人群尿液中铬元素的电感耦合等离子体-质谱快速测定法

目的采用碰撞/反应池电感耦合等离子体-质谱(ICP-MS)技术,建立快速测定人群中尿铬元素的分析方法。方法尿样经体积分数为0.5%的硝酸溶液稀释10倍后,直接采用ICP-MS分析方法进行分析,以钇元素为内标,并采用碰撞/反应池技术消除质谱干扰。结果方法的测定范围为0.20~10.00μg/L,相关系数为0.999 9,检出限为0.10μg/L,定量下限为0.33μg/L。平均回收率在97.00%~102.25%之间,批内、批间精密度均5.00%,样品在-20℃冰箱中至少可保存14 d。结论该方法各项指标均满足GBZ/T 210.5-2008《职业卫生标准制定指南第5部分:生物材料中化学物质的测定方法》的要求,适用于人群中尿铬元素的快速检测。     

碰撞/反应池-电感耦合等离子体质谱法同时测定肉类食品中的5种有害元素

目的建立碰撞/反应池-电感耦合等离子体质谱法(KED/DRC-ICP-MS)同时测定肉类食品中5种有害元素(铅、镉、铬、镍、砷)的分析方法。方法采用压力罐密闭消解方式进行样品前处理,同时使用动能歧视技术,He作为反应气体;动态反应池技术,NH_3作为反应气体,消除质谱测定中的多原子离子光谱干扰。结果实验表明,该方法中采用动能歧视技术、动态反应池模式测定时,灵敏度和精密度不会降低,与标准模式相比更加稳定,准确度更好。各元素线性关系良好(r0.999 0),方法的检出限为0.023 7μg/L~0.079 5μg/L,回收率为95.1%~103.8%,相对标准偏差(RSD)4.32%。结论该方法准确、简便、快速、灵敏,可为肉类食品中重金属元素的检测与控制提供方法参考。     

碰撞池ICP-MS法测定全血中铬元素

目的:建立全血样品中铬元素的电感耦合等离子体质谱(ICP-MS)检测方法。方法:采用0.5%HNO3-0.01%曲拉通X-100体系对全血进行稀释10倍后,直接进行ICP-MS分析,选取Sc作为在线内标,并采用碰撞反应池(CCT)技术来消除铬元素的质谱干扰。结果:方法线性相关系数0.999,方法检出限为0.07μg/L,平均加标回收率在93.6%~96.8%,相对标准偏差小于3.44%。结论:ICP-MS法简便、快速、准确,适用于全血中铬元素的测定。     

催化光度法测定水中痕量铬

目的:建立一种简便、快速、灵敏、准确的痕量铬测定方法,检测水中痕量铬含量。方法:Cr6+对硫酸介质中过硫酸铵氧化邻甲氧基酚的反应具有明显的催化作用,对反应性能和条件进行研究,由此建立一种测定水中痕量Cr6+的新催化光度法。结果:实验测定Cr6+浓度在0.0006~0.06 mg/L范围内呈良好线性关系,方法检出限为5.42×10-10g/m l,应用于几种环境水样中Cr6+的含量测定,RSD小于3.27%,样品加标回收率为97.6%~101%。结论:该方法简便、快速、灵敏度高、选择性好,技术参数符合方法检测的要求。     

液相色谱-电感耦合等离子体质谱法测定水中铬形态

目的建立液相色谱-电感耦合等离子体质谱法测定水中铬(Ⅲ)与铬(Ⅵ)的方法。方法采用动态反应池(Dynamic Reaction Cell,DRC)消除水体样品中碳和氯对铬ICP-MS测定的干扰,~(52)Cr可作为铬形态分析的同位素。水样和铬形态标准溶液经复配络合剂络合,45℃放置10 min,采用DionexIonPac AS19(4 mm×250 mm)阴离子交换柱作为分析柱;以pH值=9.2 60 mmol/L硝酸铵溶液作为流动相,流速为1 ml/min。结果所建方法13 min内完成分析,铬(Ⅲ)与铬(Ⅵ)有很好的分离度,线性范围为1μg/L～50μg/L,线性相关系数r0.999 5,检出限分别为0.40μg/L和0.28μg/L;水中加标低、中、高3个浓度水平,加标回收率在90.8%～100.2%,相对标准偏差(RSD)分别为4.30%和2.38%。结论本方法灵敏度高、分析时间短、重现性及准确性好,适用于水体中铬形态的测定,为环境水体、饮用水及管材的安全监督检测提供切实可行的检测方法。     

