锡铅焊料的顺序扫描等离子发射光谱分析

1 引言 锡铅焊料样品用微波-特氟隆高压罐消解。用ICP-AES对高含量Sn、微量Cu、Zn等共11个元素进行测定。本方法比传统的分析法(涉及滴定法、紫外可见分光光度法、原子吸收分光光度法等)快速、简便,精密度与准确度也完全符合在线分析要求。     

铅基合金的溶解及铅的快速测定

铅基轴承合金因为磨擦阻力小、贴服性优良、铸造性能好等优点广泛用于中小负荷机械设备的轴瓦上。然而铅基合金在用酸溶解[1] 、稀释时极易产生沉淀 ,给分析带来困难。本文研究了用盐酸 硝酸混合酸溶解试样 ,加一定量的氯化钠防止铅析出 ,用NaCl+HCl稀释液稀释 ,在微酸性溶液中 ,用EDTA容量法[2 ] 测定铅的含量。该铅基制备液还可同时测定其中的锡、铜。1　试验部分1.1　主要试剂酒石酸溶液 :30 0 g·L- 12 ,4 二硝基酚指示剂 :2 g·L- 1的乙醇溶液六次甲基四胺缓冲溶液 :称此试剂 4 0 g溶于10 0ml水中 ,加浓盐酸 10ml,调至 pH≈ 5 .…     

铅硼聚乙烯屏蔽材料中总硼的测定

试样用稀硝酸溶解以除去大部分铅,经过滤后不溶物用碳酸钠加硝酸钠进行融熔。熔块用稀硝酸浸取,分取部分此母液,在pH 3.0的条件下通过离子交换柱分离除去残留在溶液中的铅,以pH 3.0的硝酸溶液淋洗分离柱,在淋出液中用常规的碱滴定法测定其总硼量。测定结果与蒸馏法的结果一致,方法的回收率为94%~106%,相对标准偏差(RSD)值为0.77%。     

铅精矿中铅锌铁的联合测定

通常铅精矿的分析是依据国家标准ＧＢ８１５２－８７［１］进行的,但此方法未涉及铅精矿中二氧化硅铅锌铁的联合测定。为适应商检工作的需要,我们在实验基础上提出铅精矿中二氧化硅铅锌铁的联合测定方法,实现了铅精矿的快速分析,解决了国家标准中没有二氧化硅铅锌铁的含量连续测定方法的问题。１　实验部分１．１　试剂硝酸;高氯酸;硫酸;乙醇;乙酸－乙酸铵缓冲溶液（称乙酸铵２９８ｇ溶于水中,加入冰乙酸６．９ｍＬ;用水稀释至１Ｌ）;体积分数为４０％的氢氟酸溶液;抗坏血酸;氯化铵;体积分数为２０％的过硫酸铵溶液;１＋１氨…     

火焰原子吸收光谱法快速测定汽油中的铅

１　引　言四乙基铅是汽油中常用的抗爆剂。由于铅会造成严重的环境污染，近年来，四乙基铅在汽油中的使用日益受到严格限制，所以建立测定汽油中铅的简便的分析方法是非常重要的。现有测定汽油中铅的方法是容量分析法，需要经过萃取、蒸发、氧化、溶解等步骤处理油样，较为繁琐。本文使汽油与表面活性剂聚乙二醇辛基苯基醚（ＯＰ）、正丁醇和水形成微乳液后直接进样进行火焰原子吸收测定，该法具有简单、快速、准确的特点。２　实验部分２．１　主要仪器及试剂　ＷＹＸ－４０１型原子吸收分光光度计（沈阳分析仪器厂），铅空心阴极灯，铅标…     

