KI-MIBK萃取法测定地表水中铜、镉、铅的改进

对KI-MIBK萃取火焰原子吸收法测定地表水中铜、镉、铅进行了改进。用100ml容量瓶代替分液漏斗取样、萃取和火焰原子吸收测定。改进法校准曲线的灵敏度和相关系数、精密度和准确度均优于标准法。

示波极谱法连续测定太湖流域大米中锌、铁、锰、铜、铅、镉含量

研究了示波极谱法在三乙醇胺-乙二胺-硫氰酸钾-乙酸-盐酸-碘化钾-十二烷基硫酸钠体系中连续测定太湖流域大米试样中锌、铁、锰、铜、铅、镉六种微量元素．在该体系中，六种微量元素分别在-1425mV、-1638mV、-1717mV、-508mV、-533mV、-668mV产生稳定的二阶导数极谱波．锌、铁、锰、铜和铅最低检出限为0．01μg·mL^-1，镉最低检出限为0．005μg·mL^-1，锌、铁、铜、铅的浓度在0．01～0．801μg·mL^-1，镉在0．005～0．80μg·mL^-1，锰在0．01～0．50μg·mL^-1范围内与极谱波峰高成正比．六种微量元素回收率范围：94．4％～103．5％，RSD：0．14％～8．72％．该方法操作简便，灵敏度和精确度高．该方法应用于太湖流域18种大米中六种微量元素的测定，与原子吸收分光光度法测得的结果基本一致．

ICP-MS测定婴幼儿奶粉中的铬、铜、硒、镉、汞、铅含量的方法学比较研究

采用微波消解体系和四种定量模式(标准曲线法、标准加入法(消解前加标和消解后加标)、同位素稀释质谱法)对婴幼儿奶粉中的铬、铜、硒、镉、汞、铅含量进行测定。结果表明用同位素稀释质谱法的测得值与理论值的最大相对误差为-10.7%、最大相对标准偏差为1.0%,优于其它三种定量模式,标准加入法次之,其中在消解步骤前加标可以减小易挥发成分在前处理过程中损失所带来的误差,标准曲线法所得数据的最大相对误差为-26.2%、最大相对标准偏差为3.4%,不适于复杂基体的定量分析。

石墨炉原子吸收法测定海水中痕量铜铅镉镍

石墨炉原子吸收法测定海水中痕量铜、铅、镉、镍,方法的特征浓度(1%吸收)分别为铜:0.808μg/L、铅:1.20μg/L、镉:0.063 7μg/L、镍:1.12μg/L,最低检出限分别为铜:0.24μg/L、铅:0.36μg/L、镉:0.019μg/L、镍:0.34μg/L。室内控样测试结果的相对误差分别为铜:3.5%、铅:0.8%、镉:4.2%、镍:4.9%,相对标准偏差分别为铜:5.6%、铅:3.6%、镉:5.3%、镍:5.8%。

水中铜、锌、铅、镉检测方法的研究进展

铜、锌、铅、镉污染日益成为水环境污染中的重点,因此,重金属污染防治任重道远,而检测手段的应用就非常重要。本文介绍了常见的检测水中铜、锌、铅、镉技术,包括分光光度法、电化学分析法、原子吸收分光光度法、电感耦合等离子体发射光谱法、电感耦合等离子体质谱法。分析了各种检测方法的优缺点,并展望了未来重金属检测的发展方向。

微波消解-原子吸收分光光度法测定海洋沉积物中的铜、锌、铅、镉、铬

采用微波消解-原子吸收分光光度法快速有效地测定了海洋沉积物中的铜、锌、铅、镉、铬。使用硝酸作为消解酸,利用微波消解样品,然后调节消解液的酸度,最后采用原子吸收分光光度法进行定性定量分析。对样品的消解方法、消解酸体系和基体改进剂进行了优化,并优化了仪器条件,最后进行了线性关系、回收率、精密度和检测限的考察.结果表明,海洋沉积物中的铜、锌、铅、镉、铬方法的线性范围内线性相关系数(R)均能达到0.999~0.999 7。5种元素的回收率为96.8%~103.3%,相对标准偏差(n=5)均小于10%,方法具有较好的准确性和精密度。

