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建立了基于分子络合的分散液液微萃取(DLLME)方法,以磷酸三丁酯为萃取剂,以甲醇为分散剂,与高效液相色谱联用检测了环境水样中麦草畏和2,4-二氯苯氧乙酸(2,4-D酸)2种苯氧羧酸类除草剂,对影响前处理效果的因素(包括水样的pH值、萃取剂的种类和体积、分散剂的种类和体积、反萃液的pH值、反萃液的体积和盐浓度等)进行了详细考察,在最佳萃取条件下(水样体积10 mL,水样的pH值为0~1.0、100 μL磷酸三丁酯萃取剂、1000 μL甲醇分散剂、0.01 mol/L的氢氧化钾反萃液的体积为80 μL),2种苯氧羧酸类除草剂在0.50~1000 μg/L范围内具有良好的线性,相关系数不小于0.9985,麦草畏和2,4-D酸的检出限分别为0.44 μg/L和0.49 μg/L,富集倍数分别为85和90,在实际样品中的加标回收率为75.7%~104.0%。该方法基于分子络合反应机理,将新型萃取剂磷酸三丁酯应用于分散液液微萃取,与HPLC联用实现了麦草畏和2,4-D酸的富集与检测,为环境水样中苯氧羧酸类除草剂的检测提供了新的前处理方法。 相似文献
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含表面活性剂水溶液中的乙酸丁酯、磷酸三丁酯的毛细管气相色谱定量分析 总被引:2,自引:0,他引:2
乙酸丁酯、磷酸三丁酯均是工业中常用的萃取剂,加入表面活性剂后,它们在水中的溶解度会有较大增加.通过对水中的乙酸丁酯、磷酸三丁酯的定量分析可以为研究萃取剂的流失机理提供数据,从而指导生产.常用的气相色谱分析方法是用有机溶剂萃取后,对有机相进行分析.但由于某些表面活性剂存在,加入有机溶剂会产生乳化,产生较大误差.对此本文采用毛细管气相色谱法研究建立了对含有阴、阳离子,非离子表面活性剂水溶液中的乙酸丁酯、磷酸三丁酯的定量方法,结果表明,这是一种快捷、准确、简便的分析方法. 相似文献
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在前文中曾用反相纸层析研究了中性萃取剂磷酸三丁酯萃取铀酰离子的机理,并指出在纸上存在高沸点溶剂时可以测得准确的结果.现用酸性萃取剂二(2-乙基己基)磷酸(HDEHP)作为固定相进行反相纸层析. 相似文献
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采用场放大进样(FASI)-毛细管电泳非接触式电导检测法(CE-C4D),结合液液萃取(LLE)的样品净化预处理技术,分离检测了酱油中人工合成甜味剂安赛蜜。酱油样品经酸化后,用乙酸乙酯作为萃取剂,成功地消除了酱油中含有的大量无机盐等复杂基体对微量安赛蜜的干扰。实验对影响LLE萃取效率和FASI-CE-C4D分离检测的关键因素进行了讨论,特别是对样品净化前处理过程中萃取剂及用量、样品酸化pH值、萃取时间、萃取温度等条件进行了优化。结果表明,酱油中的安赛蜜可获得良好分离和灵敏检测,检出限和定量限分别为0.15 mg/kg和0.48 mg/kg。对市售酱油样品进行安赛蜜的加标回收测定,得到加标回收率为92.3%~108.1%,相对标准偏差<8.0%。该法具有简单快速、灵敏高效、分析成本低的优点,能满足酱油中安赛蜜的分析检测要求。 相似文献
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测定了15℃时丙酸,15℃及30℃时丁酸和15℃时乙、丙、丁混合酸在乙酸乙酯和水中的液-液相平衡数据。也测定了乙酸-丙酸,丙酸-丁酸及乙酸-丁酸三个二元系统在760毫米汞柱压力时的汽-液平衡。我们认为汽-液平衡的非理想主要是由于汽相分子的缔合。于是推导了计算分子缔合时的汽-液平衡关系式,推算的乙酸-丁酸二元系统的汽-液平衡数据和实验结果相符合。 相似文献
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微波萃取-高效液相色谱法测定茶叶中儿茶素和咖啡因 总被引:2,自引:0,他引:2
选用乙酸乙脂为萃取剂,采用微波技术萃取茶叶中表没食子儿茶素、儿茶素、表儿茶素及咖啡因(CAF),用高效液相色谱法(HPLC)法测定。通过正交试验,得到微波萃取四组分总量的最佳条件为萃取温度100℃,萃取时间10min,浸润水与乙酸乙酯体积比1:8,其相对标准偏差和回收率分别为2.1%~2.4%和54.2%~100.1%。 相似文献
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建立了阀切换-离子色谱法测定1,2-环氧丁烷(1,2-BO)产品中有机酸(甲酸、乙酸和丙酸)的方法。样品经乙醇稀释后,通过阀切换技术,有机酸被IonPac TAC-ULP1捕集柱捕集,然后进入IonPac AS11分析柱分离,并由电导检测器检测。结果表明:甲酸、乙酸和丙酸均能实现较好地分离,在各自的范围内其色谱峰面积呈现良好的线性关系。实际样品的加标回收率为92.5%~111.8%,相对标准偏差小于5.6%(n=3),检出限为0.60~4.80 μg/L。该方法具有前处理简单、快速、准确等特点,适用于不溶于水的有机体系中有机酸的分析。 相似文献
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典型全氟有机酸类化合物的样品前处理与分析方法研究进展 总被引:2,自引:0,他引:2
全氟辛烷磺酸(PFOS)和全氟辛烷羧酸(PFOA)是两种典型的全氟有机酸类化合物,也是全氟化合物(PFCs)前体物的最终降解产物,具有肝毒性、胚胎毒性、生殖毒性、神经毒性,检出率最高。在各种被污染的介质中,PFOS和PFOA含量往往很低,基体复杂多样,快速高效的样品前处理技术成为测定的关键环节。目前,国际上对PFOS和PFOA的测定无统一标准,而我国关于PFCs的分析研究落后于国际发展水平。该文介绍了PFOS和PFOA的特性,系统总结和评述了前处理技术(液液萃取、固相萃取、固相微萃取、超声萃取和QuEChERS法)及分析方法(色谱-质谱方法、光谱法、酶联免疫法和电化学法),以期为PFOS和PFOA的分析监测及标准制定提供参考。 相似文献