总脂肪与铅

虽然饮食脂肪作为影响铅吸收的一个决定性因素已引起许多人的兴趣 ,但这方面的资料仅限于动物实验研究。Barltrop ( 1 975 )观察到 ,铅的吸收与饮食脂肪的数量和种类有关。当大鼠饲料中的玉米油含量从 5 %增加40 %时 ,可使大鼠几种组织中的铅含量增加 7～ 1 4倍。Quarlerman ( 1 977)也发现 ,铅吸收的程度随脂肪种类而变 ,当卵磷脂与胆汁盐和少量胆碱混合时 ,增加了铅的吸收 ,但少量卵磷脂的重要性仍有疑问。Ku ( 1 978)在对幼年大鼠和成年大鼠进行的 1 0周研究中发现 ,摄取醋酸铅或铅与磷脂的络合物 ,大鼠肾、肝、脑和股骨中的铅含量相近…     

EDTA滴定法快速测定铅基合金中铅

铅基轴承合金因为磨擦阻力小、贴服性优良、铸造性能好等优点广泛用于中小负荷机械设备的轴瓦上。然而铅基合金在用酸溶解、稀释时极易产生沉淀,给分析带来困难。铅基试样的溶解是铅基各元素分析的关键。本文着重研究了用盐酸-硝酸混合酸溶解试样,加入一定量氯化钠防止铅析出,     

总膳食与铅

禁食期摄取铅的吸收率显著高于铅和食物同时摄取的吸收率。Rabinowitz用铅示踪剂做试验 ,发现成年男子在无食物摄取时 ,有 3 5 %的铅被吸收 ,而同食物一起摄取仅吸收 8 2 %。Blake ( 1 983 )和Flannagan ( 1 982 )也证明 ,无论是成年男子或成年女子 ,禁食期或饥饿一夜后摄取的铅有较大部分被吸收。儿童禁食是否增加铅吸收 ,目前尚缺乏数据 ,但由于儿童比成人更容易饥饿 ,推想儿童的禁食 /非禁食铅滞留可能比成人更重要。纤维素和果胶可使肠道中的铅沉淀 ,减少吸收并促使排出。但乳糖可引起组织中铅滞留增加 ,血液和骨骼的最高铅浓度可分别…     

Development of candidate reference materials for the measurement of lead in bone

The production of modest quantities of candidate bone lead (Pb) reference materials is described, and an optimized production procedure is presented. The reference materials were developed to enable an assessment of the interlaboratory agreement of laboratories measuring Pb in bone; method validation; and for calibration of solid sampling techniques such as laser ablation ICP-MS. Long bones obtained from Pb-dosed and undosed animals were selected to produce four different pools of a candidate powdered bone reference material. The Pb concentrations of these pools reflect both environmental and occupational exposure levels in humans. The animal bones were harvested post mortem, cleaned, defatted, and broken into pieces using the brittle fracture technique at liquid nitrogen temperature. The bone pieces were then ground in a knife mill to produce fragments of 2-mm size. These were further ground in an ultra-centrifugal mill, resulting in finely powdered bone material that was homogenized and then sampled-scooped into vials. Testing for contamination and homogeneity was performed via instrumental methods of analysis.

Determination of chromium, cadmium and lead in food-packaging materials by axial inductively coupled plasma time-of-flight mass spectrometry

Inductively coupled plasma mass spectrometry (ICP-MS) with a time-of-flight (TOF) analyser was used for the determination of chromium, cadmium and lead in six food-packaging materials (paper and paper board). The samples (0.20-0.25 g) were digested in concentrated nitric acid in a high pressure microwave oven at 180 °C within 15 min. Two different plasma conditions were applied: cool plasma conditions (0.76 kW; 0.85, 0.89 and 15.5 l min⁻¹ nebuliser, auxiliary and plasma gas flow rate, respectively) for the determination of chromium and normal plasma conditions (1.21 kW; 0.66, 0.68 and 13.6 l min⁻¹ nebuliser, auxiliary and plasma gas flow rate, respectively) for the determination of cadmium and lead. External calibration was used in combination with rhodium (40 ng g⁻¹) as an internal standard. The detection limits (DL = 3S.D./sensitivity) under the conditions used corresponded to 0.01 ng g⁻¹ (), 0.06 ng g⁻¹ (), 0.07 ng g⁻¹ (), 0.03 ng g⁻¹ () and 0.02 ng g⁻¹ ( and ). The precision (R.S.D.) for six replicate determinations (10 s integration time) of 1 and 10 ng g⁻¹ of each analyte varied from 0.72% () to 4.43% (). The contents of chromium, cadmium and lead in the examined materials were evaluated using the signals of , and . They were in the range: 0.25-0.50 μg g⁻¹ for Cr, not detected (nd) to 0.12 μg g⁻¹ for Cd and 0.28-0.35 μg g⁻¹ for Pb in paper and 0.50-0.64 μg g⁻¹ for Cr, nd to 0.09 μg g⁻¹ for Cd and 0.67-0.99 μg g⁻¹ for Pb in paper board.     

