微量铅,镉极谱法连续测定

１　引　言铅镉催化极谱单项测定均已有报道，但对于微量铅镉连续测定尚未得到很好的解决。作者在实验中发现Ｗ．Ｃｈｒｉｓｍａｎｎ提出的仅用于测定铅的Ｐｂ－ＫＩ－Ｖ（Ⅳ）－Ｖｃ－ＨＡｃ体系中，用于铅镉连续测定，则镉波太小，只能查见。当加入少量ＯＰ试剂，可使镉波大幅度增高，同时加入少量吡啶，更有利于铅镉波形稳定，并且底液有适宜乙醇，可以抑制底液波及残余电流，提高铅铜的检出限，从而很好地解决了微量铅、锅的连续测定问题。本文建立了连续测定的适宜条件，详细研究了共存离子的干扰情况。该法具有简便、快速、灵敏度高、…     

石墨炉原子吸收光谱法测定全血中铅的方法改进

针对不同的石墨管测定全血中铅时，用铅标准溶液制作的标准曲线和以全血为基体制作的标准工作曲线斜率的不一致，提出以磷酸氢二铵、磷酸氢二钠和硝酸铵作基体改进剂，以全血为基体制作标准工作曲线来测定全血中铅含量的方法。试验表明，此法基本消除了全血基体对血铅测定的影响，适应各种石墨管，可快速、准确地测定全血中铅。     

用MeSO－四（3，5－二溴－4－羟基苯基）卟啉试剂二阶导数光度法测定痕量铅

用ＭｅＳＯ－四（３，５－二溴－４－羟基苯基）卟啉试剂二阶导数光度法测定痕量铅李在均，潘教麦，徐钟隽（华东师范大学化学系，上海２０００６２）关键词：二阶导数光度法，铅的测定，人发Ｔ（ＤＢＨＰ）Ｐ是铅的高灵敏显色剂￣［１］，已用于矿样等样品中铅的测定。￣...     

流动注射在线共沉淀HG-AFS测定痕量铅

建立了流动注射在线共沉淀HG-AFS测定痕量铅的分析方法。方法基于铅在碱性介质中与氢氧化镁共沉淀，沉淀收集在锥形沉淀腔中，用HCl溶洗沉淀和NaBH4反应，产生的氢化物被载气引入原子化器中进行测定。测定铅的RSD为3％(5ng/mL，n=10)，检出限为0．01ng。检出限较直接进样降低了11倍。对国家标准物质中铅的测定结果与标准值相符。     

电感耦合等离子体质谱法测定水泥样品中的铅同位素比值

研究和讨论了用电感耦合等离子体质谱仪(ICP—MS)测定铅的同位素比值测定时，影响测试结果的准确度和精密度的主要因素及其优化过程。在优化后的仪器分析条件下，测定5μg/L的NIST SRM981自然丰度铅同位素标准溶液的各对铅同位素比值，获得的^207Pb／^206Pb分析精度可优于0．1％。在该条件下测定了14个不同的水泥粉样品中的铅同位素比值，结果显示：铅的同位素比值分析技术可以用来示踪环境监测样品的铅污染源。     

4-(2-吡啶偶氮)间苯二酚显色-分光光度法测定无机铅和烷基铅

１引言铅是公路两侧大气监测中重点控制的重金属元素。不同形态铅的毒性差异很大，其中三烷基铅的毒性最大。我国目前尚无大气中烷基铅的监测方法，用分光光度法进行铅形态分析也未见报道。本文报道了４－（２－吡啶偶氮）间苯二酚（ＰＡＲ）显色－分光光度法测定无机铅、二乙基铅和三乙基铅的方法，有较好的回收率和精密度，可用于测定大气飘尘中的烷基铅。二实验部分２．１仪器及试剂７２２型分光光度计，ｐＨＤ－１１型数字式酸度计。０．２４０ｍｍｏｌ／Ｌ二乙基铅（ＰｂＥｔ２）、三乙基铅（ＰｂＥｔ３）和０．４８０ｍｍｏｌ／Ｌ无机…     

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…     

头发微量元素及钙含量测定的应用价值评价

以125例2～5岁儿童为对象，测定其全血和头发铅、锌、铁、钙含量；以全血铅、锌、铁、钙含量为标准，应用诊断试验评价方法评价头发铅、锌、铁、钙测定的应用价值。结果表明，头发铅测定的灵敏度可达88．3％，应用串联试验，头发铅测定的特异度可提高至81．8％，阳性预测值达69．6％，阴性预测值达78．8％。头发锌测定的灵敏度可达86．1％，特异度为52．4％，阳性预测值75．6％，阴性预测值为68．8％。头发铁测定的灵敏度为72．0％，特异度为77．5％，阳性预测值为83．6％，阴性预测值为63．3％，头发钙测定的灵敏度为78．9％，特异度为69．1％，阳性预测值为69．8％，阴性预测值为78．4％。锌缺乏、铁缺乏、钙缺乏，或铅负荷过高，或数种微量元素缺乏及铅中毒并存是当前严重影响儿童健康成长的常见原因。运用现代检测技术早期发现微量元素缺乏及铅中毒患儿并及时采取防治措施对促进儿童正常生长发育至关重要。头发样品容易采集、运送和保存，因此头发微量元素含量测定适合在中小城镇及农村使用。但其应用价值应进行科学评价。     

