检测干巴菌中5种重金属总砷、总汞、铅、镉、铬及无机砷和甲基汞的含量,探讨干巴菌对重金属的生物富集作用。方法采用电感耦合等离子体质谱法检测总砷、总汞、铅、镉含量,采用液相原子荧光光度计联用检测无机砷、甲基汞的含量。结果 31份干巴菌样品中总砷、总汞、铅、镉的检出率均为100%,无机砷的检出率为50%,甲基汞在全部样品中均未检出。昆明的干巴菌样品中砷含量较高,达0.46 mg/kg;曲靖的干巴菌中铅含量有0.9997 mg/kg;镉含量较高,为0.46 mg/kg。结论总体来看不同地区的干巴菌中总砷、总汞、镉、铬、无机砷和甲基汞的含量处于较低水平,但铅含量偏高。干巴菌对重金属没有特异性吸收富集能力。     

市售婴幼儿辅助食品中砷、汞污染情况的调查与分析

目的调查国内市售多个品牌的婴幼儿辅助食品中砷、汞的污染状况以及6种砷形态和2种汞形态含量,分析婴幼儿食用市售婴幼儿辅食时砷、汞污染暴露的风险。方法采集国内市场中39个品牌的138个婴幼儿辅助食品样品,总砷和总汞采用电感耦合等离子体质谱仪(inductivelycoupledplasmasourcemass spectrometer, ICP-MS)进行分析,采用Hamilton PRP-X100阴离子分析柱和Agilent Eclipse plus C_(18)色谱柱分别分离砷形态和汞形态,流动相分别为25 mmol/L磷酸二氢铵水溶液:乙醇=99:1(V:V)(pH=8.0,氨水调节)和0.1%L-半胱氨酸-10 mmol/L乙酸铵水溶液:甲醇=95:5(V:V),高效液相色谱串联电感耦合等离子体质谱仪分析。结果138个样品中的总砷和总汞最高浓度值分别高达4250.9和695.7μg/kg,其中12个样品中的总汞含量超标,不合格率达到8.7%;所有样品中的砷胆碱(arsenocholine, AsC)、一甲基砷(methyl arsenic, MMA)和乙基汞均低于检出限;砷甜菜碱(arsenic betaine, AsB)、三价砷、二甲基砷(dimethylarsine, DMA)、五价砷和甲基汞的检出样品个数分别为25、68、36、135和48个;所有样品的无机砷含量均未超标,最高值为174.9μg/kg。结论市售婴幼儿辅助食品中的砷、汞存在一定程度的污染,应引起相关部门的重视。     

杭州市富阳区本地产大米中重金属含量水平及其膳食暴露评估

目的 了解杭州市富阳区本地产大米中重金属铅、镉、总铬、总砷和无机砷的含量水平,评估消费本地产大米对健康的潜在风险,为富阳区的粮食安全提供决策依据。方法 2018—2020年,在富阳辖区8个乡镇街道内采集成熟期水稻450份,同时采集超市销售大米样品50份作对照样品。样品采用优化的微波消解条件消化后,根据国家标准对4种重金属元素含量进行检测,计算大米中重金属的暴露量,并采用安全限值（MOS）或暴露边界值（MOE）法进行风险评估。结果 富阳区本地产大米样品的铅、镉、总铬和总砷的平均值含量水平分别为38.0、180、83.8、77.2μg/kg。其中,本地产大米中铅、总铬和无机砷的合格率为100%,而镉的超标率为26%,对照组市售大米的合格率为100%。铅、镉、铬和砷4种重金属元素的暴露对居民健康风险均可接受,风险高低表现为Cd>Cr>Pb>As。结论 根据膳食风险评估结果显示,居民消费富阳区本地产大米暴露4种重金属而引起的健康风险较低。     