氯化钠在石墨炉原子吸收法测定铜、铅、镉时的干扰分析

在石墨炉原子吸收法测定铜、铅、镉时,样品中的氯化物因光散射给测定信号迭加上一个"假吸收",碱金属盐类因宽带分子吸收给测定信号迭加上一个"假吸收",该两项"假吸收"使测定结果偏高,产生正干扰;分析元素的波长越短,其干扰越严重;且随着氯化物和碱金属盐类含量的增大,干扰信号呈正比递增趋势。本实验用氯化钠作干扰物发现:氯化钠含量在20mg/L以上时即对镉的测定产生明显干扰;当氯化钠含量达到200mg/L时可对铅的测定产生明显干扰;而800mg/L以上的氯化钠溶液才对铜的测定产生明显干扰。

797 VA伏安极谱仪测定地表水中锌镉铅铜含量

本文建立了797VA阳极溶出伏安极谱仪测定地表水中锌镉铅铜含量的检测方法。在乙酸缓冲液pH=4.6中加入样品溶液,富集时间为60s,氮气脱氧时间为300s,相对标准偏差(n=6)为2.5%~5.5%,加标回收率为94.0%~109%。整个实验表明,797VA伏安极谱测定地表水中锌镉铅铜含量,满足环境水质监测的地表水锌镉铅铜的分析要求,简便可行。

原子吸收及原子荧光法测定太子参中铁、铅、砷、汞、铜、镉、锰

目的 建立石墨炉原子吸收光谱法及原子荧光法测定太子参中铁、铅、砷、汞、铜、镉、锰的含量.方法 通过优化微波消解条件,采用氘灯背景校正,在同一体系中连续测定不同元素.结果 在选定条件下,太子参中铁、铅、砷、汞、铜、镉、锰检出限分别为0.0042μg·mL-1、0.0052μg·mL-1、0.0062μg·mL-1、0.0085μg·mL-1、0.0039μg·mL-1、0.0064μg·mL-1、0.0047μg·mL-1.方法 加样回收率为89.5%～106.4%,RSD为1.81%～4.92%.结论 本方法准确、迅速、简便.

等离子发射光谱法同时测定西红柿叶标样(ESP-1)中铜、锌等含量

采用微波消解技术对西红柿叶标准样品(ESP-1)进行前处理,用等离子发射光谱法同时测定西红柿叶标准样品(ESP-1)中铜、锌、铁、锰、铅、镉的含量,结果表明:该方法快速准确,对同时测定植物样品以及其它固体样品中多种金属元素的含量具有很好的参考价值.

采集的生物膜中痕量重金属的形态分布特征

采用改进的Tessier连续萃取方法对从松花江中采集的生物膜中锰、铁、铜、铅、锌及镉的化学形态进行分析,考察了生物膜上铁、锰氧化物和有机质吸附重金属的相对作用,同时讨论了在研究培养的生物膜吸附痕量重金属时所建立的选择性萃取方法对于采集的生物膜组分分离的适用性.研究结果表明,在采集的生物膜上痕量重金属以铁、锰的氧化物为主要结合形态存在,以此种形态存在的铜、锌、铅和镉分别占其总含量的62.9%,58.3%,53.8%和32.6%,而以有机结合态存在的铜、锌、铅和镉,分别占其总含量的1.1%,0.6%,9.9%和1.8%,表明采集的生物膜上铁、锰氧化物在吸附重金属的过程中起主要的控制作用,而有机质的作用相对较小,与以往利用选择性萃取技术研究培养的生物膜吸附重金属的规律一致.进一步分析表明,如扣除生物膜上铁的残渣态部分,则选择性萃取分离技术可以有效地将采集的生物膜上的铁、锰氧化物及有机质分离开.

Reduction of Cd, Cu, Ni and Pb Mobility by Active Si

A series of column experiments were performed to investigate the mechanisms of silicon （Si） and heavy metals （HM） interaction in the soil. The column experiments were conducted with Gray Forest Soil treated by various forms of active Si （diatomaceous earth, zeolite, amorphous silicon dioxide and concentrated monosilicic acid） in environment polluted conditions with soluble salts of Cd, Cu, Ni and Pb. All Si-rich substances used in the test were analyzed with electron scan microscope. The results of HM immobilization in soil by Si-rich materials showed that diatomaceous earth and concentrated monosilicic acid immobilized HM better than zeolite and amorphous silicon dioxide. The reductions in HM mobility were re- alized by the reaction between monosilicic acid and HM in soil solution and by adsorption of HM on Si-rich surface. The intensity of HM movement through soil depended on the type of HM. The maximum reduction of HM mobility with application of Si-rich substances was obtained for Cd and Ni and less effect was observed for Cu and Pb.

