大气氟化物测定──滤膜、氟离子选择电极法研究验证报告

大气氟化物测定──滤膜、氟离子选择电极法研究验证报告武夏萍，徐新民，胡强宁，康允昌（内蒙包头市环境监测站，０１４０３０）、（内蒙包头市环境保护局）１．大气氟化物测定方法简介国内外使用的环境大气中氟化物的测定方法有：氟化物自动测定装置、双滤膜法、双纸带...     

连续分光光度法测定环境样品中砷（Ⅲ）、砷（Ⅴ）

使用硼氢化钾做还原剂、砷（Ⅲ）在ＰＨ６时还原为砷化氢，维续酸化样品至ＰＨ≤１时，砷（Ⅴ）再被还原为砷化氢。两种砷经与二乙氨基二硫代甲酸银反应生成带色络合物，实现了连续分光光度测定。两种形态砷的检测限为０．０１μｇＡｓ，对砷标准参考物质的测定合格，回收率为９７．０—１０１．６％。     

火焰、石墨炉原子吸收法测定地表水中铜和镉

对浓缩火焰原子吸收法和石墨炉原子吸收法测定地表水中痕量铜和镉的结果作了比较。试验结果表明，两种方法测定结果间无明显差异，加标回收率为88．7％～103％，可互相替代，等效使用。     

共沉富集─单缝石英管火焰原子吸收法测定水中痕量铜、铅、锌、镉

采用共沉富集与单缝石英管技术，以火焰法测定地面水、地下水中的痕量铜、铅、锌、镉，检测限分别为０．５，１．８，０．２，０．１μｇ／Ｌ，四种痕量元素１１次测定的变异系数分别２．８％，２．３％，３．１％和３．９％。     

微分脉冲伏安法测定降水中锌、镉、铅和铜

以量浓度为0．01mol/L的高氯酸为支持电解质，采用微分脉冲阳极溶出伏安法同时测定降水中的痕量Zn^2 、Cd^2 、Pb^2 和Cu^2 ．6次测定的相对标准偏差均小于5％，降水样品镉未检出。锌、铅、铜的加标回收率分别为91．5％－110．0％、91．5％－104．0％和91．0％－106．0％。该方法应用于降水中Zn、Cd、Pb、Cu痕量元素的分析，具有方法简便、快速、准确度高等特点。     

一次微波消解测定土壤中铬铜锌铅镉

测定土壤中铬、铜、锌、铅、镉多采用传统电热板加热消解方式进行样品处理，但不能同时一次消解．笔者尝试使用微波一次消解测定五种元素，试验结果令人满意．     

单柱阳离子色谱快速分析白云石中高含量钙镁

采用离子色谱法同时测定白云石中高含量钙镁，该法与目前使用的络合滴定法相比，具有准确可靠、操作简便快速、无干扰等特点。对样品测定取得了满意的结果，氧化钙与镁瓣含量分别为３１．９９％和２１．４７％，相对标准偏差分别为０．８１％和０．６５％，平均回收率分别９９．９％和１０２％。     

对酸、中、碱性土壤中有效元素用E－Na试液提取原子吸收测定的初探

对酸、中、碱性土壤中有效元素用Ｅ－Ｎａ试液提取原子吸收测定的初探王国志（云南玉溪地区环境监测站，６５３１００）①用ＥＤＴＡ－柠檬酸钠为提取液测定有效元素Ｃｕ、Ｚｎ时，最佳提取液浓度为０．１３４Ｍ。②当提取液ｐＨ值用ＮａＯＨ调到８．５左右，测定有效元素...     

原子吸收光谱法测定酸雨中K、Na、Ca、Mg方法改进

用0．1％硝酸溶液配制混合标准溶液，不加抗干扰试剂，火焰原子吸收光谱法直接测定酸雨中K、Na、Ca、Mg，方法精密度、准确度满足酸雨监测的分析要求。     

大气飘尘中碲的测定－原子荧光法

本法使用美国进口的大流量采样器采样，用国产的玻璃纤维滤膜作滤材，以硝酸、高氯酸分解，硼氢化钾还原－无色散原子荧光法对碲进行测定。本法在采样体积３６０ｍ３，最低检出浓度５．８×１０－５μｇ／ｍ３，精密度５．７－９．６％，回收率８７．０－１１０．０％，结果令人满意，适于大气飘尘中碲的测定     

Determination of Pb and Cd in road dusts over the period in which Pb was removed from petrol in the UK

