高压蒸汽消解法测定土壤、底质中的有机质

用“自控式高压蒸汽消解器”作加热器,将测定土壤、底质中有机质由敞口油浴法转变为密封高压蒸汽消解法,用实际土样全面优化了温度、硫酸浓度、时间等消解条件,建立了高压蒸汽消解法测定土壤、底质中有机质的方法,并用于不同地方、不同类型土壤和底质中有机质测定,同时用油浴法作对照,相对误差在－３７～５３％之间。该方法精密度好,无实验室二次污染,批处理样品数量多,可作为测定土壤、底质中有机质的常规方法。     

纵向塞曼恒温平台石墨炉原子吸收法测定土壤,底质中镉和砷

为准确测定土壤中低含量元素镉和砷,研究了集恒温平台石墨炉（ＳＴＰＦ）一体的纵向塞曼效应背景校正,最大功率升温,钯作基体改进剂和吸收峰面积积分的最新分析方法。方法测定结果,镉和砷的检测限（３σ）分别为３５×１０－１３ｇ和５４×１０－１１ｇ;相对标准差（ｎ＝６）分别为４１％～５２％和２６％～４５％;回收率分别为８６５％～１０９％和９１２％～１０５％     

程序控温石墨消解-原子荧光法测定土壤中总砷

采用程序控温石墨全自动消解仪消解土壤样品，原子荧光光谱法测定总砷。通过试验确定原子荧光光度计的最佳工作条件，使得该方法在2.00μg／L ～20.0μg／L 范围内线性良好，检出限为0.025 mg／kg，加标回收率在96.0％～10^5％之间，RSD为1.9％～3.3％。用该方法与国标法同时测定土壤标准样品和实际样品，结果无显著差异。     

气相色谱法测定废水和废气中N′,N-二甲基甲酰胺

以气相色谱石英毛细管柱分离、ＦＩＤ检测,测定废水和废气中Ｎ′,Ｎ－二甲基甲酰胺（ＤＭＦ）。在１０ｍｇ／Ｌ～１８８１０ｍｇ／Ｌ范围内有良好的线性关系。检测限：废水为０５ｍｇ／Ｌ;废气为０８ｍｇ／ｍ３。样品测定的相对标准差为４％～８％,回收率在７６％～１１２％之间,精密度和准确度均较好     

气相色谱法测定空气中丙烯酸酯

讨论了用气相色谱仪测定被污染空气中丙烯酸甲酯、丙烯酸乙酯、甲基丙烯酸甲酯、丙烯酸丁酯的方法条件。方法检出下限在６ｎｇ范围,相对标准偏差为１４～６９％,回收率为９０６～１１０５％。实验还显示丙烯酸酯污染空气问题不容忽视。     

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％。     

吸光光度法测定工业污水中NH_4~ —N含量

本法根据ＮＨ＋４与水杨酸在次氯酸钠和亚硝基铁氰化钠的作用下形成一种有色配合物的反应,最大吸收波长为７００ｎｍ,体系中ＮＨ＋４－Ｎ浓度在０～１４μｇ／ｍｌ范围内符合朗伯—比耳定律,测得摩尔吸光系数ε＝１１×１０４。本法灵敏、准确、重现性好,测试误差小于３％,回收率为９６～１０２３１％。     

氧化偶氮胂M褪色光度法测定微量锰的研究

在酸性介质中,Ｍｎ（Ⅶ）强的氧化性对偶氮胂Ｍ有褪色作用,借此进行吸光光度法测定微量锰的研究。实验表明,在１８～２７ｍｏｌ／ＬＨ２ＳＯ４介质中,有色溶液的最大吸收波长为５４０ｎｍ,表观摩尔吸光系数为１８３×１０４Ｌ／ｍｏｌ·ｃｍ,锰量在０～１４μｇ／ｍｌ范围内与有色溶液吸光度的减少值呈线性关系。方法简单快速、选择性好、准确度高,灵敏度是高锰酸盐法的近８倍,可用于测定水样、地质样品中的微量锰。在测定某些地质样品中的微量锰时,结果满意。     

总磷测定中样品消解加热时间的改进

在《水和废水监测分析方法（第３版）》（以下简称《方法》）中,地面水总磷测定一般可采用过硫酸钾消解法消解。《方法》规定,在高压蒸汽消毒器内加热,在锅内压力达到１１ｋｇ／ｃｍ２（相应温度为１２０℃）时,要保持此压力３０ｍｉｎ。此法消解时间较长,对大批样...     