蔬菜中重金属污染的主要因素及其监测技术的探讨

蔬菜中重金属(铜、锌、铅、镉、铬等)有毒物质的存在,主要来源于土壤污染,污水灌溉,废气流动。作者根据农业环境污染因素。对本市八种蔬菜、五种类型水,共计五十六个样品进行了监测,并利用火焰原子吸收法和无火焰原子吸收法分别试验、对比验证的方式,摸索出了一套火焰原子吸收光谱法测定蔬菜中铅、镉的监测技术。本法准确、稳定,回收率在90％以上,变异系数为10％左右,充分满足了分析方法的要求。这样一来,解决了不具备无火焰设备,也能监测含量较低的铅、镉有毒元素问题。通过化验得知:市郊区蔬菜中重金属成份的含量大于县城郊蔬菜中重金属成份的含量。

同一固废全消解液中Cu、Pb、Zn、Cd、Mn的原子吸收光谱测定方法研究

建立了固废中包括Cu、Pb、Zn、Cd和Mn等5种微量、痕量有害金属元素的原子吸收光谱测定方法。试验对微波消解条件、称样量、测定介质与仪器条件等进行了研究,试样经HNO3-HF微波消解,HClO4破坏有机质,在选定的试验条件下,使用原子吸收光谱仪对同一份样品中的痕量元素Cu、Pb、Zn、Cd和Mn进行连续测定。在仪器最佳工作条件下,方法检出限为:Cu0.037mg/L,Pb0.294mg/L,Zn0.030mg/L,Cd0.015mg/L,Mn0.022mg/L。相对标准偏差(RSD):Cu为3.1%,Pb为2.5%,Zn为4.0%,Cd为6.6%,Mn为4.2%。经过国家一级标准物质的分析验证,结果与标准值吻合较好。方法操作简单、可靠,可用于批量样品分析。

Effect of Heavy Metal Pollution on Potassium Behavior in Typic Udic Ferrisol

The indirect influence of heavy metal contamination of soil on nutrient availability, an important aspect of soil quality, may need to be taken into consideration when determining overall effects of heavy metals. A laboratory experiment was performed to study the effects of combined pollution of Cu, Ph, Zn and Cd on soil K status as indicated by chemical fractions, adsorption-desorption and quantity/intensity (Q/I) relationship of K in a Typic Udic Ferrisol (generally called red soil), by employing uniform design and single factor design. Compared to the control, content of exchangeable K was decreased, but that of soluble K increased in the samples contaminated with heavy metals. Due to heavy metal pollution, potassium adsorption was reduced by 5% to 22%, whereas the desorption percentage of adsorbed K increased by 2% to 32%. The Q/I curves shifted downward, potassium buffering capacity (PBCK) decreased, and equilibrium activity ratio values (ARoK) increased with increasing heavy metal pollution. These influences followed the sequences of Ph>Cu>Zn and combined pollution>single one. Displacement of K from canon exchange sites and decrease in soil CEC due to heavy metals should be responsible for the changes of soil K behaviours. The findings suggest that heavy metal pollution of soil might aggravate the degradation of soil K fertility by decreasing K adsorption and buffering capacity and increasing desorption.

