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1.
采用吹扫捕集—气相色谱—质谱联用技术分析水中的24种挥发性有机物。通过优化分析条件,改善了各组份的分离效果,节省了分析时间,得到各组份检测限为0.001-0.099μg/L,相对标准偏差为2.3%-5.6%,加标回收率为91.2%-107.6%,方法具有较好的精密度、准确度和低检测限。同时对漳州市饮用水源中的24种挥发性有机物进行监测分析,结果均低于检测限。  相似文献   

2.
气相色谱法分析挥发性卤代烃的柱优选   总被引:3,自引:0,他引:3  
本文优选出符合我国“水中优先控制污染物黑名单”中挥发性卤代烃测定的色谱柱DC-550。该柱可将在OV-101柱上重叠在一起的三氯乙烯和一溴二氯甲烷完全分离,满足我国对水和废水中挥发性卤代烃的测定。  相似文献   

3.
报导了用离子色谱法同时测定水中F~-,Cl~-、NO_3~-和SO_4~(2-)的最佳分析条件;研究了各组分测定的精密度,准确度,检测限和线性范围。用本法分析样品,获得了满意的结果。  相似文献   

4.
石河子市地下水环境背景值   总被引:11,自引:0,他引:11  
采集并测定了石河子市19个地下水背景水样,分别确定了该市潜水和承压—自流水中K+、Na+、Ca2+、Mg2+、Cl-、SO、HCO、NO、F-、总硬度、矿化度、可溶性SiO2、COD、pH、Cu、Pb、Zn、Cd、Mn、V、Li、Mo、Se、Hg、I、As、Cr+5、C6H5OH、CN-、ABS的环境背景值.  相似文献   

5.
用毛细管胶束电动色谱柱端安培检测的方法对对氧磷、甲基对硫磷、乙基对硫磷、扑灭松等四种常见有机磷农药进行了分离检测,对缓冲液种类、离子浓度、pH值、胶束浓度、电极的检测电势等检测条件进行了最佳优化。结果表明,此方法对四种农药的质量检测限较气相色谱法低3~4个数量级,并将用于地表水样品的检测。  相似文献   

6.
水中微量五氯酚的气相色谱法测定   总被引:1,自引:0,他引:1  
提出GC-FCD分析方法测定水中微量五氯酚残留量。水样经萃取分离、衍生后,采用石油醚提取醋酸五氯酚酯,然后进入色谱柱,柱内填充2%OV-17+2%QF-1/ChromosorbW-HP(80~100目),柱温200℃,N_2流量80mL/min,五氯酚酯3min内出峰,最低检测浓度为0.1μg/L,各种样品回收率均在90%以上,样品测试结果满意,可用于多种水体中微量PCP残留量的测定。  相似文献   

7.
火焰调零补偿法:1.每次做样前先用火焰调零测得空白溶液的吸光度为A1,其对应浓度为C1,再用空白溶液调零后测标准溶液系列,且测得试样吸光度A2,其对应浓度为C2,则待测离子的准确浓度C=C2+C1。C1求法:①因斜率相同,直接在用空白溶液调零制作的标准曲线上由A1查得C1或计算得到。②用火焰调零后测4个不同标准溶液吸光度,用标准加入法求得。2.先用空白溶液调零制作标准曲线,不改变仪器条件再用火焰调零后测定试样,其吸光度对应的浓度即为试样的准确浓度。本法甚至用一次蒸馏水也可准确测定大气降水中Na离…  相似文献   

8.
本文对蒸发浓缩法用于地面水中低浓度COD的测定作了研究,实验结果表明,地面水中COD物质在碱性条件下,能得以定量浓缩,然后采用重铬酸钾法进行测定,所得结果的精密度和准确度良好,若通过蒸发浓缩处理使COD物质浓缩5倍,则可使重铬酸钾法的最低检测限浓度由50mg/L降低到10mg/L,从而使该方法能够适用于地面水水质标准中各类水质COD检测要求。  相似文献   

