分光光度法测定染色废水的色度

为消除测定染色废水色度的主观误差，采用分光光度法测定染色废水的色度，与稀释倍数法相比，具有精确，重现性好，适用范围广等特点，ＰＨ值对色度的测定有明显影响，控制ＰＨ值为７．６０，测定色度具有可比性。     

便携式XRF在污染地块土壤金属元素调查中的应用

研究了便携式X荧光光谱仪（PXRF）测定土壤中砷、铅、铬、铜、锌和镍的性能，评估其检出限、精密度和准确度，探索了土壤水分和粒径对测定结果的影响程度，并与常规实验室分析方法测定结果进行比对。结果表明，PXRF测定土壤中砷、铅、铬、铜、锌和镍的检出限为5~15mg/kg，标准物质测定结果的相对标准偏差（RSD）≤8.6%，相对误差在±15%以内。随着土壤水分含量的增加，各金属元素测定结果均呈下降趋势，而RSD有上升趋势。土壤粒径对测定结果的影响较小，随着土壤粒径减少，各金属元素测定结果的RSD略有下降趋势。PXRF可以简单、快速地测定多种重金属元素，适用于污染地块重金属元素的现场实时监测。     

测定总铬应注意的问题

测定总铬应注意的问题刘超英（山东省荷泽地区环境监测站，荷泽２７４０１０）水样中的三价铬氧化为六价铬，其溶液呈很强的酸性。若在消化过程结束后，为提高测定结果的精密度将溶液调至中性，会直接影响水样测定结果的准确度，使测定值偏低。实验表明，水样消化完毕，溶...     

干扰曲线扣除法测定废水中苯胺类和硝基苯类

使用比色法测定苯胺和硝基苯时，苯胺会严重影响硝基苯的测定。采用干扰曲线扣除法可以定量描述苯胺对硝基苯的影响，得到水样中硝基苯的真实含量。用这种方法测定苯胺，标准差为0.29μg，相对标准差为1.9％，回收率为97％；测定硝基苯，标准差为0.57μg，相对标准差为5.6％，回收率为95％。     

固体废物氰化物总量和浸出毒性测定方法的比较

中国现行的固体废物氰化物总量和氰化物浸出毒性的分析方法存在缺陷，不便于广泛指导监测工作，笔者优化了固体废物氰化物测定的前处理方法，明确了固体废物氰化物总量、氰化物浸出毒性测定时的样品粒径、浸提方法和消解方法，建立了容量法、分光光度法、流动注射法测定固体废物氰化物总量和浸出毒性的方法，并与标准方法（离子色谱法）进行比较。实验结果表明：容量法、分光光度法、流动注射法测定结果与离子色谱法无显著差异，3种方法测定固体废物氰化物总量加标回收率为80.5%~102%，平行样测定相对标准偏差为3.0%~6.9%，3种方法测定固体废物氰化物浸出毒性加标回收率为80.1%~107%，平行样测定相对标准偏差为7.8%~9.5%，3种方法测定结果精密度和准确度良好，均能够满足固体废物氰化物总量和氰化物浸出毒性的测定要求。其中容量法、分光光度法由于其仪器设备简单、操作简便，可用于突发环境事件应急监测等情况下固体废物氰化物的测定。但容量法检出限较高，不能满足评价标准较低的分析测试工作要求，离子色谱法、分光光度法和流动注射法检出限均能满足一般分析测试要求。     

气相色谱法测定水样中元素磷

本文研究了用气相色谱法测定水样中元素磷。该方法灵敏度高，再现性好，简便快速，水中各种污染物不干扰测定。本方法的检出浓度为０．２５μｇ／Ｌ，适用于测定生产黄磷的行业排放的废水以及测定受元素磷污染的水体。     

5B型COD快速测定仪在监测工作中的应用

COD快速测定仪在环境监测工作中已逐步使用，为了验证快速测定仪和重铬酸钾法在COD测定中是否具有等效性，我们采用两种方法同时对标准样品以及不同种类的废水进行测定，对测定结果进行了F检验和T检验，同时做了回率测定，并对快速测定仪的精密度和抗氧离子的干扰进行了测定。     

双硫腙比色法测定锌实验条件的改进

双硫腙比色法测定锌实验条件的改进祁成华，郑新秀，严香文（新疆昌吉州环境监测站８３１１００）双硫腙比色法测定锌适用于测定天然水和轻度污染的地表水，但该法易受实验室环境的干扰，空白试验值高．曲线的相关性较差。通过对实验条件的改进．大幅度降低空白测定值，提...     