松江区消费环节大米重金属污染状况及安全评价

目的 了解松江区消费环节大米中铅、镉、无机砷和总汞等重金属污染状况及摄入风险, 掌握本地区大米质量安全情况。方法 采集松江区消费环节大米样品344个, 测定铅、镉、无机砷和总汞含量, 采用单因子污染指数和内梅罗综合污染指数对大米中重金属污染程度进行评价, 并用可耐受摄入量对膳食风险进行初步评估。结果 大米中无机砷、铅、镉、和总汞的含量均符合食品安全国家标准, 平均含量分别为0.054、0.032、0.018和0.0023 mg/kg; 在344件样品中, 97%以上的单因子污染指数小于0.6, 综合评价为安全、处于清洁水平的样品占99.4%, 没有轻度污染以上的样品存在; 通过大米摄入铅、镉、无机砷和总汞的量远远低于可耐受摄入量, 但无机砷、镉在高暴露点位的膳食风险贡献率大于10%。结论 松江区消费环节大米重金属的污染情况比较乐观, 对人体健康的风险处于较低水平, 重金属安全情况总体可控。     

电感耦合等离子体质谱法快速测定烟用接装纸中砷、铅、镉、铬、镍、汞的研究

建立了电感耦合等离子体质潜法测定烟用接装纸中砷、铅、镉、铬、镍、汞含量的方法,并采用该方法测定了25个接装纸样品中的砷、铅、镉、铬、镍、汞含量.结果表明:①砷、铅、镉、铬、镍、汞的平均回收率在97.9%～101.6%之间;日内重复性变异系数<2%,日间重复性变异系数<5%;检出限分别为0.001 mg/kg,0.002 mg/kg,0.008 mg/kg,0.004 mg/kg,0.007 mg/kg,0.016 mg/kg.②所测25个接装纸样品中,7个样品超过砷的限量标准1 mg/kg,2个样品超过铅的限量标准5 mg/kg,镉、铬、镍、汞的含量全部低于其限量标准.     

芦蒿中铅、铬、汞、砷的含量分析与安全评价

采集南京市17个农贸市场、6个超市的芦蒿样品共37个,用原子吸收光谱法和原子荧光光谱法测定芦蒿中铅(Pb)、铬(Cr)、汞(Hg)、砷(As)的含量。结果表明:芦蒿中铅含量为0.35±0.10mg/kg,铬含量为0.22±0.10mg/kg,汞含量为0.01mg/kg,砷含量未检出。对照国家食品卫生标准,97.3%的芦蒿样品中铅含量超出食品中铅限量卫生标准,芦蒿样品中铬、汞、砷含量在限量卫生标准以内,芦蒿中铅的来源可能是产地环境质量的原因。     

石家庄市售液态牛奶和奶粉中重金属含量的检测及分析

目的调查石家庄市售牛奶和奶粉中铅、镉、汞和砷等重金属的污染状况。方法采用电感耦合等离子体质谱法对市售不同品牌的牛奶和奶粉中的污染物进行检测,并依据GB2762—2017《食品安全国家标准食品中污染物限量》对牛奶中的铅、镉、汞和砷对公众健康危害风险度进行研究。结果本研究共监测61份样品,铅、镉、汞、砷总合格率为100%。部分食品检出重金属,铅、镉、汞、砷的检出率分别为31.1%、7.69%、0%和0%。结论目前石家庄市市售牛奶中重金属污染总体水平较低,但部分牛奶和奶制品中仍有重金属检出,应引起重视。应采取针对性措施,补充完善相关标准,加强监管力度,以确保牛奶和奶粉的质量安全。     

部分市售茶叶中铅、铬污染状况调查

目的了解市售茶叶中铅、铬两种重金属元素的污染状况,调查茶叶中铅、铬的本底值,为食品安全风险评估提供数据支持。方法从7个省、直辖市和自治区采集了420份茶叶样品,样品包含人们日常消费的主要茶叶品种,采用GB 5009-12-2010和GB 5009-123-2003中石墨炉原子吸收分光光度法对样品中的铅、铬两种元素的含量进行测定,依据GB 2762-2012茶叶中铅的限量和NY 659-2003中铬的限量对结果进行判定。结果茶叶中铅的检出率为90.7%,超标率为0.48%,铬的检出率为93.1%,超标率为0.71%,合格率略高或持平于2005~2009年监测结果。不同产地、不同品种、不同包装形式的茶叶之间铅铬含量存在差异。结论市售茶叶中铅、铬两种重金属元素的总体污染较低,但个别样品存在铅、铬含量超标现象,应引起适当的关注。     

