发生氢气分离离子色谱法间接测定水中硫化物

利用ＫＢＨ４在酸性条件下分解产生的氢气为载气分离水中硫化物，用ＮａＯＨ—Ｈ２Ｏ２溶液吸收Ｈ２Ｓ，并将其氧化为ＳＯ２－４，用离子色谱法测定ＳＯ２－４。方法用于各种水样中硫化物的测定，相对标准偏差为１．５８％，回收率在９０．５％到９８．２％之间。方法适用于水中硫化物的测定     

石墨炉原子吸收光谱法测定土壤中的微量砷

土壤样品经ＨＮＯ３－ＨＣＩＯ４消解处理后，采用Ｎｉ作为基体改进剂，偏振塞曼效应扣去背景，实现了砷的石墨炉原子吸收法的直接测定。该方法操作简单，干扰少，灵敏度高，砷的检测下限为０．７ｎｇ／ｍｌ，样品分析回收率９４％－１０８％，相对标准偏差５．１％。     

用恒波长同步荧光光谱法测定西班牙Galicia地区饮用水和地表水中多环芳香烃

１实验１１试剂使用了萤蒽、苯并［ａ］芘、苯并［ｂ］萤蒽、苯并［Ｋ］萤蒽、茚并－［１２３－ｃｄ］芘和苯并［ｇｈｉ］艹北标准试剂,颗粒状无水Ｎａ２ＳＯ４,正己烷和分析纯Ｈ２ＳＯ４。Ｈ２ＳＯ４在使用前用正己烷洗涤。在测定前,所有试剂的纯度都在分析条件下进...     

底质中汞的快速消解方法

底质中汞的快速消解方法王国朝，王鲁海，周春华，刘新凤（新疆乌鲁木齐市环境科研监测站，８３９０００）底质中汞的消解方法有湿法和于法两种。文献［１．２］介绍的湿法有：Ｈ２ＳＯ４－ＫＭｎＯ４电热板加热和水浴加热法；Ｈ２ＳＯ４－ＨＮＯ３－ＫＭｎＯ４电热板加热...     

火柴中总铬测定的前处理方法

火柴中总铬测定的前处理方法李华于卫东夏凯（山东济宁市环境监测站，济宁２７２１４５）经试验表明，火柴样品的前处理，以采用硫酸溶液浸泡、加热消解的方法比用硝酸的为好。其步骤：向样品锥形瓶中加１５ｍｏｌ／Ｌ（１／２Ｈ２ＳＯ４）溶液５０ｍｌ，浸泡３０ｍｉｎ...     

高效液膜分离富集测定微量铜

应用高效乳状液膜技术分离、富集水和土壤样品中微量铜（Ⅱ）．研究了流动载体（Ｐ２０４）、表面活性剂（ＳＰａｎ８０）、膜的增强剂（液体石蜡）、膜溶剂（煤油）和内相解吸剂（２．５ｍｏｌ／ＬＨ２ＳＯ４）等液膜体系，对分离富集微量铜（Ⅱ）的影响．确定了Ｓｐａｎ８０—Ｐ２０４─液体石蜡─煤油─Ｈ２ＳＯ４高效液膜体系的最佳组成和最适宜的实验条件．富集后的溶液用１－（２－吡啶偶氮）－２－萘酚（ＰＡＮ）分光光度法测定铜（Ⅱ）．用本法富集水和土壤中微铜（Ⅱ）．回收率在９９％以上。应用于测定水和土壤中的微量铜．相对标准偏差为１．２％～４．５％。     

增压溶样－冷原子荧光法测定煤样中的汞

采用增压溶样器加７：３：５的ＨＮＯ３－Ｈ２ＳＯ４－ＨＣｌＯ４混合酸处理煤样．用冷原子荧光法测定煤样中的总汞含量。该法的加标回收率为９２．７～１１２．５％，结果令人满意。     

降水背景值与酸雨定义研究

选择太平洋、印度洋、大西洋、北冰洋、内陆丽江玉龙雪山山麓背景降水Ｈ＋、Ｃａ２＋、Ｍｇ２＋、ＳＯ２－４、ＮＯ－３等降水化学组分的背景统计值，研究组分与Ｈ＋的相关性，从而提出定义海洋降水ｐＨ４８、内陆５０为酸雨，以及背景值是一个区间值的理论依据     

乐山市大气中二氧化硫与硫酸盐化速率、降水硫酸盐的相关性分析

乐山市大气中二氧化硫与硫酸盐化速率、降水硫酸盐的相关性分析赵志坚（乐山市环保科研监测所６１４０００）大气中的硫化物主要是ＳＯ２、ＳＯ３、Ｈ２Ｓ、Ｈ２ＳＯ４及硫酸盐，ＳＯ存在大气中大多被氧化成硫酸雾和硫酸盐气溶胶，降水能将大气中的可溶性成分以及颗粒物清...     