废不化学需氧量测定中稀释倍数的确定

根据化学需氧量测定原理和分析方法，推导出化学需氧量测定限，由测定确定不同浓度废水化学需氧量测定的稀释倍数。     

停流──诱导动力学光度法测定微量钒

Ｃｒ（Ⅳ）－Ⅰ－淀粉体系的氧化还原反应可被Ｃｒ（Ⅳ）－Ｖ（Ⅳ）反应所诱导，本文据此提出了一种测定微量钒（Ⅳ）的停流－诱导动力学光度法，并建立了测定最佳条件。常见离子中，除Ｆｅ２＋，Ｔｒ１＋，Ｓｅ４＋，Ａｓ３＋以外，大部分不干扰测定。本法测定钒（Ⅳ）的线性范围为０～１．８μｇ／ｍｌ；测定了土壤中微量钒，六次测定的ＲＳＤ＝２．４５％。     

超声辅助离子液体-分散液液微萃取-高效液相色谱法测定水中苯胺类化合物

本研究建立了超声辅助离子液体-分散液液微萃取-高效液相色谱测定环境水样中苯胺(AN)、对氟苯胺(4-FA)、对硝基苯胺(4-NA)、对氯苯胺(4-CA)四种苯胺化合物的方法。以最常用的烷基咪唑六氟磷酸盐类离子液体为萃取剂,通过超声加速萃取剂的分散程度,提高了萃取效率。该方法的检测限达到0.1~73 ng/ml,对黄河水和自来水中的加标回收率均在90.5%~113%之间,回收效果良好。与传统的液液萃取相比,该萃取方法具有绿色、快速、富集效果好、有机溶剂消耗小的优点,可以满足环境水体中苯胺类化合物的测定。     

金属离子和氧化剂对3,5-二氯酚光化学降解的影响

在实验条件下 ,Fe2 +、KCl O3、KCl O4 、KBr O3、KIO4 对 3 ,5 -二氯酚光化学降解起加速作用 ,且随其浓度增大 ,加速作用也在增强。KIO4 的加速作用比较强。光照时 ,KIO4 +Mn2 +对 3 ,5 -二氯酚光化学降解的加速作用非常显著。无光照时 ,当 KMn O4 浓度增加时 ,3 ,5 -二氯酚被迅速氧化 ;KIO4 +Mn2 + /Fe2 + 能够使 3 ,5 -二氯酚发生化学降解 ,尤其是 KIO4 +Mn2 + 的作用。     

土壤和底泥中砷、铬、锰测定的前处理技术

试验了土壤和底泥中砷的前处理技术，其目的是能对土壤、底泥中砷、铬、锰在一次前处理中制备成试液，比色法分析。试验表明，用Ｈ２ＳＯ４－Ｈ３ＰＯ４－Ｈ２Ｏ２进行前处理是可行的。方法简单、挥发酸雾少，用标准参考物质检验证明，分解完全，数据准确，有粒较好一致性。     

Methane fluxes in aerobic soils

Aerobic soils are an important sink for methane (CH₄), contributing up to 15% of global CH₄ destruction. However, the sink strength is significantly affected by land management, nitrogen (N) fertilizers and acidity. The rates of uptake from the atmosphere of both enhanced (10 ppmv) and ambient (2 ppmv) concentrations of CH₄ were measured in laboratory incubations of soil cores under controlled conditions taken from sites in the U.K. and Germany. The most rapid rates of uptake were measured in soil from deciduous woodland at pH 4 (measured in water). Extended (150 years) cultivation of land for arable crops reduced uptake rate by 85% compared to that in the same soil under an adjacent woodland. The long-term application of ammonium (NH₄)-based fertilizer, but not nitrate (NO₃)-based fertilizer, completely inhibited CH₄ uptake, but the application for the same period of farmyard manure (FYM) that contained more N than the fertilizer had no inhibitory effect. Where a combination of FYM and inorganic fertilizer was applied there was a reduction in methane uptake rate compared to plots receiving solely FYM.Autoclaving showed that the uptake of CH₄ was microbially mediated. The most likely causes of the inhibitory effects seen are (i) insufficient concentrations of CH₄ in situ to activate methane monooxygenase; (ii) the direct inhibition of CH₄ oxidation by NH _inf4 ^sup+ ions; (iii) the suppression of methanotrophs by NH₄-based fertilizers; (iv) the requirement of methanotrophs for a stable soil architecture which is incompatible with the disturbance caused by regular arable cultivation.     