全自动石墨消解-电感耦合等离子体质谱法快速测定唾液中16种元素

目的建立全自动石墨消解-电感耦合等离子体质谱快速测定唾液中16种元素的分析方法。方法采用全自动石墨消解对唾液样品进行前处理,消解完成后用1%硝酸定容,以103Rh、185Re作为内标消除非质谱干扰,碰撞反应池技术消除质谱干扰,采用电感耦合等离子体质谱快速测定唾液中16种元素。对测定的干扰及消除展开探讨并进行了系列可行性试验。结果本法在0. 5μg/L～100μg/L内线性良好(r≥0. 999),相对标准偏差为2. 56%～4. 89%,方法检出限为0. 006 0μg/L～0. 49μg/L,回收率为86. 2%～107. 2%。结论该方法简便快速、灵敏度高且重现性好,适用于唾液样中16种元素快速批量测定。     

水中砷和铁的反应池-电感耦合等离子体质谱测定法的改进

目的建立水中砷和铁反应池-电感耦合等离子体(ICP)-质谱(MS)直接测定法。方法样品直接进行ICP-MS引入分析,采用在线内标法及反应池技术校正干扰。结果该方法能有效消除质谱干扰及非质谱干扰。10μg/L时As背景等价浓度为0.041μg/L,Fe为1.893μg/L,RSD3.0%,As和Fe回收率分别为98.6%~103.0%、101.1%~104.5%。结论该方法简便、快速、准确,完全能够满足水中砷、铁的检测要求。     

生活饮用水中铁的电感耦合等离子体质谱测定法干扰因素的研究

目的研究电感耦合等离子体质谱(ICP-MS)法测定生活饮用水中铁的干扰因素,寻找去除干扰方法。方法以56Fe、57Fe作为定量同位素,配制含有不同干扰物质(10～300mg/L的SO42-和Cl-,0～100mg/L的Na+和Ca2+,0～50mg/L的K+和Mg2+)的水样,采用ICP-MS法进行共存离子干扰实验。在钙含量在1.2～100.6mg/L时,观察CeO+/Ce+、带碰撞-反应池、普通ICP-MS仪测定铁含量的差异,并与火焰原子吸收分光光度(AAS)法的测定结果进行比较。结果当Na+在100mg/L以下,K+、Mg2+在50mg/L以下,SO42-和Cl-在300mg/L以下时,对56Fe、57Fe测定均无干扰。当Ca2+浓度在10～100mg/L时,相对偏差为10.2%～76.5%。当CeO+/Ce+为0.98%时,对56Fe、57Fe测定均有干扰;当CeO+/Ce+为0.47%时,对57Fe测定有干扰。56Fe、57Fe均可作为碰撞-反应池-ICP-MS仪的定量同位素。57Fe不能作为普通型ICP-MS的定量同位素。结论生活饮用水基体中钙是普通型ICP-MS法测定铁的干扰因素。当有一定含量钙存在时,调低CeO+/Ce+、应用带碰撞-反应池的ICP-MS仪器可消除一定的干扰。     

微波消解-石墨炉原子吸收光谱法快速测定土壤中铬

目的探讨微波消解(MD),石墨炉-原子吸收光谱法(GF-AAS),快速检测土壤中铬的最佳方法。方法对土壤样品采用硝酸+盐酸+氢氟酸(3:1:1),微波消解,消解后用高温快速除酸,GF-AAS进行样品测定,计算定量。结果铬标准溶液吸光度在0.00μg~50.00μg/L浓度范围内,线性关系良好,该法检出限0.38μg/g,相关系数r=0.999 3,样品加标回收率88.2%~100.3%,RSD 4.0%。结论该法不仅快速而且简便,是一种准确和可靠的方法,非常适合测定土壤中的铬。     

