共查询到20条相似文献，搜索用时 46 毫秒
1.
常压微波技术萃取土壤中有机氯农药 总被引：7，自引：3，他引：7
利用常压微波萃取技术提取土壤样品，经佛罗里硅土柱净化后用气相色谱检测（电子捕获检测器）其中13种有机氯农药。试验了丙酮／正己烷混合溶液的提取条件，考察了提取时间、提取温度和提取功率对提取效率的影响，并与索氏提取及超声波提取进行比较。在优化的萃取条件下，常压微波萃取20min重复测定的平均回收率为84．26％-105．2％，相对标准偏差（RSD，n=5）为0．52％-18．6％。方法的检出限为0．033—0．853ng／g。 相似文献
2.
C18固相膜萃取-气相色谱法测定饮用水中12种有机氯农药 总被引：13，自引：10，他引：13
利用C18固相萃取膜提取水样，气相色谱法（电子捕获检测器）测定饮用水中12种有机氯农药。对洗脱液、水样pH值、萃取压力等条件进行了优化选择，并与液-液萃取做了比较。结果表明，与液-液萃取相比，固相膜萃取具有操作简单、富集倍数高、节省溶剂和耗时短等优点，是萃取水中有机氯农药的有效方法。12种有机氯农药的回收率为85．97％～127．7％，相对标准偏差（RSD，n=5）为4．74％～12．2％，方法检出限为0．014～0．047μg/L。 相似文献
3.
研究了聚乙二醇-2000水溶液在硫酸铵存在下分为液-液两相的条件和二溴羧基偶氮氯膦与Pd（Ⅱ）反应生成的配合物在该萃取体系两相间的分配行为，实现了Pd（Ⅱ）的定量萃取分离。在此基础上建立了非有机溶剂液-液萃取分光光度法测定微量Pd（Ⅱ）的新方法。该方法的检出限为0．03mg／L，线性范围为0．09～2．0mg／L，在最佳实验条件下，萃取率达94％。方法用于铂钯二次精矿和人工合成样品中微量钯的测定，相对标准偏差（RSD，n=5）≤2．4％，加标回收率为96％-103％。 相似文献
4.
研究了碘化钾-甲基异丁基甲酮（KI—MIBK）萃取-火焰原子吸收分光光度法连续测定地球化学样品中痕量银、镉和铊的主要条件。通过对火焰原子吸收分光光度计气路控制系统及雾化器的改进，较大地改善了萃取-火焰原子吸收分光光度法测定银、镉和铊的稳定性和灵敏度。选择萃取酸度为1．2mol／L HCl、水相和有机相体积配比为3：1～4：1，方法精密度（RSD，n=12）为Ag4．5％～9．6％、Cd1．5％～7．9％、T14．5％～5．4％，检出限（3s）为Ag0．004μg/g、Cd0．007μg／g、T10．011μg/g，符合多目标地球化学调查样品测试及质量监控要求。用国家一级标准物质和密码组合标准物质进行验证，测试结果令人满意。 相似文献
5.
目的：探讨紫外分光光度法测定秋水仙碱中毒血清,为临床秋水仙碱中毒提供诊疗依据。方法取0．5 mL 血清加提取液（三氯甲烷∶甲醇＝95∶5）4．0 mL。充分震荡萃取,高速离心,取有机层于另一试管中氮气吹干,取0．2 mL 甲醇溶解残渣,混匀,取50 mL 做紫外扫描。结果血清中秋水仙碱最大吸收峰（351±1）nm,浓度在5．0～40μg／mL 范围内呈线性,回归方程Y ＝0．0502X ＋0．0013,其相关系数为0．9995,回收率为83．8％～102．8％,相对标准差为3．3％～4．8％。日内、日间相对标准差分别为3．22％～4．74％和3．45％～4．66％,最低检出浓度为1．0μg／mL。结论该方法操作简便,分析快速,结果准确,为临床诊断秋水仙碱中毒提供了一个简便准确的检测方法。 相似文献
6.