原子荧光光谱测定化妆品中痕量铅

介绍氢化物发生－原子荧光光谱法对化妆品中铅含量的定量分析方法，并研究原子荧光光谱测定铅的分析条件。方法检出限低，精密度高，准确性好，可用于测定化妆品中的痕量铅。     

简易测定发中微量元素铅的方法实验与探讨

通过对简易测定发铅的方法实验，研究与探讨，提出纸色谱法是简易测定发中微量元素铅的较好方法，该法简捷，快速，分析样品量大，成本低，无污染，有推广普及价值。     

喷流型发生器、氢化物-原子吸收光谱法测定岩石、矿物中的铅

本文采用喷流型连续氢化物发生器,氢化物-火焰原子吸收光谱法对岩石、矿物中微量铅的测定条件进行了研究。用铁氰化钾作为铅的氧化剂,草酸为干扰抑制剂,于217.0nm波长,测得铅的特征浓度为0.012μg/ml(1％吸收)。相对标准偏差(对0.6μg/ml Pb)为0.97％。     

Natural mineral sorbents for chemical and microbiological purification of potable water

The role of a number of rocks (shungite, glauconite fossil rock, flint) in a chemical and microbiological purification of water was estimated. On the basis of a shungite-dolomite module a simple method for a widescale manufacture of chemically and microbiologically pure potable water with conditionated content of mineral matters was developed.     

The determination of lead in 13 USGS standard rocks

Lead was determined in 13 U.S. Geological Survey standard rocks by graphite furnace atomization and atomic-absorption spectrometry after extraction of lead with diethylammonium diethyldithiocarbamic acid. An analysis of variance of the results obtained from a random sampling of three different bottles of each standard rock showed no heterogeneity among bottles, at the F(0.95) level, for a 100-mg sample-size. The relative error of the method, based on the standard deviation of the mean within bottles, was generally less than 10%.     

Determination of lead in carbonate rocks by carbon-furnace atomic-absorption spectrometry after dissolution in nitric acid

A simple and rapid method for the determination of 1-100 ppm of lead in carbonate rocks is described. Dissolution of the rock samples in 10% v v nitric acid is shown to give precise and accurate results even though silicates in the samples remain undissolved. A more time-consuming but complete dissolution of the sample with hydrofluoric acid may be used if preferred. The increase in sensitivity and freedom from matrix interference obtained by the use of a carbon-furnace atomizer eliminate the necessity for preconcentration of the lead, saving time and preventing errors from contamination or losses derived from inefficient extraction procedures. The detection limit and precision of the method are 0.4 ppm and 6% (relative standard deviation at the 3-ppm lead level) respectively and accurate results were obtained for the analysis of standard rock samples.     

Source apportionment of atmospheric carbonaceous particulate matter based on the radiocarbon

A method was established to quantitatively estimate sources of atmospheric carbonaceous matter, using a combination of radiocarbon technology, linear regression of organic carbon (OC) -K⁺ and elemental carbon (EC) tracer method. Fractional contributions of fossil fuels, biomass burning, biogenic secondary organic carbon (BSOC) and soil dust to the atmospheric size-resolved carbonaceous matters in Shanghai suburb were estimated using this new method. The fossil carbon contributed most of the OC in particles smaller than 0.49 μm, and its fraction decreased with the increase of particle size. Biomass burning contributed 17–28 % to the OC. The BSOC contributed comparable proportions to the OC in particles smaller than 3.0 μm with the biomass burning, but larger in the particles lager than 3.0 μm. The soil dust contributed least fraction to the OC of each size with a proportion of 2–13 %. The biomass burning and fossil sources shared comparable fraction of the EC in all size range.     

Using magnesium oxide nanoparticles in a magnetic field to enhance oil production from oil-wet carbonate reservoirs

