DTPA合成方法的研究

以氰化钠、甲醛及二乙烯三胺为原料在不同条件下合成DTPA，得到最佳反应条件。     

X-射线荧光光谱法快速测定粮食中镉含量

探讨了X-射线荧光光谱法快速测定粮食中镉含量的效果,并将这种方法与石墨炉原子吸收光谱法进行比较。结果表明,X-射线荧光光谱法镉检出限为0.026 mg/kg;定量限为0.061 mg/kg;仪器准确性、重复性以及稳定性均符合要求;台间差无显著性差异。X-射线荧光光谱法简单、操作方便、灵敏度高、无环境污染。可应用于现场收购,及时将镉超标粮食与非超标粮食分类存放,防止二次污染,对确保粮食质量安全具有重要意义。     

厨房措施对香菇中镉离子的浓度和生物可给性 及生物活性的影响

目的 探讨家庭厨房普通的处理方式对香菇中的镉(Cd)含量、镉的生物可给性以及其生物活性的影响。方法 用原子吸收检测家用酸、碱浸煮香菇不同部分的重金属含量变化, 对严重超标的Cd的生物可给性进行研究, 并采用电子自旋共振仪(ESR)对不同处理方式导致的生物活性变化进行检测。结果 香菇菇伞中的Cd含量高于菇梗中的Cd含量, 且都高于国家规定的最高允许值。家庭弱酸浸煮可以显著降低菇伞和菇梗中的Cd含量。用UBM法对体外模拟人体胃肠消化过程中Cd在胃和小肠的生物可给性研究表明, 胃液中的生物可给性显著比小肠阶段高, 并由此计算出人体健康风险因子, 其呈现出成人和儿童的每日摄入量均超过可耐受的每日摄入量。处理过的菇伞和菇梗的自由基清除能力都较未处理样品有显著降低。在相同浓度时(5 mg/mL), 1% NaHCO3和1% CH3COOH处理的菇伞对超氧阴离子自由基的清除能力均有显著增强, 但只有1% CH3COOH处理的菇伞对羟基自由基的清除能力有显著增强。结论 家庭弱酸浸煮可以显著降低香菇中的Cd含量; Cd在胃液中的生物可给性显著比小肠阶段高, 由此得出成人和儿童的每日摄入量均超过可耐受的每日摄入量各为4~5倍。酸、碱浸煮处理过的菇伞和菇梗的自由基清除能力都显著降低。     

Cooking rice in excess water reduces both arsenic and enriched vitamins in the cooked grain

This paper reports the effects of rinsing rice and cooking it in variable amounts of water on total arsenic, inorganic arsenic, iron, cadmium, manganese, folate, thiamin and niacin in the cooked grain. We prepared multiple rice varietals both rinsed and unrinsed and with varying amounts of cooking water. Rinsing rice before cooking has a minimal effect on the arsenic (As) content of the cooked grain, but washes enriched iron, folate, thiamin and niacin from polished and parboiled rice. Cooking rice in excess water efficiently reduces the amount of As in the cooked grain. Excess water cooking reduces average inorganic As by 40% from long grain polished, 60% from parboiled and 50% from brown rice. Iron, folate, niacin and thiamin are reduced by 50–70% for enriched polished and parboiled rice, but significantly less so for brown rice, which is not enriched.     

固体悬浮液进样石墨炉原子吸收法测定茶叶中的微量镉

探讨了固体悬浮液进样石墨炉原子吸收光谱法测定镉时的最佳分析条件,建立了茶叶中微量镉的石墨炉原子吸收光谱直接测定方法。采用琼脂溶液与悬浮剂将茶叶样品均匀、稳定地悬浮于琼脂溶胶中,由自动进样器直接将茶叶悬浮液注入石墨炉中,使用基体改进技术,石墨炉原子吸收法测定茶叶中的镉,省去了以往冗长、繁琐的样品化学前处理过程。在优化的条件下,本法测定镉的检出限为0.065μg/L,相对标准偏差小于5%,线性范围为0～10μg/L,标准样品测试回收率为94%～106%,方法简便、快速、准确,用本法测定茶叶(85601)标准样品,测定结果与标准标准值一致。     

微波消解-原子荧光光谱法测定饮料中镉

目的：建立原子荧光光谱法测定果汁饮料中镉的检测方法。方法：采用微波消解法消解果汁饮料样品后，用原子荧光光谱法测定其中的痕量镉的含量，对测定条件进行了优化，并对测定方法进行了方法学考察。结果：镉的校准曲线的相关系数r=0．9995，线形范围为0-60．0μg／L，检出线为0．0472μg／L，回收率为94．9％-100．5％，RSD为5％。结论：该方法快速、简便、准确且灵敏度高，为果汁饮料中镉含量的测定提供了较好的方法，用本方法测定标准样品达到满意效果。     