Mineral contents of some southern Italian wines. II. Determination of Li, Na, Mg, K, Ca, Co, As, Rb, Sr, Ag, Sb, Ba

Following our study of the mineral contents of some Southern Italian wines, this work reports on the detection of 12 elemental components. The elements were determined using ICP-AES, flame atomic emission or absorption spectroscopy. The values determined for Li, Na, Mg, K, Ca, Rb, Sr and Ba were within the usual ranges for wines (average values for these elements were: 0.010, 26.2; 94.4; 888; 94.0; 3.30, 0.82 and 0.11 mg/l respectively). All the wines contained low levels of As, the concentrations of which were always under 0.20 mg/l, the maximum level permitted by E.E.C. standards. The measuring of Co, Ag, and Sb led us to ascertain, in all the wines, concentrations lower than 0.01 mg/l for Co and Ag and below the instrumental detection level for Sb (0.06 mg/l). In a previous study wines from D.O.C. areas of Southern Italy were analysed by the technique of inductively coupled plasma atomic emission spectroscopy (ICP-AES), for 14 minerals. This paper deals with further investigation of the mineral composition of the same wines for different metal constituents, analysed by ICP-AES, flame atomic emission, or atomic-absorption spectroscopy (two techniques). The first technique was applied to the detection of Co, As, Sr, Ag, Sb, and Ba. The alkaline metals Li, Na, K, and Rb were determined by flame atomic emission, a technique which possesses better detection limits for these elements. For Mg and Ca the atomic absorption methods were applied.     

Isolation,Composition, Structure,Properties, Modifications,and Uses of Yam Starch

Starch is the major carbohydrate in yam tubers and can amount up to 80% of the dry matter. The starch quality determines the quality of food and industrial products made from yam tubers. This review summarizes the present knowledge of the isolation, composition, structure, property, modifications, and uses of starches from diverse yam species. Compared with other tuber and root starches, there is a lack of systematic information on the yam starches. This hinders the further development of yams as sustainable crops as well as the value‐added processing of the starches. Therefore, suggestions on how to better understand and utilize these starches are provided.     

卷烟中锂、铬、镍、铜、砷、硒、钼、镉、铊和铅含量分析

采用微波消解-电感耦合等离子体质谱法测定了41个牌号烤烟型卷烟和雪茄烟样品烟丝中的锂、铬、镍、铜、砷、硒、钼、镉、铊和铅含量,并按照类型和价位对卷烟中这10种有害元素含量进行了统计分析。结果发现:①卷烟中锂和铜的含量较高,铊的含量很低,铬、镍、镉、铅、砷、硒和钼7种元素的平均含量为0.55～4.42μg/g;②雪茄烟中铬、镍、砷、钼、镉、铊和铅的含量一般高于烤烟型卷烟,而硒元素的含量则相反,但差别较小;烤烟型卷烟中锂和铜的含量与雪茄烟没有显著差异;③高档卷烟中的锂、镍、镉、铊和铬含量较低,而砷、铅的含量较高;不同价位卷烟的铜、硒和钼含量差异不显著。     

Survey of trace elements (Al,As, Cd,Cr, Co,Hg, Mn,Ni, Pb,Se, and Si) in retail samples of flavoured and bottled waters

Concentrations of eleven trace elements (Al, As, Cd, Cr, Co, Hg, Mn, Ni, Pb, Se, and Si) were measured in 39 (natural and flavoured) water samples. Determinations were performed using graphite furnace electrothermetry for almost all elements (Al, As, Cd, Cr, Co, Mn, Ni, Pb, and Si). For Se determination hydride generation was used, and cold vapour generation for Hg. These techniques were coupled to atomic absorption spectrophotometry. The trace element content of still or sparkling natural waters changed from brand to brand. Significant differences between natural still and natural sparkling waters (p < 0.001) were only apparent for Mn. The Mann–Whitney U-test was used to search for significant differences between flavoured and natural waters. The concentration of each element was compared with the presence of flavours, preservatives, acidifying agents, fruit juice and/or sweeteners, according to the labelled composition. It was shown that flavoured waters generally increase the trace element content. The addition of preservatives and acidifying regulators had a significant influence on Mn, Co, As and Si contents (p < 0.05). Fruit juice can also be correlated to the increase of Co and As. Sweeteners did not provide any significant difference in Mn, Co, Se and Si content.     