Application of polymeric aluminum salts in remediation of soil contaminated by Pb,Cd,Cu,and Zn

Soil contaminated with typical heavy metals (Pb,Cd,Cu,and Zn) was remedied by using the polymeric aluminum salt coagulants including polyaluminum chloride (PAC) and polyaluminum sulfate (PAS).The remediation efficiencies are influenced by reaction time,water amount,and dosage of remediation agent.The optimal remediation conditions are as follows:6 h of reaction time,1 kg/kg of water addition amount,and 0.25 kg/kg of remediation agent dosage.After PAC addition,the remediation efficiencies of diethylenetriamine-pentaacetic acid (DTPA)-extractable Pb,Cd,Cu,and Zn reach 88.3%,85.1%,85.4%,and 73.7%,respectively;and those for PAS are 89.7%,88.7%,83.5%,and 72.6%,respectively.The main remediation mechanism of the polymeric aluminum salt may contribute to the ionization and hydrolysis of PAC and PAS.H + released from ionization of polymeric aluminum salt can cause the leaching of heavy metals,while the multinuclear complex produced from hydrolysis may result in the immobilization of heavy metals.For PAC,the immobilization of heavy metals is the main remediation process.For PAS,both leaching and immobilization are involved in the remediation process of heavy metals.

Effect of Heavy Metals on Phosphorus Retention by Typic Udic Ferrisols: Equilibrium and Kinetics

A study was conducted to examine the effect of heavy metals (Cu,Pb, Zn and Cd in combination or alone) on the equilibrium andkinetics of phosphorus (P) retention in typic udic ferrisols by usingboth equilibrium and flow techniques. Fourteen soil samples withvarying artificial contamination of Cu, Pb, Zn and Cd were prepared.Heavy metal pollution led to increases in retention capacity andmaximum buffering capacity (MBC) of soil P. The rate of P retentionwas also increased and the time to reach equilibrium was advanced byheavy metals addition.

Accumulation and Cycle of Heavy Metals in Sonneratia apetala and S. caseolaris Mangrove Community at Futian of Shenzhen, China

This paper reports the absorption, accumulation, distribution and cycle of Cu, Pb, Zn, Cr and Ni in S. apetala + S. caseolaris, mangrove community at Futian Mangrove Nature Reserve of Shenzhen. The Cu, Pb, Zn, Cr and Ni contents in forest soil increase from bottom to surface layers, and the storage of the five heavy metals in the surface layer (depth 0 ~ 30 cm) is Zn > Pb > Ni > Cr > Cu. The concentration ability is S. caseolaris > S. apetala > K. candel. The existing accumulation of Cu, Pb, Zn, Cr and Ni in the community μis 23 019.63g/m2μ, 23 429.66g/m2μ, 117 870.42g/m2μ, 6 835.80g/m2μ, and 12 995.22g/m2μ, respectively. The annual absorption is 6 592.57g/m2μ, 2 664.80g/m2μ, 23 123.56g/m2μ, 853.24g/m2μ, and 1 990.95g/m2, respectively. The annual return is μ3 179.50g/m2μ, 1 300.65g/m2μ, 7 401.31g/m2μ, 398.99g/m2μ, and 646.20g/m2, respectively. The annual net retention accumulation of Cu, Pb, Zn, Cr and Ni in the community is 3 413.07μg/m2, 1 364.15μ g/m2, 15 722.25μg/m2, 454.25μg/m2, and μ1 344.75g/m2, respectively. The turn over periods of Cu, Pb, Zn, Cr and Ni are 8,19,15,18 and 21 years, respectively.

石墨消解法—ICP-MS同时测定土壤中的六种元素

建立了石墨消解法进行土壤前处理,用电感耦合等离子-质谱法(ICP-MS)同时测定土壤标准物质中铅、镉、铬、铜、锌、锰六种元素的含量。该前处理方法减少了消化过程中元素的损失,研究了六种元素的校准曲线、检出限、精密度和准确度,测定值均在土壤标准物质的标准值允许误差范围之内,精密度都在10%以下。具有简便、快速、灵敏、稳定、准确等优点,适用于大批量土壤样品中多种元素的同时测定。

Chemical Associations of Heavy Metals in the Sediments near Bailonggang Sewage Discharge Outlet of Shanghai

The five chemical associations of heavy metals have been extracted continuously using the Tessier extracting method. Results show that Cu, Pb, Fe, Zn and Cr in the sediments are mainly distributed in residual fraction, while the major chemical association of Mn is carbonates. Carbonate heavy metals are converted into Fe-Mn oxides in autumn. And in the low tidal flat, after carbonates have changed into ionic heavy metals, some of the elements are transported to the overlying water. Cu, Pb, Fe and Mn have good correlations with each other, and Zn, Cr also show their similarity of chemical behavior in the sediments.