标准加入-碰撞/反应池技术ICP-MS法测定酱油中As的应用

目的探索标准加入-碰撞/反应池的电感耦合等离子体质谱(ICP-MS)法测定酱油中的As的方法。方法样品经20倍稀释后直接引入ICP-MS进行分析,采用在线内标法及碰撞池/反应池技术校正干扰。结果该方法能有效消除谱线干扰、基体干扰和物理干扰。等价背景浓度为0.66μg/L(He)和,0.50μg/L(O2)时,精密度优于5.6%,用加标回收考察准确性,As回收率在85.6%~106.5%之间。结论该方法简便,快速,准确,完全能够满足酱油中As的检测要求。     

2020年陕西省主产农作物中总铬含量调查及评价

目的 了解陕西境内主产农作物的总铬含量并评价其相关健康风险。方法 根据2020年陕西省食品污染物和有害因素风险监测方案进行样品采集和检测，以食品安全国家标准 (GB 2762 - 2017)规定的限量为标准对谷物和新鲜蔬菜中的总铬含量进行评价，且评估居民经食用途径所致铬的暴露量，同时应用美国环保局推荐的健康风险评价模型对其引起的健康风险进行评估。结果 采集蔬菜、水果、谷物三类农产品, 共计840份样品，并对其总铬含量进行测定，其中谷物的检出率最高，为96.8%(242/250)，尤以101份小麦的含量最高，平均值为0.648 mg/kg，超标率为13.86%(14/101)；从行政区域方面看，渭南与西安地区所产农作物的总铬含量明显高于其他地区，导致两地居民的总铬暴露量明显偏高，高于容许摄入量Cr(Ⅵ)3 μg/kg bw/day；文中以总铬含量代替Cr(Ⅵ)进行健康风险评估，得到的风险值高于国际放射防护委员会(ICRP)推荐可接受风险值的5.0×10 - 5 a - 1，亦高于美国环保局(EPA)推荐的可接受终生癌症风险(lifetime cancer risk, LCR)值的1.0×10 - 4 a - 1。结论 本文以总铬含量代替Cr(Ⅵ)参与健康风险评估，所得的风险值属于高估。陕西境内主产农作物中小麦的总铬含量较高，存在超标情况，作为居民日常膳食的主要消费食品，有必要进一步对其铬形态展开调查。     

含铬工业废水对地下水及饮用水致突变性的影响

目的探讨安阳自行车厂排放的含铬工业废水对地下水及饮用水致突变性的影响。方法分别在自行车厂西南、厂门口、厂东60m处采集地下水样,并沿污水排放方向分别在卷烟厂、铁合金厂、火柴厂、化纤厂采集地下水样,并采集了自来水厂原水及管网水样,均测定水样六价铬(Cr6+)含量并利用蚕豆根尖细胞微核试验测定水样致突变性。结果水样Cr6+含量从自行车厂门口至化纤厂呈下降趋势(0.3585～0.0100mg/L),厂门口和厂东60m处地下水Cr6+含量分别超标6.17、2.08倍。水厂原水及管网水Cr6+含量分别为0.0123、0.0095mg/L。除化纤厂外,其余水样所致微核率比阴性对照均有不同程度升高。仅火柴厂地下水样的微核率显著高于阴性对照,差异有显著性(P<0.01)。结论安阳自行车厂附近的地下水不同程度地受到该厂排放的含铬工业废水的污染,但致突变性较弱。该市饮用水Cr6+含量符合卫生标准。     

Assessment of EDTA in Chromium (III–VI) Toxicity on Marine Intertidal Crab (Petrolisthes laevigatus)

Chromium poses a potential threat to coastal ecosystems. We used standard toxicity bioassays (semi-static, chronic) to evaluate EDTA as a chelating agent for reducing trivalent and hexavalent chromium toxicity on Petrolisthes laevigatus. Crab survival decreased linearly with increased chromium concentrations and dropped significantly beginning at 40 mg/L Cr (VI) and 80 mg/L Cr (III). No significant differences were observed with Cr (III) + EDTA as compared with untreated controls. Cr (VI) toxicity was greater than that of Cr (III), with low individual survival rates. The protective effect of EDTA in the medium increased crab survival by 41%-48%.     

Placental transport of chromium.