黄河水中六价铬和总铬的前处理和保存方式试验研究

黄河水中六价铬和总铬的前处理和保存方式试验研究解敏丽（山东省环境监测中心站，济南２５００１３）对含泥沙等悬浮物质的黄河水样，六价铬和总铬的稳定性（１）不受容器材料ＢＧ和ＰＥ的影响，保存２８天，误差＜７％；（２）在室温。４℃冷藏或用ＮａＯＨ调ｐＨｇ一１...     

Investigation of arsenic speciation on drinking water treatment media utilizing automated sequential continuous flow extraction with IC-ICP-MS detection

Three treatment media, used for the removal of arsenic from drinking water, were sequentially extracted using 10 mM MgCl2(pH 8), 10 mM NaH2PO4(pH 7) followed by 10 mM (NH4)2C2O4(pH 3). The media were extracted using an on-line automated continuous extraction system which allowed the arsenic in each of the extraction fluids to be speciated on-line using IC-ICP-MS. The 10 mM MgCl2 preferentially extracted As(III) from each of the media. The percentage of the arsenic extracted by the MgCl2, relative to a HNO3/H2O2 digestion of the media, ranged from 0.1-2.3% for the three solids. The next sequential extraction fluid, 10 mM NaH2PO4, extracted some of the residual As(III) remaining on each of the media but the predominant species extracted was As(V). The 10 mM NaH2PO4 extracted 15.3 to 42.8% of the total arsenic relative to a total digested concentration for each of the media. The As(III) and As(V) stability studies conducted in these two extraction fluids indicated that conversion between As(III) and As(V) was not significant for the short extraction fluid sample contact time associated with the on-line continuous flow extraction cell. Finally, the 10 mM (NH4)2C2O4 extraction fluid was utilized in an off-line analysis mode because the Fe and As concentrations extracted from the media were not compatible with direct ICP-MS detection. The (NH4)2C2O4 extracted 2.9-29% As(III) for all three media and caused an oxidation of As(III) to As(V) during the extraction period for one of the three media. The sum of the arsenic from each of the three extraction fluids represented 92%, 44% and 53% of the available total arsenic for the three media, respectively. The speciation results for each media were obtained by adding all the speciation results from all three extraction fluids together and the resulting distribution of As(III)/As(V) compared well with the speciation results obtained via XANES.     

Investigation of sequential and enzymatic extraction of arsenic from drinking water distribution solids using ICP-MS

A sequential extraction approach was utilized to estimate the distribution of arsenite [As(iii)] and arsenate [As(v)] on iron oxide/hydroxide solids obtained from drinking water distribution systems. The arsenic (As) associated with these solids can be segregated into three operationally defined categories (exchangeable, amorphous and crystalline) according to the sequential extraction literature. The exchangeable As, for the six drinking water solids evaluated, was estimated using 10 mM MgCl(2) and 10 mM NaH(2)PO(4) and represented between 5-34% of the total As available from the solid. The amorphously bound As was estimated using 10 mM (NH(4))(2)C(2)O(4) and represented between 57-124% of the As available from the respective solid. Finally, the crystalline bound As was estimated using titanium citrate and this represented less than 1.5% of the As associated with the solids. A synthetic stomach/intestine extraction approach was also applied to the distribution solids. The stomach fluid was found to extract between 0.5-33.3 microg g(-1) As and 120-2,360 microg g(-1) iron (Fe). The As concentrations in the intestine fluid were between 0.02-0.04 microg g(-1) while the Fe concentration ranged from 0.06-0.7 microg g(-1) for the first six drinking water distribution solids. The elevated Fe levels associated with the stomach fluid were found to produce Fe based precipitates when the intestinal treatment was applied. Preliminary observations indicate that most of the aqueous Fe in the stomach fluid is ferric ion and the observed precipitate produced in the intestine fluid is consistent with the decreased solubility of ferric ion at the pH associated with the intestine.     

Chemical oxidation of C. I. Reactive Red 2 using Fenton-like reactions

A detailed investigation on the kinetics of the oxidative degradation of a reactive dye, C. I. Reactive Red 2 by hydroxyl radicals generated by H202 and Fe2+ has been carried out in aqueous acidic media. Effects of different parameters like initial concentration of dye, H2O2, Fe2+, pH of the solution, reaction temperature and added electrolytes on the oxidation process have been studied. The results indicate that 1.63 x 10(-4) mol dm(-3) dye can be most effectively degraded at a dye: Fe2+: H2O2 molar ratio of 1:0.22: 8.13 at pH approximately 2.7 and at 299 K. The addition of excess 2-propanol or t-butyl alcohol, well known scavengers of hydroxyl radicals, almost stopped the degradation of the dye indicating the absence of any possible reductive pathways in the degradation. The results may be useful for designing the treatment systems of wastewater containing various reactive dyes.     

