塿土中可给态镍浸提方法的研究

在前人工作的基础上,应用主成分分析、逐步回归分析和通径分析的方法,提出了(土娄)土中可给态镍的浸提方法及影响可给态镍的土壤性质.结果表明,DTPA浸提法可作为(土娄)土中可给态镍的浸提方法,铁锰氧化物结合态镍是(土娄)土可给镍的主要来源.碳酸盐结合态镍和有机质结合态镍是(土娄)土可给镍的潜在来源.它们在调控可给态镍的储量上起着重要作用.影响(土娄)土可给态镍最重要的土壤性质是pH和E_h_7.     

固相萃取-气相色谱法快速分析水中硝基苯类化合物

建立了固相萃取-气相色谱定量分析水中硝基苯类化合物的分析方法,详尽地叙述了水样预处理过程.对固相萃取,水样预处理和色谱分离条件做了试验并予以优化.采用ODS-C18固相萃取柱将样品浓缩富集后,以DB-17色谱柱(30 m×0.32 mm×0.25 μm)为分离柱,以ECD和FID检测.方法检出限在0.12～90 μg/...     

液液萃取-高效液相色谱法同时测定水中甲萘威和阿特拉津

用二氯甲烷萃取水中的甲萘威和阿特拉津,经旋转蒸发和氮吹富集浓缩后,采用高效液相色谱二极管阵列检测器在222 nm波长下测定。甲萘威和阿特拉津在0.100 mg/L～5.00 mg/L范围内线性良好,检出限分别为0.031 μg/L和0.027 μg/L,空白水样加标平均回收率为78.5%～91.7%,平行测定3次的RSD＜5%。     

GANN模型在十溴联苯醚分散液液微萃取中的应用

文章研究目的在于用遗传神经网络模型(GANN模型)快速优化水样中十溴联苯醚分散液液微萃取的萃取条件。以水样中十溴联苯醚分散液液微萃取的正交试验为训练样本,建立十溴联苯醚分散液液微萃取条件的遗传神经网络模型。比较遗传神经网络模型和BP神经网络模型的学习速度、学习精度及网络泛化能力。采用Matlab遗传算法工具箱运用遗传神经网络模型对影响萃取回收率的因素进行优化求解,获得了水样中十溴联苯醚分散液液微萃取优化后的萃取条件,并进行实验验证。文章建立的遗传神经网络模型得到的预测值与实验值平均偏差为14.41%,R2为0.8887;最佳DLLME萃取条件为10μL四氯乙烯、0.71mL丙酮、pH=5、离子强度为20%NaCl、萃取时间10min;优化后十溴联苯醚分散液液微萃取的萃取回收率和富集因子比优化前分别提高了54%和580。     

固相膜萃取-高效液相色谱法测定地下水中的多环芳烃

采用C18固相膜萃取对地下水中15种多环芳烃进行富集净化,以二氯甲烷作洗脱溶剂,高效液相色谱法,荧光检测器测定。对萃取、浓缩和色谱条件进行优化,在1．ooixg／L～40．0μg／L范围内测定标准系列溶液并绘制标准曲线,相关系数R2〉0．999;15种多环芳烃的仪器检出限为0．4ng／L～3．0ng／L;对地下水样品加标,平均回收率在75．7％～96．7％之间;标准溶液平行测定7次的RSD为3．1％～11．9％。     

ISS-2锌渣标准样品中Zn、Pb、Cd全量浸取研究及与纯水浸提比较

锌渣标准样品２００目,已经过多家实验室协作定值,通过二种方法可提取样品中的全量Ｐｂ、Ｚｎ、Ｃｄ：（１）１＋９ＨＣｌ,密封,０１２～０１４ＭＰａ,１２１℃,６０ｍｉｎ;（２）１＋９ＨＣｌ,超声波处理,６０ｍｉｎ。     

Determination of the insecticide diflubenzuron in mushrooms by kinetic method and high-performance liquid chromatographic method

In the present study, a new sensitive and simple kinetic-spectrophotometric method for the determination of the insecticide diflubenzuron [1-(4-chlorophenyl)-3-(2,6-diflubenzoil)urea] is proposed. The method is based on the inhibited effect of diflubenzuron on the oxidation of sulphanilic acid (SA) by hydrogen peroxide in phosphate buffer in presence Cu(II) ion. Diflubenzuron was determined with linear calibration graph in the interval from 0.31 to 3.1 μg mL^?1 and from 3.1 to 31.0 μg mL^?1. The optimized conditions yielded a theoretical detection limit of 0.18 μg mL^?1corresponding to 0.036 mg Kg^?1mushroom sample based on the 3S_b criterion. The RSD is 5.03–1.83 % and 2.81–0.71 % for the concentration interval of diflubenzuron 0.31–3.1 μg mL^?1and 3.1–31.0 μg mL^?1, respectively. The reaction was followed spectrophotometrically at 370 nm. The kinetic parameters of the reaction are reported, and the rate equations are suggested. The developed procedure was successfully applied to the rapid determination of diflubenzuron in spiked mushroom samples of different mushroom species. The HPLC method was used like a comparative method to verify results.     

液相色谱质谱法测定水体及土壤中的类固醇激素

建立了水体和土壤中类固醇激素的液相色谱质谱分析方法。水样采用固相萃取方法富集,土壤样经加速溶剂萃取后由固相萃取净化和富集。处理好的样品经丹磺酰衍生化后上仪器分析。结果表明,类固醇激素在水体和土壤中的检出限分别为0.01~0.6ng/L和0.01~0.19ng/g,回收率分别为77%~97%和62%~119%,RSD小于6.04%和15.5%。该方法具有较高的准确度和精密度,适用于环境水体及土壤中类固醇激素残留的分析。     

Sequential extraction of Cs and Sr from Ain Oussera soils around Es-Salam research reactor facility

Four types of undisturbed soil in Ain Oussera region around the Es-Salam reactor facility, located in the south of Algiers, Algeria, at about 200 km, were artificially contaminated for one year with stable CsCl and SrCl₂ in order to simulate an accidental release of these elements. This study was performed using sequential extraction procedure based on Shultz method and containing six fractions. The selectivity of the extraction protocol was confirmed by analyzing some elements (Ca, C, Fe, Mn, Si and Al) designed as indicators of the targeted phases. The obtained results showed an acceptable reproducibility, in view of the coefficients of variation that were in most cases less than 15%. The results revealed a clear proportional correlation between the extracted Cs and Sr in fractions for each soil and some of soils physicochemical properties. Organic matter appears to play an important role in the soil retention, particularly for Cs where the extracted percentage exceeds to 30% in whole soils. In contrast, strontium expresses a remarkable affinity for the fraction bound to carbonates. The obtained data also indicate that the availability of Cs in the four soils is less important compared to Sr availability. This is illustrated by the higher value of extracted Sr in the easily extractible phase, including the water-soluble and the exchangeable fraction.     

固相萃取-原子荧光光谱法测定土壤中的砷

采用硝酸-氢氟酸-盐酸体系微波消解土壤并结合On-Guard ⅡH柱去除消解液中重金属,原子荧光光谱法测定土壤中的砷。本方法前处理操作过程简单、省时、省力、酸用量少,砷的加标回收率为94.4％～105.6％,能够满足环境监测分析的要求。