Mycorrhizal colonization and grain Cd concentration of field‐grown durum wheat in response to tillage,preceding crop and phosphorus fertilization

BACKGROUND: A 3‐year field trial was conducted to investigate the effect of agricultural management practices including tillage, preceding crop and phosphate fertilization on root colonization by arbuscular mycorrhizal (AM) fungi and grain cadmium (Cd) concentration of durum wheat (Triticum turgidum L.). The relationship between grain Cd and soil and plant variables was explored to determine the primary factors affecting grain Cd concentration. RESULTS: Mycorrhizal colonization of the roots was reduced by conventional tillage or when the preceding crop was canola (Brassica napus L.), compared to minimum tillage or when the preceding crop was flax (Linum usitatissimum L.). In contrast, grain Cd was not consistently affected by any treatment. Grain Cd was generally below the maximum permissible concentration (MPC) of 100 µg Cd kg^?1 proposed by WHO. Grain Cd varied substantially from year to year, and could be predicted with 70% of variance accounted for by using the model: grain Cd concentration = ? 321.9 + 44.5× ln(grain yield) + 0.26× soil DTPA‐Cd + 182.5× soil electrical conductivity (EC)? 0.98× grain Zn concentration. CONCLUSIONS: These common agricultural management practices had no effect on grain Cd concentration in durum wheat though they impacted mycorrhizal colonization of roots. Grain yield and to a lesser extent soil conditions of EC and DTPA‐Cd and grain Zn influenced grain Cd, whereas mycorrhizal colonization levels did not. Copyright © 2010 Crown in the right of Canada. Published by John Wiley & Sons, Ltd     

破乳诱导萃取-ICP-MS法测定食用油中镉的含量

建立破乳诱导萃取结合电感耦合等离子体质谱（inductively coupled plasma mass spectrometry,ICP-MS）法测定食用油中重金属镉含量的方法。优化关键实验参数（表面活性剂种类、表面活性剂质量浓度、硝酸体积分数以及食用油取样量）,应用优化的实验条件检测实际食用油样品。优化的实验条件为Triton?X-114作表面活性剂质量浓度0.09?g/mL、硝酸体积分数5%、食用油取样量2.0?g。该方法食用油中镉的检出限为0.031?ng/g,标准曲线的相关系数大于0.999?9,回收率在90.3%～105.0%之间。与传统的微波消解法对比,2?种方法得到的结果无显著性差异。此破乳诱导萃取法是一种简单、快速、绿色的样品前处理方法,结合ICP-MS可以实现食用油中镉的灵敏、准确检测。     

楠竹笋对土壤中铅和镉的吸收特征分析

为了研究楠竹笋生长时期对土壤中铅(Pb)和镉(Cd)的累积效应及在各器官中的分配特征,在竹笋生长期的楠竹林里,施加外源硝酸铅(Pb(NO₃)₂)和硝酸镉(Cd(NO₃)₂)模拟土壤不同污染程度:5 mg·m^-2轻度污染、50 mg·m^-2中度污染、500 mg·m^-2重度污染以及0 mg·m^-2(对照)4个浓度梯度的Pb、Cd,分析Pb和Cd在楠竹笋不同生长期及各器官中的富集、累积和分配特征。结果表明:笋中各部位Pb、Cd的富集与外施Pb、Cd浓度和时间呈正相关,竹笋体内Pb和Cd的累积量随时间推移、污染程度增强而明显增加。三种污染程度中,除重度污染笋底在第21 d Pb含量超标,楠竹笋可食部分Pb含量均低于国家食品卫生标准(1.0 mg·kg^-1);轻度、中度污染的竹笋可食部分Cd含量在0.02~0.14 mg·kg^-1,低于国家食品卫生标准(0.2 mg·kg^-1),然而重度镉污染使可食部分竹笋在第14 d以后含量超过国家食品卫生标准。重度污染时,施药第21 d后Pb、Cd在竹笋各器官中的累积百分比分别表现为笋根(73.84%、72.79%),笋底(6.33%、6.97%),笋中(2.52%、1.95%),笋尖(2.68%、0.52%),笋皮(14.63%、17.77%)。生物富集系数(BCF)和转移系数(TF)呈\     

电感耦合等离子体质谱法测定大米中总砷、镉和铅含量的不确定度评估

目的 评估电感耦合等离子体质谱法(inductively coupled plasma mass spectrometry,ICP-MS)测定大米中总砷、镉和铅含量的不确定度.方法 依据GB 5009.268—2016,利用电感耦合等离子体质谱法测定大米中总砷、镉和铅含量,按照CANS-GL 006:2018的评估方法...