原子荧光光谱法测定蔬菜样吕中铅

铅作为一种对人体有害元素，在蔬菜样品中必须被检测。应用原子荧光光度计检测铅中的含量，具有取样量少、灵敏度高、检出限低等优点，先例于环境样品的分析检测。     

广东省部分基地蔬菜重金属污染评价

通过对来源于广东省516个蔬菜种植基地18种蔬菜品种1 465个样品中铅、镉含量的检测分析,结果表明：蕹菜品种铅平均含量最高（0.11mg·kg^-1）,西洋菜镉平均含量最高（0.060mg·kg^-1）;总样品铅检测合格率97.0%,镉检测合格率98.9%;所检蔬菜品种的铅、镉平均污染指数均小于0.7。表明广东省各生产基地的蔬菜重金属安全状况总体较好,处于优良水平。     

成都地区蔬菜中重金属污染分析与评价

通过对成都地区的9种蔬菜152个样品的可食部分中重金属元素的分析研究，查明了蔬菜中重金属汞、砷、铅、锡的含量及分布特征。结果表明，锡和铅是成都地区蔬菜中的主要污染元素，在检测的蔬菜样品中，锡和铅的超标率分别为29．4％和22％，最高超标分别为5.60倍和2.86倍，汞和砷无超标现象。     

氢化物发生原子荧光法测定钻井废水中的铅

目前测定铅的分析方法主要有分光光度法、阳极溶出伏安法、示波极谱法、原子吸收法等。针对比色法灵敏度低,试剂不稳定;电化学法干扰严重;而原子吸收法,线性范围窄,样品用量大等问题,江苏油田采用氢化物发生原子荧光法测定钻井废水中的铅。样品经HNO3-HClO4消解,3％～4％KBH4还原,以0.8％～1.5％的HCl为介质,加入10％K3Fe(CN)6和2％H2C2O4基体改进剂,用原子荧光法连续测定钻井废水中的铅。铅的检测限为0.61ng/mL,回收率为87.4％～146％,变异系数＜4.2％。该方法操作简单,灵敏度高。     

水中铅的测定方法比较

由于水中铅的含量较低,常用的测定方法是石墨炉原子吸收法和氢化物发生-原子荧光法。通过对干扰的消除方法、检出限实验、加标回收实验以及检测消耗时间和涉及药品试剂等方面的比较,得出石墨炉原子吸收法和氢化物发生-原子荧光法检测水中铅的优劣:石墨炉原子吸收法前处理较为简单,所涉及药品较少,成本较低,适合大批量样品检测;氢化物发生-原子荧光法的精密度高于石墨炉原子吸收法,适合于科研型实验研究。     

电热板消解ICP-AES法测定农田土壤中的重金属

选用盐酸-硝酸-氢氟酸-高氯酸消解体系,用电热板对土壤样品进行消解处理,采用电感耦合等离子体发射光谱法(ICP-AES)对土壤样品中铜、铅、锌、铬、锰、镍进行定量分析。实验表明,样品中所测重金属含量均满足国家二级标准,结果准确可靠,重复性好。且该方法操作简单,进样量少,定量迅速,准确度高,可同时检测多种元素,能够满足环境样品的分析。     

氢化物发生原子荧光光谱法测定饮用水中的铅

通过改变仪器条件及试剂配比进行优选实验,利用原子荧光光谱法测定饮用水中的铅可知:铅的检出限是0.020μg/L,能够满足GB 5749-2006《生活饮用水卫生标准》的要求;同时原子荧光光谱仪分析样品灵敏度高、重现性好、干扰少、操作简便、分析快捷,测定样品的准确度和精密度均能达到质量控制要求。     

广东徐闻县绿色食品（菠萝）基地土壤重金属状况研究与评价

对广东省徐闻县5个乡镇土壤样品中重金属（镉、汞、砷、铅、铬和铜）含量进行了检测,采用单因子指数法对其结果进行评价。结果表明,徐闻县绿色食品原料（菠萝）基地土壤中6种重金属元素含量均在标准规定范围内,5个乡镇的土壤环境质量均为一级,达到安全清洁水平。     

不同粒径土壤中重金属的分布规律

本文选择提钒炼钢厂内部分土壤为研究对象,测定了重金属元素（镉、铜、铬、铅、锌）的含量,并与样品粒度大小的关系进行了探讨,结果表明金属（铜、铬、铅、锌、镉）的浓度最大值出现在粒径较小（100目或160目）的样品中,同时将测定结果与土壤环境质量标准比较,结果表明镉、锌存在污染,其余元素均未超标。     