Since trivalent chromium (Cr+3) transport into certain tissues is rapid, the placental transport of injected high specific activity 51Cr+3 was studied in pregnant rats at days 17-20 of gestation. Three days after the intravenous injection of 51Cr+3, body retention of 51Cr was similar in pregnant and nonpregnant rats, but in the pregnant rats placentofetal uptake of 51Cr accounted for 25-30% of the 51Cr retention. The mean 51Cr content per placentofetal unit was 0.89 +/? 0.03% injected dose. Serum and tissue 51Cr contents per milliliter or gram in the pregnant rats were decreased by 50-80% except in uterus, which was unchanged. Tissue/serum 51Cr ratios were increased by 70-300% in the pregnant rats compared to the nonpregnant controls. These results indicate that the placentofetal unit is capable of extracting large amounts of Cr from the mother, and support the suggestion that maternal Cr is depleted during pregnancy. The data also suggest that body tissues may defend their Cr stores against Cr depletion by adaptive cellular Cr transport mechanisms.     

Placental transport of chromium

Since trivalent chromium (Cr+3) transport into certain tissues is rapid, the placental transport of injected high specific activity 51Cr+3 was studied in pregnant rats at days 17-20 of gestation. Three days after the intravenous injection of 51Cr+3, body retention of 51Cr was similar in pregnant and nonpregnant rats, but in the pregnant rats placentofetal uptake of 51Cr accounted for 25-30% of the 51Cr retention. The mean 51Cr content per placentofetal unit was 0.89 +/- 0.03% injected dose. Serum and tissue 51Cr contents per milliliter or gram in the pregnant rats were decreased by 50-80% except in uterus, which was unchanged. Tissue/serum 51Cr ratios were increased by 70-300% in the pregnant rats compared to the nonpregnant controls. These results indicate that the placentofetal unit is capable of extracting large amounts of Cr from the mother, and support the suggestion that maternal Cr is depleted during pregnancy. The data also suggest that body tissues may defend their Cr stores against Cr depletion by adaptive cellular Cr transport mechanisms.     

具六价铬高度耐受和祛除能力菌株的分离

目的从六价（Cr^6＋）铬污染环境中分离具有Cr^6＋高度耐受和祛除能力的菌株,以用于处理含高浓度Cr^6＋的废水。方法从Cr^6＋严重污染的河流中采集河底淤泥样品,采用选择性增菌培养筛选Cr^6＋耐受菌株,并从中进一步筛选Cr^6＋祛除的高效菌株。水中Cr^6＋的含量用二苯碳酰二肼分光光度法测定。结果从淤泥样品中分离出了20株能耐受300mg/LCr^6＋的菌株,其中Cr^6＋祛除能力最强的14号和18号菌株,分别能在144h内,使Cr^6＋浓度为200mg/L的LB培养液中Cr^6＋清除94.0%和100.0%。结论在铬（Ⅵ）污染的环境中分离出了高度耐受和祛除水中铬（Ⅵ）的菌株。     

微波消解-石墨炉原子吸收法测定蜂胶中重金属铬

目的用微波消解-石墨炉原子吸收法测定蜂胶胶囊壳中铬的含量。方法采用微波消解法对蜂胶胶囊壳进行消解,在波长357.9 nm下,通过石墨炉原子吸收进行测定。结果线性关系良好,相关系数r=0.999 5,检出限为0.08 mg/kg,5个批次的20份蜂胶胶囊中铬结果均不超标。结论该方法测定蜂胶胶囊中的铬简便、快速、准确。     

Light intensity influences chromium bioaccumulation and toxicity in Scenedesmus acutus (Chlorophyceae)

The influence of light intensity on chromium uptake was studied in two strains of the freshwater unicellular alga Scenedesmus acutus (Chlorophyceae) having different sensitivity to Cr poisoning and light intensity. The two strains were subjected to different Cr treatments at 3000 and 80 lux. Cr toxicity was assessed by algal growth rate, recovery test, methylene blue staining, and determination of photosynthetic activity. After 2 and 4 days of treatment, bioaccumulated chromium, cell dry mass, and protein and carbohydrate contents were also assessed. When the algae were treated at 3000 lux, different bioaccumulation patterns were obtained when Cr content was related to dry mass, cell number, or protein content. A direct relationship between Cr content and cell mortality was observed only when the amount of Cr was related to protein content. In both strains Cr uptake was slower in subdued light, suggesting that it is linked to energy-dependent processes. The difference between the strains in sensitivity to Cr poisoning was also evident in subdued light.     