水和废水中总氮的现场快速分析方法研究

在现行水中总氮分析方法的基础上，利用便携式分光光度计和密封消解管，实验了过硫酸钾氧化、硫酸联氨还原、重氮－偶联反应的最佳条件，讨论了碱性过硫酸钾溶液用量及硫酸联氨溶液用量对分析结果的影响，从而建立了水体总氮的碱性过硫酸盐消解－分光光度分析方法，该方法可在现场简便快速地测定水和废水中的总氮。     

Metal immobilization and phosphorus leaching after stabilization of pyrite ash contaminated soil by phosphate amendments

In this study we would like to show the importance of a holistic approach to evaluation of chemical stabilization using phosphate amendments. An extensive evaluation of metal stabilization in contaminated soil and an evaluation of the leaching of phosphorus induced after treatment were performed. The soil was highly contaminated with Cu (2894 mg kg(-1)), Zn (3884 mg kg(-1)), As (247 mg kg(-1)), Cd (12.6 mg kg(-1)) and Pb (3154 mg kg(-1)). To immobilize the metals, mixtures of soil with phosphate (from H(3)PO(4) and hydroxyapatite (HA) with varying ratios) were prepared with a constant Pb : P molar ratio of 1: 10. The acetic acid extractable concentration of Pb in the mixture with the highest amount of added phosphoric acid (n(H(3)PO(4)) : n(HA) = 3 : 1) was reduced to 1.9% (0.62 mg L(-1)) of the extractable Pb concentration in the untreated soil, but the content of water extractable phosphorus in the samples increased from 0.04 mg L(-1) in the untreated soil sample up to 14.3 mg L(-1) in the same n(H(3)PO(4)) : n(HA) = 3 : 1 mixture. The high increase in arsenic mobility was also observed after phosphate addition. The PBET test showed phosphate induced reduction in Pb bioavailability. In attempting to stabilize Pb in the soil with the minimum treatment-induced leaching of phosphorus, it was found that a mixture of soil with phosphate addition in the molar ratio of H(3)PO(4) : HA of 0.75 : 1 showed the most promising results, with an acetic acid extractable Pb concentration of 1.35 mg L(-1) and a water extractable phosphorus concentration of 1.76 mg L(-1). The time-dependent leaching characteristics of metals and phosphorus for this mixture were evaluated by a column experiment, where irrigation of the soil mixture with the average annual amount of precipitation in Slovenia (1000 mm) was simulated. The phosphorus concentration in the leachates decreased from 2.60 mg L(-1) at the beginning of irrigation to 1.00 mg L(-1) at the end.     

从湿冶钒渣中回收V2O5的试验研究

通过对钒渣经碱浸和酸浸后V2O5回收率的比较，确定了应用H2SO4－氟化物浸出工艺可使渣中钒大部分转变为可溶性盐。分别采用H2SO4－NH4HF2及H2SO4－CaF2浸出工艺从湿冶钒渣中提取V2O5，前者较为满意，V2O5浸出率在65％以上，且氟化物可循环利用。     

Atmospheric aerosol concentration level and chemical characteristics of water-soluble ionic species in wintertime in Beijing,China

Total suspended particulate (TSP) samples were collected during wintertime from November 24, 1998 to February 12, 1999 in Beijing. Ionic species including Cl-, NO3(-), SO4(2-), Na+, NH4(+), K+, Mg2+ and Ca2+ were determined by Ion Chromatography (IC). The sum average concentration of all the determined ions accounted for 18.9% of the TSP concentration, and SO4(2-) appeared the dominant ion with an average concentration of 30.84 microg m(-3); the sum mass concentration of SO4(2-), NO3(-), Ca2+ and NH4(+) accounted for about 83.2% of all the eight ions measured. The study indicated that the chemical form of sulfate and ammonium varies with TSP concentration levels. During heavy pollution periods, the average TSP concentration was 0.66 mg m(-3), and the NH4(+)/SO4(2-) molar ratio was low (0.58). It indicated that sulfate may present as CaSO4 and (NH4)2SO4 x CaSO4 x 2H2O. When TSP concentration (average 0.186 mg m(-3)) was relatively low, the NH4(+)/SO4(2-) molar ratio was 1.94, close to the theoretical ratio of 2 of (NH4)2SO4. Under this condition (NH4)2SO4 is expected to exist as the major form of sulfate. When the TSP concentration level was medium (average 0.35 mg m(-3)), the NH4+/SO4(2-) molar ratio appeared an average value (1.27), (NH4)2SO4, (NH4)2SO4 x CaSO4 x 2H2O and CaSO4 are expected to be present in those aerosol particles. Meteorological conditions including wind speed and wind direction were related to the TSP concentration level.     