It is commonly agreed that automobile exhaust has been the most important source of Pb pollution in urban areas, and that Cd may come from wear and tear of tyres. This study evaluates the fall in Pb concentrations in road dusts in Manchester as a consequence of the removal of Pb from petrol in January 2000. In the work presented here a slurry graphite furnace atomic absorption methodology for the determination of Pb and Cd in road dusts has been developed and is compared with an acid digestion method in terms of efficiency. The reproducibility and accuracy of the results obtained by acid digestion and the slurry method have been studied and a certified reference material CRM 038 was analysed to confirm the reliability of the proposed methods. Different factors were evaluated throughout this work including: (i) the effect of traffic density on Pb and Cd levels in road dust samples collected weekly during the period of May 1999 until September 2000; (ii) comparison between the Pb and Cd levels in a busy road and a residential street; (iii) the effect of distance from the source on Pb and Cd levels; The results of these experiments show a reduction in Pb levels over the sampling period. The relationship between road dust particle size and Pb and Cd concentration was also investigated in the 4-250 microns size range using the slurry method, showing that there is a relationship between metal concentration and particle size; the highest concentrations being for the smallest particle size.     

Impaction collection and slurry sampling for the determination of arsenic, cadmium, and lead in sidestream cigarette smoke by inductively coupled plasma-mass spectrometry

The slurry sampling technique has been applied for the determination of arsenic, cadmium and lead in sidestream cigarette smoke condensate (SS CSC) by inductively coupled plasma mass spectrometry (ICP-MS). The smoke collection system consists of a "fishtail" chimney in conjunction with an impaction trap and a mixed cellulose ester (MCE) backup filter for the SS CSC collection. The smoke condensates, collected at three different regions of the system (i.e. the inner wall of the chimney, the impaction trap and the MCE filter), were individually prepared and analyzed and showed that about 70 and 20% of Cd and Pb, respectively, were trapped by the impaction trap and the MCE filter with less than 5% trapped by the chimney. In contrast, about 60% of As was trapped by the impactor and a relatively high percentage of As, about 30%, was deposited onto the inner wall of the chimney. The uneven distribution of trace metals at each collection stage strongly suggested that the composition of smoke aerosol and the associated physical form of the analytes may be different. The yields of As, Cd and Pb for the sidestream cigarette smoke of the 1R4F reference cigarette were 29.5 +/- 2.4, 421 +/- 6.6 and 46.4 +/- 0.9 ng cigarette(-1)(n= 3) respectively, when the cigarette was smoked according to the smoking regime: 45 mL puff volume of 2-s puff duration at an interval of 30 s with 50% ventilation holes covered. The analytical results for the slurry sampling technique were also compared with other sample preparation techniques and show good agreement.     

Surfactant-mediated complex formation for determination of traces amounts of zinc, cadmium, and lead with 4-(2-thiazolylazo) resorcinol and chemometric methods

The partial least squares modeling is a powerful multivariate statistical tool applied to the spectrophotometric simultaneous determination of the divalent ions of zinc, cadmium, and lead based on the formation of their complexes with 4-(2-thiazolylazo) resorcinol in surfactant media. The linear concentration range for zinc, cadmium, and lead were 0.10-1.31, 0.148-1.92, and 0.148-3.70 mg L(?-1), respectively. The experimental calibration set was composed of 36 sample solutions using a mixture design for three component mixtures. The absorption spectra were recorded from 380 through 650 nm. The effect of pH on the sensitivity in determination of zinc, cadmium, and lead was studied in order to choose the optimum pH (pH = 8) for determination. The root-mean-square errors of predictions for zinc, cadmium, and lead were 0.0466, 0.0282, and 0.050, respectively. The proposed method was successfully applied for the determination of zinc, cadmium, and lead in water samples.     

Ultrasound-assisted ionic liquid-based microextraction combined with least squares support vector machines regression for the simultaneous determination of aluminum,gallium, and indium in water and coal samples

A new simple and rapid ultrasound-assisted ionic liquid-based microextraction method was applied to preconcentrate aluminum(III), gallium(III), and indium(III) ions from water samples as a prior step to their simultaneous spectrophotometric determination using least squares support vector machines regression. In the novel procedure, 1-hexyl-3-methylimidazolium hexafluorophosphate [C₆MIM][PF₆] was dispersed into the aqueous sample solution as fine droplets by ultrasonication, and the analytes were extracted into the ionic liquid phase after complexation with 1,2,5,8-tetrahydroxy anthraquinone (quinalizarine). After centrifuging, the fine droplets of extractant phase were settled to the bottom of the conical-bottom glass centrifuge tube. The detection limits for Al(III), Ga(III), and In(III) were 1.70, 2.02, and 2.06 ng mL⁻¹, respectively. The precision of the method, evaluated as the relative standard deviation obtained by analyzing a series of ten replicates, was below 3.2% for all elements. The method was successfully applied for the determination of Al(III), Ga(III), and In(III) in real samples.     