垃圾渗出液中酚类物质的气相色谱分析

建立了一种用气相色谱法准确、快速测定垃圾渗出液中酚类物质的新方法。外标法定量分析 4 -甲基苯酚及苯酚。采用填装了 80～ 1 0 0目 Chromosorb WAW DCMS的玻璃填充柱 ,担体上涂渍了 2 % OV-1 7,2 .5% QF-1的固定液 ,分离酚类物质效果较好 ,线性范围为 1 0 0～ 1 50 0 mg/ L,相关系数为 0 .9996,方法回收率为 94 .7%。     

Precipitation Chemistry and Occurrence of Acid Rain Over Dhanbad, Coal City of India

The present study investigated the chemical composition of wet atmospheric precipitation over Dhanbad, coal city of India. The precipitation samples were collected on event basis for three years (July 2003 to October 2005) at Central Mining Research Institute. The precipitation samples were analyzed for pH, conductivity, major anions (F, Cl, NO₃, SO₄) and cations (Ca, Mg, Na, K, NH₄). The pH value varied from 4.01 to 6.92 (avg. 5.37) indicating acidic to alkaline nature of rainwater. The pH of the rainwater was found well above the reference pH (5.6), showing alkalinity during the non-monsoon and early phase of monsoon, but during the late phase of monsoon, pH tendency was towards acidity (<5.6~pH) indicating the non-availability of proper neutralizer for acidic ions. The observed acidic events at this site were 91, (n = 162) accounting 56% for the entire monitoring months. The (NO₃ + Cl)/SO₄ ratio in majority of samples was found below 1.0, indicating that the acidity is greatly influenced by SO₄. The calculated ratio of (Ca + NH₄)/(NO₃ + SO₄) ranges between 0.42–5.13 (average 1.14), however in most of the samples, the ratio is greater than unity (>1.0) indicating that Ca and NH₄ play an important role in neutralization of acidic ions in rainwater. Ca and SO₄ dominate the bulk ionic deposition and these two ions along with NH₄ accounts 63% of the annual ionic deposition.     

高锰酸钾─硫酸─过硫酸钾消化冷原子荧光法测定总悬浮颗粒物中痕量汞

测定环境大气悬浮颗粒物中痕量汞，用４种消化液进行对比实验，其中高锰酸钾─硫酸─过硫酸钾混合液消化效果较好，用冷原子荧光测定操作简便，检测下限为０．０５μｇ／Ｌ，重复测定９个实际样品，相对标准偏差为１１．６％，变异系数为１０．４％，添加汞标准回收率为１０２％。     

Water quality test based on dielectrophoretic measurements of fresh water algae Selenastrum capricornutum

A method is described whereby dielectrophoresis of algal cells is used to perform rapid water quality analysis, specifically detecting the presence of CuSO4. The dielectric collection spectrum of the fresh water alga Selenastrum capricornutum was determined for a range of concentrations of CuSO4 from 25 mg L(-1) to 0.25 mg L(-1) for exposure times of 15 min and 18 h. In all cases increasing the concentration of CuSO4 reduced cell collection, but a step reduction was observed in collection between 2 mg L(-1) and 5 mg L(-1). This method has potential for forming a rapid, low-cost test for water quality with broad specificity and significantly reduced analysis time compared to current methods.     

Diurnal variation of methane emissions from an alpine wetland on the eastern edge of Qinghai-Tibetan Plateau

Alpine wetland is a source for CH₄, but little is known about methane emission from such wetland, especially about its diurnal pattern. In this study we tried to probe the diurnal variation in methane emission from alpine wetland vegetation. The average methane emission rate was 9.6 ± 3.4 mg CH₄ m^???2 h^???1. There was an apparent diurnal variation pattern in methane emission with one minor peak at 06:00 and a major one at 15:00. The sunrise peak was consistent with a two-way transport mechanism for plants (convective at daytime and diffusive at night-time). CH₄ emission was found significantly correlated with redox potentials. The afternoon peak could not be explained by diurnal variation in soil temperature, but could be attributable to changes in CH₄ oxidation and production driven by plant gas transport mechanism. The results have important implications for sampling and scaling strategies for estimating methane emission from alpine wetlands.     

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.