9.
测定水中Cl- 一般采用AgNO3滴定法 ,当AgCl定量沉淀后 ,过量一滴AgNO3溶液与指示剂CrO2 -4 生成砖红色Ag2 CrO4沉淀 ,即为滴定终点。在此方法中 ,经典空白实验能有效控制和校正试剂中杂质、器皿及操作过程中沾污等因素对分析结果的影响 ,但它在校正误差时 ,也存在一些不足。(1 )水样滴定到终点是由乳白色变成砖红色 ,而经典空白实验是由透明的黄色转变成砖红色 ,两者色调变化不尽相同。因此 ,测试者对空白滴定终点易产生判断误差。(2 )水样滴定过程生成的AgCl沉淀对Cl- 有较强的吸附 ,而空白实验中消耗AgNO…  相似文献   

10.
应用离子色谱法对F^-、Cl^-、NO2^-、PO4^3-与BF4^-进行了分离,实现了工业废水中BF4^-的测定,具有检测限低、线性范围宽、分析时间短等特点。  相似文献   

11.
456 water samples collected from 152 water sources in 2006 were analyzed for 21 volatile organic compounds (VOCs). Concentrations of 21 VOCs ranged from below method detection limits of the laboratory to 7.65 ??g/L (toluene), but seldom exceeded the concentration limits set in the National Drinking Water Quality Standards (GB5749-2006) or the National Environmental Quality Standards for Surface Water (GB3838-2002) of China. Of the 21 individual VOCs analyzed, 11 VOCs were detected in at least one sample at or above 1.0 ??g/L; 6.6% of the water samples had a detection of at least one VOC at or above 1.0 ??g/L, and 2.6% had a detection of at least two VOCs at or above 1.0 ??g/L. Based on the statistical data of detection frequencies above the method detection limits, 75% of the samples detected at least one VOC, and 65% of the samples detected at least two VOCs. Chloroform, toluene, and 1,2-dichloroethene were the three most frequently detected VOCs, with detection frequencies of 76.97%, 68.42%, and 44.08%, respectively. Volatile halogenated hydrocarbons and gasoline components were the two most frequently detected VOC groups.  相似文献   

12.
建立QuEChERS-气相色谱法同时检测土壤中8种有机氯农药的方法,优化分散固相萃取剂用量。土壤样品通过分散固相萃取净化技术,氮吹浓缩后用正己烷定容,最后通过气相色谱测定。结果表明,在2.0~100μg/L质量浓度范围内呈线性,相关系数r为0.9895~0.9991。空白样品在0.5,5和20μg/kg加标浓度下的回收率为75.3%~92.3%,相对标准偏差为3.2%~5.6%(n=5),方法检出限为0.053~0.064μg/kg,测定下限为0.21~0.26μg/kg。该方法操作简单、结果准确、有机试剂用量少、分析成本低,适用于土壤中有机氯农药的残留检测与分析。  相似文献   

13.
14.
The application of geostatistics to spatial interpolation of time-invariant properties in ground-water studies (such as transmissivity or aquifer thickness) is well documented. The use of geostatistics on time-variant conditions such as ground-water quality is also becoming more commonplace. Unfortunately, the detection of temporal changes in spatial correlation through direct comparison of experimental semivariograms is difficult due to the uncertainty in sample semivariograms constructed from field data. This paper discusses the use of the jackknife approach to estimate confidence limits of semivariograms of trichloroethane (TC) and other volatile organic compounds (VOC) in contaminated ground-water in northern Illinois. Examination of the spread of the confidence limits about the semivariograms created from two types of sampling networks are discussed.  相似文献   