水杨基荧光酮-石蜡相分光光度法测定植物中痕量锗 总被引：1，自引：0，他引：1
介绍了以锗-水杨基荧光酮-石蜡为体系,石蜡相分光光度法测定植物中的锗,探讨了该方法的最佳实验条件。结果表明,在HCl介质中,锗与水杨基荧光酮形成的络合物被萃取至蜡相后,于506 nm处有最大吸收,其εmax=2．3×105L·mol-1·cm-1,锗含量在0-0．40 mg／L 符合比尔定律,精密度(RSD,n=8)为2．7％-4．3％,回收率为96%-110％。方法应用于植物中锗的测定,结果满意。 相似文献
7.
木质素分解产物酚类化合物是指示海洋环境中陆源有机碳来源的重要生物标志物,因此,开发检测海洋沉积物中木质素分解产物酚类化合物的简便方法,对研究海洋有机碳的来源及生物地球化学循环过程具有重要意义。本文采用固相萃取（SPE）和超高效液相色谱-飞行时间质谱技术(UHPLC-TOF/MS),建立了一种同步测定海洋沉积物中木质素分解产物酚类化合物（11种）的方法。首先对海洋沉积物样品进行氧化铜氧化碱分解和SPE净化处理,再采用填料粒径为1.8μm的反相C18柱进行分离,电喷雾TOF/MS全扫描模式检测,内标法定量。结果表明：沉积物中木质素的11种主要分解产物酚类化合物在20min内分离良好;方法具有良好的精密度（相对标准偏差RSD均小于9.0%）,在线性范围内相关系数（R2）均不小于0.9989,加标回收率在86.8%～93.2%之间。应用该方法对莱州湾表层沉积物中木质素分解产物酚类化合物进行测定,12个表层沉积物样品中11种目标化合物的检出率均为100%;相关诊断比值：肉桂基酚系列单体总量与香草基酚系列单体总量的比值C/V在0.18～0.81之间,均值为0.38;丁香基酚系列单体总量与香草基酚系... 相似文献
8.
以碳酸钙共沉淀卤水中的痕量Cu、Pb、Zn，用火焰原子吸收光谱法测定。对试剂的加入量、富集时间、酸度等影响因素进行了实验，选择了最佳的共沉淀条件。方法已用于卤水分析，加标回收率为Cu94．0％～97．6％、Pb94．0％。102％、Zn93．4％-102％。对卤水样品6次测定的相对标准偏差为Cu0．49％、Pb0．79％、Zn1．85％。 相似文献
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10.
微波溶样-自动电位滴定法测定铁矿石中全铁量 总被引：1，自引：1，他引：1
将微波消解溶样技术与自动电位滴定相结合，用于铁矿石中全铁量的测定，检测结果与ISO9507方法的结果相符。对微波溶样的时间和压力进行了选择。方法对4个不同全铁浓度段的铁矿石国家一级标准物质中的全铁量测定12次，结果的平均值与标准值的相对误差为0．18％-0．29％，相对标准偏差为0．10％-0．18％。方法减少了操作人员的劳动强度，缩短了分析时间。 相似文献
11.
Gilles Serge Odin 《Comptes Rendus Geoscience》2002,334(6):409-414
Lithostratigraphy, physicochemical stratigraphy, biostratigraphy, and geochronology of the 77–70 Ma old series bracketing the Campanian–Maastrichtian boundary have been investigated by 70 experts. For the first time, direct relationships between macro- and microfossils have been established, as well as direct and indirect relationships between chemo-physical and biostratigraphical tools. A combination of criteria for selecting the boundary level, duration estimates, uncertainties on durations and on the location of biohorizons have been considered; new chronostratigraphic units are proposed. The geological site at Tercis is accepted by the Commission on Stratigraphy as the international reference for the stratigraphy of the studied interval. To cite this article: G.S. Odin, C. R. Geoscience 334 (2002) 409–414. 相似文献
12.