Speciation and preservation of inorganic arsenic in drinking water sources using EDTA with IC separation and ICP-MS detection

The native distribution of As(III) and As(v) in drinking water supplies can influence the treatment removal strategy. The stability of As(III) and As(v) in iron-rich drinking waters can be affected by the formation of Fe precipitates (Fe oxides and/or hydroxides designated by "FeOOH"). These precipitates (ppts) can form during the transport of the sample to the laboratory for arsenic speciation analysis. The analysis of the ppt indicates considerable loss of the aqueous arsenic species (As(aq)) to the solid phase "FeOOH" ppt. Studies of laboratory reagent water containing both As(III) and Fe(III) indicate that the resulting "FeOOH" ppt contained a mixture of As(III) and As(v) with near quantitative removal of the As(aq) in 18 hr. The corresponding aqueous fraction after filtration through a 0.45 microm filter was composed primarily of As(v). The formation of "FeOOH" ppt and the loss of As(aq) to the ppt can be virtually eliminated by the use of EDTA, which sequesters the FeIII). Reagent water fortified with Fe(III), As(III) and EDTA produced less than a 1 ppb change in the As(III)aq concentration over 16 d. The EDTA treatment was also tested on three well waters with different native As(III )/As(v) ratios. The native distribution of As(III)/As(v) was stabilized over a period of 10 d with a worst case conversion of As(III) to As(v) of 2 ppb over a 30 d period. All well waters not treated with EDTA had dramatic losses (a factor of 2-5) of As(aq) in less than 1 d. These results indicated that EDTA preservation treatment can be used to preserve As(aq) in waters where the predominant species is the reduced form [As(III)] or in waters which the predominant species is the oxidized form [As(v)]. This preliminary investigation of EDTA to preserve As species in Fe-rich waters indicates stability can be achieved for greater than 14 d.     

Adsorption and removal of oxo-anions of arsenic and selenium on the zirconium(IV) loaded polymer resin functionalized with diethylenetriamine-N,N,N',N'-polyacetic acid

A polymer adsorbent in which a Zr(IV)-edta complex analogue is immobilized has been prepared and applied to the removal of oxo-anions of As(III), As(V) and Se(IV). Effective retention of these anions has been demonstrated with the proposed polymer complex system. The adsorption mechanism of oxo-anions onto the Zr(IV)-chelated polymer complex has been investigated using Zr(IV)-edta as the model compound. The formation of mixed complexes with oxo-anions has been exemplified by the isolation of the carbonato complex K2[Zr(CO3)edta].3H2O, the structure of which has been confirmed by X-ray crystallography. NMR study suggests that oxo-anions that form weak or moderate conjugate acids, including those of As(III), As(V) and Se(IV), can form mixed complexes with Zr(IV)-edta using the unsaturated coordination site. However, oxo-anions of strong conjugate acids did not show any appreciable interaction with this complex. According to these observations, retention of oxo-anions on the Zr(IV)-chelated polymer complex has been interpreted by a ligand substitution reaction. The adsorption characteristics of As(III), As(V) and Se(IV) on the Zr(IV)-loaded resin have been examined with respect to the equilibrium adsorption, percentage extraction and the effect of co-existing ions. The adsorption and desorption cycles of the oxo-anions have been demonstrated using a column packed with the proposed resin without any loss of column performance, which indicates the possibility for repeated use.     

Near-real-time determination of hydrogen peroxide generated from cigarette smoke

The ability to monitor hydrogen peroxide (H2O2) in aqueous smoke extracts will advance our understanding of the relationship between cigarette smoke-induced oxidative stress, inflammation, and disease and help elucidate the pathways by which the various smoke constituents exert their pathogenic effects. We have demonstrated, for the first time, the measurement of H2O2 production from cigarette smoke without prior separation of the sample. Cigarettes were tested on a commercial smoking machine, such that the whole smoke or gas vapor phase was bubbled through phosphate buffered saline solution at pH 7.4. Aliquots of these solutions were analyzed using an Amplex Red/horseradish peroxidase fluorimetric assay that required only a 2 minute incubation time, facilitating the rapid, facile collection of data. Catalase was used to demonstrate the selectivity and specificity of the assay for H2O2 in the complex smoke matrix. We measured approximately 7-8 microM H2O2 from two reference cigarettes (i.e., 1R4F and 2R4F). We also observed 9x more H2O2 from whole smoke bubbled samples compared to the gas vapor phase, indicating that the major constituent(s) responsible for H2O2 formation reside in the particulate phase of cigarette smoke. Aqueous solutions of hydroquinone and catechol, both of which are particulate phase constituents of cigarette smoke, generated no H2O2 even though they are free radical precursors involved in the production of reactive oxygen species in the smoke matrix.