15.
In the summer of 2003, ambient air concentrations of volatile organic compounds (VOCs) were measured at 12 sites within a 3-km radius in Deer Park, Texas near Houston. The purpose of the study was to assess local spatial influence of traffic and other urban sources and was part of a larger investigation of VOC spatial and temporal heterogeneity influences in selected areas of Houston. Seventy 2-h samples were collected using passive organic vapor monitors. Most measurements of 13 VOC species were greater than the method detection limits. Samplers were located at 10 residential sites, a regulatory air monitoring station, and a site located at the centroid of the census tract in which the regulatory station was located. For residential sites, sampler placement locations (e. g., covered porch vs. house eaves) had no effect on concentration with the exception of methyl tertiary-butyl ether (MTBE). Relatively high correlations (Pearson r > 0.8) were found between toluene, ethylbenzene, and o,m,p-xylenes suggesting petroleum-related influence. Chloroform was not correlated with these species or benzene (Pearson r < 0.35) suggesting a different source influence, possibly from process-related activities. As shown in other spatial studies, wind direction relative to source location had an effect on VOC concentrations.  相似文献   

16.
采用高效液相色谱法测定鸡蛋清和蛋黄中磺胺嘧啶、磺胺吡啶、磺胺二甲基嘧啶、磺胺甲氧哒嗪、磺胺甲恶唑、磺胺间甲氧嘧啶、磺胺喹恶啉等7种磺胺类药物残留,优化了色谱条件和样品预处理方法。7种磺胺类药物在0.050 mg/L~10.0 mg/L范围内线性良好,检出限和定量限分别低于0.02 mg/kg和0.04 mg/kg。在0.250 mg/kg和0.500 mg/kg两个添加水平,蛋清中的回收率为81.0%~100%,RSD为0.8%~4.8%,蛋黄中的回收率为72.2%~94.1%,RSD为1.1%~6.9%。  相似文献   

17.
采用加速溶剂萃取—气相色谱法对土壤中20种有机氯农药进行了提取测定.通过改变加速溶剂萃取条件,选取了最佳条件参数,减少了组份的损失;通过改变气相色谱条件,使得20种有机氯农药快速分离.该方法具有操作简便、灵敏度高、检出限低、快速、溶剂消耗少等优点,方法检出限为1.23~ 3.11 μg/kg,实际样品的加标回收率为62.3%~119.7%.  相似文献   

18.
用金矿废渣样品进行氰化物的浸提试验,对浸提剂的pH值、浸提次数等条件进行优化。经实际样品验证,确定pH值〉12的碱性水溶液为最佳浸提剂,浸出液中易释放氰化物和总氰化物可用硝酸银滴定法或异烟酸一巴比妥酸分光光度法测定,方法检出限分别为0.25mg/L、0.001mg/L,加标回收率为90.0%~92.0%,测定结果的RSD〈8%。  相似文献   

19.
A dual channel gas chromatograph with flame ionisation detectors has been used extensively for analysis of volatile organic compounds in the atmosphere and forms the basis of two monitoring instruments contributing VOC data to the World Meteorological Organisation - Global Atmosphere Watch network. Recent modifications to the methodology have broadened the scope of the instrument; to incorporate measurements of selected monoterpenes, and achieve improved accuracy in the measurement of oxygenated volatile organic compounds. Analysis of selected monoterpenes has been achieved without any significant loss of resolution of the non-methane hydrocarbons or oxygenated compounds. Quantification of 64 different VOCs of varying functionalities are reported with detection limits in the range 1-5 parts per trillion. Here we present a summary of the instrumental and calibration details for the methodology, which continues to be used on many field projects, along with a discussion of the associated measurement uncertainties.  相似文献   

20.
微波萃取-气相色谱法测定土壤中有机氯残留   总被引:3,自引:0,他引:3       下载免费PDF全文
采用微波萃取-硅镁吸附剂净化-气相色谱法测定土壤中有机氯农药,优化了试验条件。方法线性良好,8种有机氯农药的检出限为0.09ng/g-0.62ng/g,样品测定的RSD为2.6%-13.2%,基质加标平均回收率为93.7%-112%,质控样的测定结果与参考值相吻合。  相似文献   

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