Inter-regional correlation of transgressions and regressions in the Cretaceous period 总被引：1，自引：0，他引：1
T. Matsumoto 《Cretaceous Research》1980,1(4):359-373
Well investigated platforms have been selected in each continent, and the history of Cretaceous transgressions and regressions there is concisely reviewed from the available evidence. The factual records have been summarized into a diagram and the timing of the events correlated between distant as well as adjoining areas.On a global scale, major transgressions were stepwise enlarged in space and time from the Neocomian, via Aptian-Albian, to the Late Cretaceous, and the post-Cretaceous regression was very remarkable. Minor cycles of transgression-regression were not always synchronous between different areas. Some of them were, however, nearly synchronous between the areas facing the same ocean.Tectono-eustasy may have been the main cause of the phenomena of transgression-regression, but certain kinds of other tectonic movements which affected even the so-called stable platforms were also responsible for the phenomena. The combined effects of various causes may have been unusual in the Cretaceous, since it was a period of global tectonic activity. The slowing down of this activity followed by readjustments may have been the cause of the global regression at the end of the Cretaceous. 相似文献
13.
The Afyon stratovolcano exhibits lamprophyric rocks, emplaced as hydrovolcanic products, aphanitic lava flows and dyke intrusions, during the final stages of volcanic activity. Most of the Afyon volcanics belong to the silica-saturated alkaline suite, as potassic trachyandesites and trachytes, while the products of the latest activity are lamproitic lamprophyres (jumillite, orendite, verite, fitztroyite) and alkaline lamprophyres (campto-sannaite, sannaite, hyalo-monchiquite, analcime–monchiquite). Afyon lamprophyres exhibit LILE and Zr enrichments, related to mantle metasomatism. 相似文献
14.
正20140751 Guo Xincheng(Geological Party,BGMRED of Xinjiang,Changji 831100,China);Zheng Yuzhuang Determination and Geological Significance of the Mesoarchean Craton in Western Kunlun Mountains,Xinjiang,China(Geological Review,ISSN0371-5736,CN11-1952/P,59(3),2013,p.401-412,8 相似文献
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正20141058 Chen Ling(Key Laboratory of Mathematical Geology of Sichuan Province,Chengdu University of Technology,Chengdu610059,China);Guo Ke Study of Geochemical Ore-Forming Anomaly Identification Based on the Theory of Blind Source Separation(Geosci- 相似文献
16.
正20141334 Chen Kun(Institute of Geophysics,China Earthquake Administration,Beijing100081,China);Yu Yanxiang Shakemap of Peak Ground Acceleration with Bias Correction for the Lushan,Sichuan Earthquake on April20,2013(Seismology and Geology,ISSN0253-4967,CN11-2192/P,35(3),2013,p.627-633,2 illus.,1 table,9 refs.)Key words:great earthquakes,Sichuan Province 相似文献
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正20141624 Cai Xiongfei(Key Laboratory of Geobiology and Environmental Geology,Ministry of Education,China University of Geosciences,Wuhan 430074,China);Yang Jie A Restudy of the Upper Sinian Zhengmuguan and Tuerkeng Formations in the Helan Mountains(Journal of Stratigraphy,ISSN0253-4959CN32-1187/P,37(3),2013,p.377-386,5 illus.,2 tables,10 refs.) 相似文献
18.
正20142263Lü Shaojun(Geological Survey of Jiangxi Province,Nanchang 330030,China)Early-Middle Permian Biostratigraphical Characteristics in Qiangduo Area,Tibet(Resources SurveyEnvironment,ISSN1671-4814,CN32-1640/N,34(4),2013,p.221-227,2illus.,2tables,22refs.)Key words:biostratigraphy,Lower Permian,Middle Permian,Tibet 相似文献
19.
正20142560Hu Hongxia(Regional Geological and Mineral Resources Survey of Jilin Province,Changchun 130022,China);Dai Lixia Application of GIS Map Projection Transformation in Geological Work(Jilin Geology,ISSN1001-2427,CN22-1099/P,32(4),2013,p.160-163,4illus.,2refs.) 相似文献
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正20140692 Duo Tianhui(No.402 Geological Team,Exploration of Geology and Mineral Resources of Sichuan Authority,Chengdu611730,China);Wang Yongli Computer Simulation of Neptunium Existing Forms in the Groundwater(Computing Techniques for Geophysical and Geochemical Exploration,ISSN1001-1749,CN51-1242/P,35(3), 相似文献