Determination of chromium picolinate and trace hexavalent chromium in multivitamins and supplements by HPLC-ICP-QQQ-MS

Chromium picolinate (CrPic) and trace hexavalent chromium (Cr(VI)) content were characterized in VITA-1 and VITB-1, two new multivitamin and mineral supplement candidate reference materials from National Research Council Canada, by two methods of high performance liquid chromatography inductively-coupled plasma triple quadrupole mass spectrometry. The conditions for the separation of Cr(VI) from EDTA-complexed Cr(III) were optimized such that species interconversions were not observed during analysis. Following extraction with dilute NH₄OH in water at pH 10 (for Cr(VI)) or 3:2 acetonitrile:water (for CrPic) and quantification by standard addition, it was concluded that CrPic accounted for 95–96 % of the Cr in VITA-1 and VITB-1, while Cr(VI) was not present above the detection limit of 0.13 μg Cr g⁻¹. Using the two developed methodologies, commercially-available nutritional supplements, in the form of vitamin tablets and dried food supplements, were assessed, and it was determined that CrPic accounted for the majority (92 %–98 %) of the chromium present in the tablets, and that Cr(VI) concentrations were below the detection limit for all samples except for the powdered beets where it accounted for nearly half of the total Cr present.     

Accumulation and Distribution of Trivalent Chromium and Effects on Hybrid Willow (<Emphasis Type="Italic">Salix matsudana</Emphasis> Koidz × <Emphasis Type="Italic">alba</Emphasis> L.) Metabolism

The metabolic response of plants to exogenous supply and bioaccumulation of trivalent chromium (Cr³⁺ ) was investigated. Pre-rooted young hybrid willows (Salix matsudana Koidz × alba L.) were exposed to hydroponic solution spiked with CrCl₃ at 24.0°C ± 1°C for 192 hours. Various physiologic parameters of the plants were monitored to determine toxicity from Cr exposure. The transpiration rate of willows exposed to 2.5 mg Cr/L was 49% higher than that of the untreated control plants, but it was decreased by 17% when exposed to 30.0 mg Cr/L. Significant decrease (≥20%) of soluble protein in young leaves of willows was detected in the treatment group with ≥7.5 mg Cr/L. The measured chlorophyll contents in leaves of treated plants varied with the dose of Cr, but a linear correlation could not be established. The contents of chlorophyll in leaves of willows exposed to ≥7.5 mg Cr/L were higher than that of the untreated plants but lower at 30.0 mg Cr/L. Superoxide dismutase activity (SOD) in leaves between the treated and untreated willows did not show any significant difference, but activities of both catalase (CAT) and peroxidase (POD) in leaf cells of all treated plants were higher than those in the untreated willows. The correlation between the concentration of Cr and CAT activity in leaf cells was the highest of all toxicity assays (R ² = 0.9096), indicating that CAT activity was most sensitive to the change in Cr³⁺ doses compared with the other selected parameters. Results from the Cr uptake study showed that significant removal of Cr from hydroponic solution was observed in the presence of hybrid willows without showing detectable phytotoxicity, even at high does of Cr. More than 90% of the applied Cr³⁺ was removed from the aqueous solution by willows at concentrations up to 7.5 mg Cr/L. Approximately 70% of the initial Cr was recovered in the plant materials. At the low-Cr³⁺ treatment (2.5 mg Cr/L), Cr accumulation by willow materials was the greatest (92%) in roots and the lowest (0.2%) in leaves, whereas the greatest (66%) was in stems and the lowest (0.1%) in leaves of willows exposed to 30.0 mg Cr/L. The correlation between applied Cr³⁺ (mg Cr/L) and Cr (μg Cr/g fresh weight [fw]) accumulated in plant materials was significant. The bioaccumulation kinetics of Cr by hybrid willows can be described by a typical saturation curve. Results also indicated that translocation of Cr from roots to shoots was possible. It is to conclude that hybrid willows have great potential as bioremediation technology in the removal of chromium (Cr³⁺) from contaminated effluents and sediments.