Determination of lead in environmental reference materials (plant materials) by slurry-ETA-AAS

Slurry-ETA-AAS is used to determine lead in plant materials. The stability of the slurry was studied and it was shown that, when NH₄H₂PO₄ modifier is added, the shape of the time resolved absorbance signal for the sample and the standards is similar and the calibration line obtained using aqueous standards is parallel to the standard addition line. Results obtained for several reference materials (lead contents between 6.1 and 64.4 g/g) were in good agreement with the certified value, the relative standard deviation being 3–9%.     

Determination of cadmium and lead in reference materials by volatile species generation with in situ trapping flame atomic absorption spectrometry

The analytical performance of coupled volatile species generation-integrated atom trap (VSG-IAT) atomizer flame atomic absorption spectrometry (FAAS) system was evaluated for determination of Cd and Pb in reference materials. Lead using formation of PbH₄ and Cd⁰ vapors are atomized in air-acetylene flame-heated IAT. A new design of VSG-IAT-FAAS hyphenated technique that would exceed the operational capabilities of existing arrangements (a water-cooled single silica tube, double-slotted quartz tube or an “integrated trap”) was investigated. A dramatic improvement in detection limit was achieved compared with that obtained using either of the above atom trapping techniques separately. The concentration detection limits, defined as 3 times the blank standard deviation (3σ), were 0.05 and 0.40 ng mL^− 1 for Cd and Pb, respectively. For a 120 s in situ pre-concentration time, sensitivity enhancement compared to flame AAS, was 500 and 575 folds for Cd and Pb, respectively, using volatile species generation-atom trapping technique. The sensitivity can be further improved by increasing the collection time. The precision, expressed as RSD, was 4.4% and 4.1% (n = 6) for Cd and Pb, respectively. The designs studied include slotted tube, single silica tube and integrated atom trap-cooled atom traps. The accuracy of method was verified using certified reference materials (PLANTS 3 and IAEA/W-4) by standard addition calibration technique. The measured Cd and Pb contents in two reference materials were in satisfactory agreement with the certified values.     

X射线荧光光谱法测定聚合物材料中铅和镉

提出了X射线荧光光谱法测定聚合物材料中铅和镉的方法。将粒径小于4mm的样品颗粒置于样品杯中,保持样品厚度大于16mm,加盖后按仪器工作条件进行测定。铅和镉的线性范围依次在1 033μg.g-1和980μg.g-1以内,检出限依次为0.31μg.g-1和0.69μg.g-1。方法用于分析标准物质(ERM-EC680k和ERM-EC681k),测定值与认定值相符。     

火焰原子吸收法测定铅锌矿中微量镓

将样品中的硫化物用HNO3氧化为硫酸盐后,再用HNO3、HF、H2SO4进一步溶解,在6mol/LHCl介质中用乙酸丁酯萃取镓,水反萃取后,用火焰析子吸收法测定Ga,该法检出限为0．80μg/mL,相对标准偏差为2．1％,用该法测得国家一级标准品的结果均与推荐值相符。     