The effect of storage of canned juices on content of the metals Fe, Cu, Zn, Pb, Sn, Al, Cd, Sb and Ni

The increase in concentration of iron, copper, zinc, lead, antimony, aluminium, cadmium, tin and nickel over a 2 year's time of juices of peach (prunus persica), pear (pyrus communis), apricot (prunus vulgaris) and apple (malus pumila) was determined. The results show a considerable increase in Fe, Cu, Pb, Zn and Sn with time, while the change in Al, Cd, Ni and Sb is negligible.     

Analysis of cheese for histamine, tyramine, tryptamine, histidine, tyrosine, and tryptophane

A method is described for determining the content of selected biologically active amines (histamine, tyramine, tryptamine) and amino acids (histidine, tyrosine, tryptophane) in cheeses by high performance liquid chromatography. The amines and amino acids were quantified by employing a counter ion-containing mobile phase and by comparing peak areas of high performance liquid chromatography charts for sample cheeses versus standard cheeses containing known amounts of added amines based on dual injections of samples and standards. Recovery of amines and amino acids varied from 87.5 to 111%. Histamine, which has been associated with food poisoning in concentrations of 185 mg/100 g in Swiss cheese and 180 to 500 mg/100 g in fish, was found in concentrations above 500 mg/100 g in Swiss cheese. The high performance liquid chromatography analytical method should be useful for screening to detect cheese samples containing toxic amounts of histamine and for research studies designed to determine the cause and effect relationships for histamine production in cheese.     

In Vitro Digestion of Raw,Roasted, and Pressure-Flaked Corn, ,

We compared raw, roasted, and pressure-flaked com in dry matter and starch digestion studies in vitro. For dry matter digestion, incubations were 1, 4, 8, 16, 24 and 48 h. Dry matter digestion was increased in hours 1 through 24 by processing. Digestion in the 48-h period was decreased by processing which suggests that processing may increase the ease of utilization but not total utilization. Roasting decreased 48-h dry matter digestion more than pressure flaking. Starch digestion with incubations 1, 4, 24, and 48 h favored processed corn at all hours except 4. The 48-h observations from both studies indicate that while processing enhances starch utilization, it impairs utilization of other components in the grain. Prediction equations for dry matter and starch digestion for each corn treatment from length of incubation period and squared length of incubation period had multiple correlations of .96 or greater.     

Varied Composition of Tocochromanols in Different Types of Bran: Rye,Wheat, Oat,Spelt, Buckwheat,Corn, and Rice

The profiles of tocopherol (T) and tocotrienol (T3) homologues in 37 samples of seven different types of bran (rye, wheat, oat, spelt, buckwheat, rice, and corn), available on the Polish market, were studied. Tocochromanols were identified and quantified by reverse phase-high-performance liquid chromatograph/fluorescence detector and reverse phase-ultra performance liquid chromatography-electrospray ionization/mass spectrometry. Only rice bran contained all eight tocochromanol types. Corn bran lacked β-T3; rye, wheat, oat, and spelt bran lacked γ-T3 and δ-T3; and buckwheat bran lacked β-T3, γ-T3, and δ-T3. In buckwheat and corn bran tocopherols predominated (98 and 78%, respectively); whereas rye, wheat, oat, spelt, and rice bran were rich in tocotrienols (78, 76, 66, 87, and 66%, respectively). The average total tocochromanol contents in the oat, corn, spelt, buckwheat, wheat, rye, and rice bran were 5.5, 16.2, 15.8, 14.7, 12.8, 10.7, and 9.1 mg/100 g of dry weight, respectively. Tocochromanol concentrations in samples of the same type bran from different sources varied considerably. Better labeling of bran products to reflect this variation would assist with control of vitamin E daily dietary requirements.