微波消解—火焰原子吸收光度法测定底质中的Cr

提出了用微波消解，火焰原子吸收法测定底质中的Cr，探讨了不同仪器条件下，不同干扰剂对样品测试的影响，用此法对样品回收测定，回收率在95．2％－102．0％之间，相对标准差1．2％－5．8％,检测限0．036mg/L。     

凯氏法测定土壤全氮的方法改进

采用凯氏法测定土壤全氮对9种不同类型的土壤进行测定,通过实验比较不同的还原剂、氧化剂和催化剂,发现以五水合硫代硫酸钠做还原剂,以硫酸为主要氧化剂,以K2SO4＋CuSO4＋TiO2做催化剂,具有操作简便、省时、无污染的优点。该方法加标回收率82.5%～96.0%,标样测试相对误差1.4%,精密度1.9%～10.8%,检出限14mg/kg。     

Comparison of USEPA digestion methods to heavy metals in soil samples

The use of appropriate analytical methods is of paramount importance for risk assessment and monitoring of potentially toxic metals in soils. In this sense, the objective of this study was to compare the effectiveness of two sample digestion methods, recommended by the Brazilian legislation for the management of contaminated areas (CONAMA 2009), aiming at the determination of environmentally available metal concentrations (USEPA 3050B, USEPA 3051A), as well as a total digestion method (USEPA 3052). Samples from 10 classes of soils were analyzed for Cu, Zn, Cd, Pb, Ni, and Hg. The results showed that the USEPA method 3051A is more efficient than the USEPA method 3050B in the extraction of levels considered environmentally available of Zn, Cu, Cd, Pb, and Ni. Besides providing a higher recovery of these elements, the method requires shorter digestion time, lower consumption of acids, and reduced risk of contamination. The USEPA method 3051A showed greater efficiency in Hg extraction in soils with higher clay content. Therefore, it is suitable for situations where a wide range of soils with different mineralogical characteristics are analyzed or in order to decrease the losses due to volatilization of the element in open systems.     

Fractionation of Aluminum in Soil and Relation to Its Concentration in Fruits

Aluminum concentrations in the fruit samples taken from different regions were determined by atomic absorption spectrometry after dry ashing digestion. To identify the aluminum phases being most responsible for fruit-available aluminum, the soil samples near the fruit plants were also analyzed for aluminum by using various digestion and selective extraction reagents. The relation between the aluminum concentrations in fruits and in soil extracts was studied. The obtained aluminum concentrations in the fruits were in the range of 1.5 to 42.0 mg kg^-1 on dry weight basis. It was observed that the aluminum concentrations of morello cherry(R² = 0.79) and mulberry (R² = 0.99) were correlated to the aluminum concentrations in citric acid extracts of the soils. While the aluminum concentrations of the EDTA and acetic acid extracts in some soils samples include 35% and 25% of total aluminum, respectively, the other soils contain only 1–2%.     

用三氯化铁定量测定苯酚的探索与应用

探索用三氯化铁作显色剂定量测定苯酚,测定波长５８０ｎｍ,线性范围１００×１０－３～１００×１０－２ｍｏｌ／Ｌ,相对误差小于±１％,与紫外吸光光度法的测定结果吻合     

消解仪－麝香草酚分光光度法测定水中总氮

采用消解仪替代高压蒸汽灭菌器消解水样,用麝香草酚分光光度法替代紫外分光光度法测定总氮.试验表明,方法在0mg/L～10.0mg/L范围内线性良好,相关系数R为0.9999;方法检出限为0.04mg/L;测定低、中、高质量浓度的标准溶液,RSD为1.1% ～5.5%;对3份实际水样进行加标回收试验,回收率为94.6% ～98.2%,测定总氮标准品,结果在保证值范围内;用该方法与国标方法同时测定水样,测定结果的相对偏差〈5%.     