TOA-MIBK萃取火焰原子吸收法同时测定土壤及蔬菜中铅镉

用氢氟酸、硝酸、高氯酸消化土壤样品，干灰化法消解蔬菜样品，用相对TOA-MIBK系统萃取，火焰原子吸收光谱法在同一条件下测定土壤、蔬菜中的铅、镉。在选定条件下，测得土壤铅、镉的相对标准偏差分别为2．3％～4．4％和3．0％～4.3％，蔬菜铅、镉的相对标准偏差分别为2．9％～4．5％和2．6％～4．5％；土壤铅、镉的回收率分别为96％～104％和95％～101％，蔬菜铅、镉的回收率分别为93％～102％92％104％。由测定结果得出离公路越近，蔬菜、土壤铅、镉含量越高。     

Hazard and Effects of Pollution by Lead on Vegetable Crops

Lead (Pb) contamination of the environment is an important human health problem. Children are vulnerable to Pb toxicity; it causes damage to the central nervous system and, in some extreme cases, can cause death. Lead is widespread, especially in the urban environment, and is present in the atmosphere, soil, water and food. Pb tends to accumulate in surface soil because of its low solubility, mobility, and relative freedom from microbial degradation of this element in the soil. Lead is present in soil as a result to weathering and other pedogenic processes acting on the soil parent material; or from pollution arising caused by the anthropogenic activities; such as mining, smelting and waste disposal; or through the adoption of the unsafe and unethical agricultural practices such as using of sewage sludge, and waste water in production of vegetable crops or cultivation of vegetables near highways and industry regions. Lead concentrations are generally higher in the leafy vegetables than the other vegetables. Factors affecting lead uptake included its concentration in the soil, soil pH, soil type, organic matter content, plant species, and unsafe agriculture practices. Generally, as Pb concentration increased; dry matter yields of roots, stems and leaves as well as total yield decreased. The mechanism of growth inhibition by lead involve: a decrease in number of dividing cells, a reduction on chlorophyll synthesis, induced water stress to plants, and decreased NO ₃ ^- uptake, reduced nitrate and nitrite reductase activity, a direct effect of lead on protein synthesis, a decrease on the uptake and concentration of nutrients in plants. The strategies to minimize Pb hazard can be represented in: (a) Phytoremediation, through natural plants are able to bio-accumulate Pb in their above–ground parts, which are then harvested for removal such as, using Indian Mustard (Brassica juncea), Ragweed (Ambrosia artemisiifolia), Hemp Dogbane (Apocynum cannabium), or Poplar trees, which sequester lead in its biomass. (b) Good and ethical agricultural practices such as cultivation of vegetables crops as far from busy streets or highways and industry regions as well as nonuse of sewage sludge and waste water in cultivated soils. (c) Increasing the absorptive capacity of the soil by adding organic matter and humic acid. (d) Growing vegetable crops and cultivars with a low potential to accumulate lead, especially in soils exposed to atmospheric pollution. (e) Washing of leafy vegetables by water containing 1 % vinegar or peeling roots, tubers, and some fruits of vegetables before consumption may be an important factor in reducing the lead concentration.     

我国重金属污染土壤的利用研究

检测了重金属污染地区粮食、蔬菜、水果等不同作物的重金属含量。结果表明,这3类作物对高背景值耕地土壤中有害元素吸收能力的顺序为:蔬菜粮食水果。同一地区不同地块采样点土样中重的金属含量有所差异,同一有害元素在不同作物中的积累特性不同,不同作物种类对高背景值元素的吸收差异较大,为合理开发利用被重金属污染的土地资源提供了理论依据。     

Weathering of lead bullets and their environmental effects at outdoor shooting ranges

