离子色谱法测定降水中的阳离子

应用Waters新型阳离子分离柱快速，准确地一次性同时测定降水中阳离子（Na^ ,NH4^ ,K^ ,Mg^2 ,Ca^2 )，该方法具有良好的精密度、线性相关系数和加标回收率。     

A study on hexachromic ion selective electrode based on supported liquid membranes

An ion selective electrode (ISE) for determining Cr(VI) using supported liquid membranes (SLMs) containing trioctylphosphine oxide (TOPO) was investigated in this study. TOPO, as a carrier, had a high selectivity for Cr(VI) against interfering ions such as sulfate, nitrate, nitrite, and chloride. The composition of the SLM was optimized as 0.193 g TOPO/1 mL NPOE (o-nitrophenyl octyl ether)/0.5 g poly (vinyl chloride) for detection of Cr(VI). The Cr(VI) concentration was measured in the range of1 × 10^-3 to 1 × 10^-6 M with the SLM prepared in the study. It seemed that Cr(VI) was transported in the SLM as a triply charged ion indicated by the slope of the emf response. Selectivity coefficients and detection limits of Cr(VI) in the presence of interfering ions were determined experimentally using the fixed interference method.     

Monitoring of Fogwater Chemistry in the Gulf Coast Urban Industrial Corridor: Baton Rouge (Louisiana)

Seventeen fog events were sampled in Baton Rouge, Louisiana during 2002–2004 as part of characterizing wet deposition by fogwater in the heavily industrialized corridor along the Louisiana Gulf Coast in the United States. These samples were analyzed for chemical characteristics such as pH, conductivity, total organic and inorganic carbon, total metals and the principal ion concentrations. The dominant ionic species in all samples were NH₄⁺, NO₃⁻, Cl⁻ and SO₄²⁻. The pH of the fogwater sampled had a mean value of 6.7 with two cases of acidic pH of 4.7. Rainwater and fogwater pH were similar in this region. The acidity of fogwater was a result of NO₃⁻ but partly offset by high NH₄⁺. The measured gaseous SO₂ accounted for a small percentage of the observed sulfate concentration, indicating additional gas-to-particle conversion of SO₂ to sulfate in fogwater. The gaseous NO_x accounted for most of the dissolved nitrate and nitrite concentration in fogwater. The high chloride concentration was attributable to the degradation of chlorinated organics in the atmosphere. The metal composition was traced directly to soil-derived aerosol precursors in the air. The major metals observed in fogwater were Na, K, Ca, Fe, Al, Mg and Zn. Of these Na, K, Ca and Mg were predominant with mean concentrations > 100 μM. Al, Fe and Zn were present in the samples, at mean concentrations < 100 μM. Small concentrations of Mn (7.8 μM), Cu (2 μM), Pb (0.07 μM) and As (0.32 μM) were also observed in the fogwaters, and these were shown to result from particulates (PM_2.5) in the atmosphere. The contribution to both ions and metals from the marine sources in the Louisiana Gulf Coast was minimal. The concentrations of all principal ionic species and metals in fogwater were 1–2 orders of magnitude larger than in rainwater. Several linear alkane organic compounds were observed in the fogwater, representing the contributions from petroleum products at concentrations far exceeding their aqueous solubility. A pesticide (atrazine) was also observed in fogwater, representing the contribution from the agricultural activities nearby.     

水中阴离子表面活性洗涤剂测定新方法的研究

介绍了水中阴离子表面活性剂测定新方法，该法与亚甲蓝法比较，具有操作步骤简单，萃取剂用量少的优点。     

1-(2,6-二氯-4-硝基苯)-3-(4-硝基苯)-三氮烯光度法测定矿山废水中的锌

研究了用1-(2,6-二氯-4-硝基苯)-3-(4-硝基苯)-三氮烯(DCNPNPT)分光光度法快速直接测定锌的方法。在表面活性剂TritonX-15的存在下,pH=9.5～10.5的Na2B4O7-NaOH介质中,DCNPNPT与锌( )可生成1∶3的橙黄色络合物。最大吸收波长为445nm,同时在535nm配合物有一最大负吸收,建立以535nm为参比波长,445nm为测定波长的双峰双波长法进行测定,表观摩尔吸光系数可达1.12×105L/(mol·cm)。用拟定的方法测定矿山废水中的锌,与原子吸收法测定的结果十分吻合,结果令人满意。     

乌鲁木齐市降水酸度及化学特征的初步研究

降水酸度和离子平衡研究结果表明,乌鲁木齐市降水为非酸性雨,但其PH值有较明显的季节变化,降水中的SO_4~(2-)、Ca~(2+)、和NH_4~+是影响酸度的关键离子,与其他地区相比,乌鲁木齐市降水中的Ca~(2+)浓度是酸雨区(贵阳、重庆)平均值的3.50倍,是非酸雨区(北京、天津)平均值的1.86倍。可见,乌鲁木齐市降水酸度的高低,不仅取决于酸性离子浓度,而且更重要的是取决于碱性离子浓度。     

Seasonal Variation of Chemical Composition in Fine Particles at Gosan, Korea

PM_2.5 aerosol samples were collected at Gosan in Jeju Island during six intensive measurement periods between November 2001 and August 2003. In order to investigate the chemical composition of fine particles, major ion components, trace elements, and elemental and organic carbon were analyzed. Quite different seasonal characteristic in the chemical composition of fine particles was observed. The concentration of most secondary aerosol components showed a summer minimum and a winter maximum with higher correlation between them at Gosan. This fact clearly reveals the possibility of long-range transport of such pollutants in winter. On the other hand, OC and EC had the highest concentration and good correlation with ion components, such as K⁺, Ca²⁺ in fall. It means that biomass burning could significantly influence the ambient fine carbonaceous particulate in fall, which was primarily long-range transported.     

水中阴离子洗涤剂测定方法的改进

根据实际工作经验，本文对标准曲线绘制方法和有机溶剂用量进行了减半改进，优化了显色剂的用量及萃取分析条件，其相对误差在0．5％以内，加标回收率在97．8％-98．5％之间，精密度和准确度均达到了要求，和标准方法相比测定结果无显著差异。     

化学气相沉积法对13X分子筛孔径修饰及吸附性能研究

化学气相沉积法可对１３Ｘ分子筛进行孔径修饰，并用于含重金属离子废水的净化处理。研究结果表明，随１３Ｘ分子筛外表面ＳｉＯ２沉积量的增加，孔径收缩。     

过氧化氢加Fe~(3+)作催化剂处理含酚废水的研究

采用H_2O_2/Fe~(3+)对合酚废水进行了催化氧化的研究。对于溶液pH值、过氧化氢浓度、铁离子浓度与酚、COD、TOC去除的关系作了探讨。结果表明,在酸性pH值范围内,Fe~(3+)作催化剂可获得不低于Fe~(2+)作催化剂时的催化活性,对酚、COD和TOC都有较好的去除率。而在初始pH=7时,Fe~(3+)作催化剂的反应活性明显降低。自动连续控制溶液pH=7.0±0.2时,无论是高铁或低铁离子都大幅度降低其反应活性。同时也证实,低浓度铁离子不论是Fe~(3+)或Fe~(2+)也都降低其催化反应活性。