Enhanced oil production can maximise yield from depleted reservoirs, and in the face of dwindling global oil reserves can reduce the need for exploratory drilling during the transition away from fossil fuels. A hybrid technique, merging a magnetic field (MF) and magnesium oxide (MgO) nanoparticles (NPs), was investigated as a potential method of enhancing oil production from oil-wet carbonate reservoirs. The impact of this hybrid technique on rock wettability, zeta potential, and interfacial tension was also investigated. Displacement experiments were carried out on oil-wet Austin chalk – a laboratory carbonate rock analogue – using MgO NPs in deionized water (DW) and salt water (SW), in the presence of an MF up to 6000 G in strength. It was found that the addition of MgO NPs to DW before the spontaneous imbibition of the solution into initially oil-wet rock samples increased the recovery factor (RF, defined as the volume of oil recovered divided by the initial oil in place). For 0.005 wt% and 0.0025 wt% MgO NPs mixed in DW, the RF was 12.5% and 15.9% respectively. When DW was replaced with SW as the imbibing fluid, the RF increased by a further 0.7% of initial oil in place for the 0.0025 wt% MgO NPs. This additional increase in oil recovery was attributed to the presence of potential determining ions, which made the rock more water-wet. To avoid pore-clogging and thus the limited ingress of the solution into the rock, the NPs’ concentration was kept low. This hybrid technique is a cleaner alternative to conventional enhanced oil recovery techniques and will enable oil industries to produce oil more efficiently from existing reservoirs: when used in conjunction with Carbon Capture and Storage (CCS), this provides a useful short to medium-term option to support energy production during the transition to net zero.     

毛细管电泳-电感耦合等离子体质谱联用测定海藻中铅形态化合物

建立了毛细管电泳( CE)与电感耦合等离子体质谱( ICP-MS)联用技术测定铅离子( PbⅡ)、三甲基铅(TML)和三乙基铅(TEL)3种不同形态铅化合物的方法,以及海藻中不同形态铅化合物的提取技术,实现了海藻中3种铅形态化合物的定性定量分析。结果表明：以70 mmol/L H3BO3-17.5 mmol/L Na2B4O7(pH 8.90)为缓冲溶液,在最佳CE-ICP-MS条件下3种铅化合物20 min内可实现有效分离,重现性较好,迁移时间RSD﹤4%,峰面积的RSD﹤5%;在10~200μg/L 范围内3种铅化合物线性较好,相关系数大于0.90; PbⅡ、TML和TEL的CE-ICP-MS检出限(3S/N,以Pb计)分别为0.091,0.023和0.030μg/L;采用分步提取海藻中Pb元素,提取率高达80%以上,以藻体为基底 PbⅡ, TML 和 TEL 回收率分别为103.6%,95.7%和90.6%;通过检测紫菜和海带中铅含量,结果显示藻体内Pb主要以PbⅡ形式存在。本方法具有简单、高效、样品消耗量少等优点,可为海藻及其它海产品的质量控制提供技术支撑。     

微波消解–石墨炉原子吸收法测定药食两用中药材中的铅

建立测定药食两用中药材中铅含量的微波消解–石墨炉原子吸收光谱分析方法。样品经微波消解后,以2%磷酸二氢铵为基体改进剂,用石墨炉原子吸收法测定药食两用中药材中的铅含量。在2~40μg/L范围内,铅的质量浓度与吸光度呈良好的线性关系,线性相关系数r大于0.999,检出限为5μg/kg。加标回收率为94.0%~105.5%,测定结果的相对标准偏差小于5.0%(n=6)。该方法操作简便快速,准确度较高,基体干扰小,适合药食两用中药材中铅的检测。     

电感耦合等离子体发射光谱(ICP-OES)法测定含稀土磷矿中钛

为了准确测定含稀土磷矿石中钛的含量,采用两种溶样方法对磷矿进行处理,用电感耦合等离子体发射光谱(ICP-OES)法对磷矿中钛进行测定。实验表明,不进行基体匹配的标准曲线法不适合磷矿中钛的分析,采用基体匹配的标准曲线法时又难以制得与其各组分含量相似的校准溶液。用能有效消除样品本身基体干扰的标准加入法进行测定,分析结果的相对标准偏差小于2.0%,碱熔法的加标回收率为98.48%,酸溶法的加标回收率为104.4%,检测结果可靠,适合于磷矿中钛的分析。     

Postdiagenetic Changes in Kerogen Properties and Type by Bacterial Oxidation and Dehydrogenation

A significant part of organic carbon found on the earth is deposited as fossil organic matter in the lithosphere. The most important reservoir of carbon is shale rocks enriched with organic matter in the form of kerogen created during diagenesis. The purpose of this study was to analyze whether the bacterial communities currently inhabiting the shale rocks have had any impact on the properties and type of kerogen. We used the shale rock located on the Fore-Sudetic Monocline, which is characterized by oil-prone kerogen type II. We were able to show that shale rock inhabited by bacterial communities are characterized by oxidized and dehydrated kerogen type III (gas-prone) and type IV (nonproductive, residual, and hydrogen-free). Bacterial communities inhabiting shale rock were dominated by heterotrophs of the Proteobacteria, Firmicutes, and Actinobacteria phyla. Additionally, we detected a number of protein sequences in the metaproteomes of bacterial communities matched with enzymes involved in the oxidative metabolism of aliphatic and aromatic hydrocarbons, which may potentially contribute to the postdiagenetic oxidation and dehydrogenation of kerogen. The kerogen transformation contributes to the mobilization of fossil carbon in the form of extractable bitumen dominated by oxidized organic compounds.