氢化物发生-原子荧光法测定绞股蓝中痕量铅

建立了以重铬酸钾为氧化剂、碱性铁氰化钾为络合剂, 丙二酸为掩蔽剂, 在盐酸介质中进行铅的氢化物发生的反应体系. 样品经HNO3-H2O2体系高压消解后, 采用断续流动氢化物发生器, 对测定铅的各种条件进行了优化和探讨. 在选定条件下, 方法检出限为3.76×10-7 g/L, 线性范围为0.01～2.00 ×10-4 g/L, 相对标准偏差为1.3%. 方法用于绞股蓝中铅的测定, 回收率为90.5%～101.4%.     

Determination of lead in aluminum and magnesium antacids using electrothermal atomic absorption spectrometry

This paper proposes a method for the determination of lead in aluminum and magnesium antacids employing electrothermal atomic absorption spectrometry (ET AAS). The pyrolysis and atomization temperatures established during the optimization step were 700 and 2200 °C, respectively, using phosphate as the chemical modifier. Under these conditions, a characteristic mass of 25 pg, and limits of detection and quantification of 0.40 and 1.35 μg L⁻¹, respectively were obtained. Some experiments demonstrated that the calibration can be performed employing the external calibration technique using aqueous standards. The precision expressed as relative standard deviation (RSD %) was 4.03% for an antacid sample with lead concentrations of 284.5 μg L⁻¹. The proposed method was applied for the determination of lead in five antacid samples acquired in Salvador City, Brazil. The lead content was varied from 87 to 943 μg g⁻¹. The samples were also analyzed after complete dissolution by inductively coupled plasma mass spectrometry (ICP-MS). No statistical difference was observed between the results obtained by both of the procedures performed.     

Determination of lead in environmental water by a backward light scattering technique

An optical fiber assembly developed in our laboratory, which is based on detecting backward light scattering (BLS) signals, is now applied to detect the lead content in environmental samples. Due to effectively eliminating the interference of reflected light, this BLS signals based detection assembly can be used to determine analyte directly. In HAc-NaAc buffer medium (pH 4.8), the interaction of lead and sodium tetraphenylboron (TPB) in the presence of polyethylene glycol (PEG) yields large particles of ternary complex, resulting in strong enhanced backward light scattering (BLS) signals characterized at 371 nm. By measuring the BLS signals with the homemade optical fiber assembly coupled with a common spectrofluorometer, we found that the enhanced BLS intensity is proportional to lead content over the range of 0.03-1.0 μg ml⁻¹ with the limit of determination (LOD) of 2.6 ng ml⁻¹. Three artificial water samples containing various coexistent substances were detected with the recovery of 90.1-107.5%. Standard addition method was used to detect the lead content in drink tap water, and found that the lead is hardly to detect due to too low content. Prior enrichment should be made in order to detect river water samples, and it was found that the content of lead in Jialing River at Bebei Dock is about 14 ng ml⁻¹, identical to the results using inductively coupled plasma atomic emission spectrometry (ICP-AES).     

Na2EDTA滴定法测定粗二氧化碲中铅含量

建立了用氢溴酸消除锑、砷、锡干扰,用硫酸将铅形成硫酸铅沉淀,再用EDTA络合滴定法测定粗二氧化碲中铅量的方法。试样用硝酸、盐酸溶解,用硫酸沉淀铅,氢溴酸消除锑、砷、锡的干扰后,过滤分离其他共存元素,以乙酸-乙酸钠缓冲溶液溶解硫酸铅沉淀,在pH=5.0～6.0时,以二甲酚橙作指示剂,用Na_2EDTA溶液滴定溶液中铅含量。实验结果表明,氢溴酸加入量为15mL,酒石酸加入量为10mL,沉淀体积为50～60mL,沉淀时间1h以上时,方法相对标准偏差(RSD)在0.10%～1.1%,加标回收率为97.1%～102%,满足粗二氧化碲中铅量的生产控制检测要求。