Solid phase extraction of Cd,Pb, Ni,Cu, and Zn in environmental samples on multiwalled carbon nanotubes

A simple and sensitive solid phase extraction (SPE) method on multiwalled carbon nanotubes (MWCNTs) is presented for the determination of cadmium, lead, nickel, copper, and zinc at trace levels combined with flame atomic absorption spectrometry. The effects of parameters like pH, sample volume, sample and eluent flow rates, eluent concentration, and volume and type of eluent on the recovery of trace elements was examined. The metals retained on the nanotube at pH 6.5 as α-benzoin oxime complexes were eluted by 10 mL 2 M HNO₃ in acetone. The influence of matrix ions on the developed method was also evaluated. The preconcentration factor of the method was found to be 50. The detection limits for Cd(II), Pb(II), Ni(II), Cu(II), and Zn(II) were found as 1.7, 5.5, 6.0, 2.3, and 2.4 μg L^?1, respectively. To test the accuracy of the method, the method was applied to TMDA-70 fortified lake water and Spinach 1570A standard reference materials. Addition recovery studies were applied to tap water and cracked wheat samples, and determination of the analyte elements was carried out in some food samples with good results.     

Simultaneous Determination of O- and P- Nitrophenol by First Derivative Spectrophotometry

A simple method by first derivative spectrophotometry is proposed for the simultaneous determination of o-nitrophenol and p-nitrophenol. The analytes were separated from samples by liquid-liquid extraction (pH = 7.4) as tetrabutylammonium ion pairs into the 1,2-dichloroethane organic phase and subsequently the extracts were evaluated directly by derivative spectrophotometry. Simultaneous determination of both analytes could be carried out using the zero-crossing and the graphical methods for o-nitrophenol and p-nitrophenol, respectively. The determination ranges were found to be between 0.115 to 3.00 ppm and 0.130 to 3.00 ppm for o-nitrophenol and p-nitrophenol, respectively. The relative standard deviations were in all instances less than 2.0%. The proposed method was applied to the determination of these compounds in fruit juices.     

Facile and Sensitive Spectrophotometric Determination of Synthetic Pyrithroids in Their Formulations, Water and Grain Samples

A novel reagent was introduced for the facile and sensitive spectrophotometric determination of syntheitic pyrethroids in their formulations (fenvalerate, cypermethrin and decamethrin), water and grain samples. These methods were based on the hydrolysis of synthetic pyrethroids under the alkaline conditions to form respective aldehyde groups. These groups were condensation with 3-methyl-2-benzothiazolinone hydrochloride (MBTH) to yield color derivatives having λ_max at 520 nm for fenvalerate, 516 nm for cypermethrin and 512 nm for decamethrin. The proposed method could be successfully applied for the determination of synthetic pyrethroids in their formulations, water and grain samples.     

流动注射氯化亚锡还原光度法测定水中总磷

建立了流动注射氯化亚锡还原光度法测定水中总磷的方法.改进了氯化亚锡的配制方法,优化了试验条件,方法检出限为0.02 mg/L,精密度与准确度均符合要求.应用该方法测定天然水样,分析速度加快,结果令人满意.     

水体中磺胺、四环素、喹诺酮类抗生素检测方法

建立了固相萃取-高效液相色谱-串联质谱法(SPE-HPLC-MS/MS)同时检测水体中3类15种抗生素的分析方法。水样用Oasis HLB固相萃取小柱净化富集。通过对比水样在不同pH条件下的回收率,优化了环境水样中抗生素固相萃取过程中的前处理条件。采用甲醇和0.1%甲酸溶液作为流动相,经过梯度洗脱进行分离,在HPLC-MS/MS多反应监测模式下进行定性定量分析。结果表明,环境水体中15种抗生素的检出限和定量下限分别为0.12~1.6 ng/L和0.2~3.0 ng/L,自来水加标回收率为34.9%~102.5%(pH=4)。用该方法对海河流域13个地表水水样进行了初步检测,结果表明,部分抗生素普遍存在于地表水体中。其中,磺胺甲基异NFDA1唑检出频率最高,在13个地表水样品中均有检出。     

扩散采样法测定室内空气中的BTEX

建立了扩散吸附管采样,热脱附仪和气相色谱联用测定室内空气中BTEX的监测分析方法,方法的最低检出限为0.0002mg/m3。该方法使用方便、便于携带、无需电源,且与传统的泵采样方法具有较好的可比性,适合于室内空气中BTEX的监测。