土壤重金属监测过程及其质量控制

重点探讨了土壤中典型重金属含量监测过程中样品制备、含水率、预处理等因素对分析结果的影响。实验结果表明,充分风干土壤的含水率在2%～3%左右,200目土壤颗粒度可满足分析精度的要求。硝酸-氢氟酸-高氯酸的多元混酸消解体系可实现对土壤重金属的充分溶解,对标准土壤样品中各元素的回收率可达84%～98%。批次内平行样品以及批次间质控样品各元素的相对标准偏差大都小于10%,符合《土壤环境监测技术规范》的要求,表明该研究建立的系统土壤重金属检测方法结果准确可靠。     

微波消解石墨炉原子吸收法测定土壤和沉积物中的铍

以氯化钯为基体改进剂，采用微波消解石墨炉原子吸收法测定土壤和沉积物中的铍，优化了微波消解条件，考察了共存元素对测定的干扰。方法在0μg／L～4．00μg／L范围内线性良好，检出限为0．01μg／g（以取样质量0．2000g、定容体积50mL计），标准样品平行测定的RSD为3．5％～6．7％，实际样品的加标回收率为84．0％-113％。     

Application of portable gas chromatography-photo ionization detector combined with headspace sampling for field analysis of benzene, toluene, ethylbenzene, and xylene in soils

A method based on headspace (HS) sampling coupling with portable gas chromatography (GC) with photo ionization detector (PID) was developed for rapid determination of benzene, toluene, ethylbenzene, and xylenes (BTEX) in soils. Optimal conditions for HS gas sampling procedure were determined, and the influence of soil organic matter on the recovery of BTEX from soil was investigated using five representative Chinese soils. The results showed that the HS-portable-GC-PID method could be effectively operated at ambient temperature, and the addition of 15 ml of saturated NaCl solution in a 40-ml sampling vial and 60 s of shaking time for sample solution were optimum for the HS gas sampling procedure. The recoveries of each BTEX in soils ranged from 87.2 to 105.1 %, with relative standard deviations varying from 5.3 to 7.8 %. Good linearity was obtained for all BTEX compounds, and the detection limits were in the 0.1 to 0.8 μg kg^?1 range. Soil organic matter was identified as one of the principal elements that affect the HS gas sampling of BTEX in soils. The HS-portable-GC-PID method was successfully applied for field determination of benzene and toluene in soils of a former chemical plant in Jilin City, northeast China. Considering its satisfactory repeatability and reproducibility and particular suitability to be operated in ambient environment, HS sampling coupling with portable GC-PID is, therefore, recommended to be a suitable screening tool for rapid on-site determination of BTEX in soils.     

M-估计在水质监测中的应用

Ｍ估计是极大似然估计的一种简称。以水质蒸馏后４氨基安替比林分光光度法测定挥发酚和纳氏试剂比色法测定氨氮为例,分别考察了Ｍ估计与传统的最小二乘法（ＬＳ）所获取的校准曲线方程。回收试验结果表明个别异常值（＜３０％）不影响Ｍ估计,而ＬＳ估计则不然,前者在水质监测中的稳健性亦得以充分证明     

水中总氮测定方法存在问题的研究及改进

碱性过硫酸钾消解紫外分光光度法测定水中总氮采用的消解器皿是玻璃比色管,易造成空白偏高、结果偏低等问题。采用双圆柱状的消解杯对水样进行消解。结果表明,消解杯消解水中总氮,线性相关系数均大于0.999,检出限为0.05 mg/L,相对标准偏差小于5%,相对误差为0.88%~1.00%;改进后的消解器皿具有较好的精密度和准确度,能够更加准确测定水中总氮的含量。