Lead contamination at shooting range soils is of great environmental concern. This study focused on weathering of lead bullets and its effect on the environment at five outdoor shooting ranges in Florida, USA. Soil, plant, and water samples were collected from the ranges and analyzed for total Pb and/or toxicity characteristic leaching procedure (TCLP) Pb. Selected bullet and berm soil samples were mineralogically analyzed with X-ray diffraction and scanning electron microscopy. Hydrocerussite [Pb3(CO3)2(OH)2] was found in both the weathered crusts and berm soils in the shooting ranges with alkaline soil pH. For those shooting ranges with acidic soil pH, hydrocerussite, cerussite (PbCO3), and small amount of massicot (PbO) were predominantly present in the weathered crusts, but no lead carbonate mineral was found in the soils. However, hydroxypyromorphite [(Pb10(PO4)6(OH)2] was formed in a P-rich acidic soil, indicating that hydroxypyromorphite can be a stable mineral in P-rich shooting range soil. Total Pb and TCLP Pb in the soils from all five shooting ranges were significantly elevated with the highest total Pb concentration of 1.27 to 4.84% (w/w) in berm soils. Lead concentrations in most sampled soils exceeded the USEPA's critical level of 400 mg Pb kg(-1) soil. Lead was not detected in subsurface soils in most ranges except for one, where elevated Pb up to 522 mg kg(-1) was observed in the subsurface, possibly due to enhanced solubilization of organic Pb complexes at alkaline soil pH. Elevated total Pb concentrations in bermudagrass [Cynodon dactylon (L.) Pers.] (up to 806 mg kg(-1) in the aboveground parts) and in surface water (up to 289 microg L(-1)) were observed in some ranges. Ranges with high P content or high cation exchange capacity showed lower Pb mobility. Our research clearly demonstrates the importance of properly managing shooting ranges to minimize adverse effects of Pb on the environment.     

宁波市鄞州区农作物农药残留现状与控制对策

对鄞州区种植的稻谷、叶菜类、水果类、豆类、茄果类和块茎类农产品按月进行了411个批次抽样,按照国家相关规定对22个农药项目进行了检测。检测结果发现样本农药项目检出率为0.3%,农产品农药残留合格率97.82%,农药残留检出项目中88.89%是杀虫剂。超出农药残留标准的样本主要是5-10月的青菜,叶菜类超标样本率达到3.72%。农药残留超标样本在平原、滨海地区种植散户中有发现,而在山区各规模农户中均有发现。小学文化程度农户样本农药残留超标率高达4.50%,是大学文化程度农户样本农药残留超标率的6.16倍。为了降低鄞州区农作物农药残留率,提出5方面的控制对策。     

Levels of lead in blood in residents of Kuwait

Following an examination of blood samples from 1000 persons from Kuwait, a number of important differences in the levels of lead in the blood were noted. There were significant differences between the sexes living in the same residential area. Certain significant lead in blood differences were also found between females and males who dyed their hair, and between smokers and non-smokers. Lead in blood concentrations were also tested for the various blood groups of the respondents. It was noted that O⁺ blood group respondents were found to have higher lead levels than those of other major blood groups.     

降低蔬菜中硝酸盐含量的途径及其机制

蔬菜是一种喜硝,富氮的作物,所以蔬菜中硝酸盐含量较高。目前,由于偏施大量氮肥,造成蔬菜,特别是叶菜内硝酸盐含量大大超过健康标准。因此在保证高产的前提下,降低硝酸盐含量,提高品质,是迫切需要解决的问题。大量的研究表明,影响蔬菜中硝酸盐含量的因素既有内部的（品种等）,也有外部的（肥料,光照等）。本文对降低蔬菜中硝酸盐含量的途径及其机制作一综述。     

Distribution of lead in relation to size of airborne particulate matter in Islamabad, Pakistan

Airborne particulate matter (PM) collected from two sampling stations in Islamabad, Pakistan, was analyzed for lead content and size gradation. A high volume air sampler was used to trap particulates on glass fiber filters for 8-12 h on a daily basis. Lead was estimated using a nitric acid digestion based AAS method on 44 samples from station 1 and 61 samples from station 2. Particle size fractions were categorized as <2.5, 2.5-10, 10-100 and >100 microm. The correlation between lead concentration and particle size was investigated. The results from two stations indicated average airborne lead concentrations of 0.505 and 0.185 microg/m3. Enhanced levels of lead were measured at a maximum of 4.075 microg/m3 at station 1 and 4.000 microg/m3 at station 2. PM < 2.5 and PM > 100 were found to constitute the local atmosphere in comparable proportions. A comparison of the lead levels is made with the existing permissible levels of this element laid down by different international agencies.     

火焰原子吸收光谱法测定模拟尘铅中铅的前处理方法探讨

分别用酸煮法和索氏提取法对模拟尘铅样品进行前处理,采用火焰原子吸收光谱法测定,方法线性范围0.08~1.50 mg/L,检出限为0.025 mg/L。对两种前处理效果作了比较,结果表明,采用酸煮法,6次重复测量的相对标准偏差小于2%,加标回收率为90.0%~102%;索氏提取法受装置影响,提取效率不稳定,6次重复测量的相对标准偏差小于11%,加标回收率为81.5%~82.6%,酸煮法的效果优于索氏提取法。