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A novel sensor for acetic acid vapour determination is proposed. This sensor is based on a piezoelectric crystal covered with a film of diethylenetriamine. For the sensor development a system of our own design-consisting of testing chamber, oscillator circuit and measure instruments-has been employed. The sensor shows its activity to the acetic acid vapours for more than 60 days. The selectivity is adequate although some vapours interfere: hydrochloric acid, formic acid, formaldehyde, tributyl phosphate, chloroform, chlorobenzene, acetone and isobutylmethylketone. The sensor described can be applied to detect acetic acid vapours in the presence of other vapours: acetonitrile, acrolein, benzene, n-hexane, ethanol, propanol, n-butyl acetate, isopropyl ether, isoamyl alcohol, ethyl ether, methylene chloride, carbon tetrachloride and toluene. The major advantages of the proposed sensor over other existing techniques are its simplicity, reduced cost and capacity for use in situ. 相似文献
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N. G. Yakovlev V. N. Kosyakov G. M. Kazakova 《Journal of Radioanalytical and Nuclear Chemistry》1982,75(1-2):113-120
Extraction of Bk(IV), Ce(IV), Pu(IV) and Zr by tributyl phosphate from 2M to 16M nitric acid solutions has been studied. Using the data on the effect of the extractant, nitric acid and nitrate ion concentrations on the distribution coefficients of Bk(IV) and Ce(IV), the mechanism of Bk(IV) extraction by tributyl phosphate from nitric acid solutions is considered. 相似文献
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P. T. Sukhanov S. P. Kalinkina Ya. I. Korenman 《Journal of Analytical Chemistry》2007,62(12):1122-1125
The extraction of phenol and 1-naphthol with isomolar mixtures of ethyl acetate and hexane under batch conditions and with tributyl phosphate impregnated into a polyurethane foam under batch and dynamic conditions was studied. A procedure for determining phenol and 1-naphthol in aqueous samples was developed including their dynamic recovery on a column packed with polyurethane foam impregnated with tributyl phosphate, elution with a 0.1 M NaCl solution of pH 12.5–13.0, extraction with a mixture of ethyl acetate and hexane, and separation by normal-phase high-performance liquid chromatography (HPLC) with UV-detection. The overall preconcentration coefficient was 250. The detection limits were 2.5 μg/L. The relative error of determination was lower than 18%. The time of one determination was 2–2.5 h. 相似文献
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《Fluid Phase Equilibria》1999,155(2):287-296
Vapor–liquid equilibria were measured at 101.3 kPa, in a range of temperatures from 350.28 to 374.69 K, for five binary mixtures formed by nitromethane with ethyl acetate, propyl acetate, isopropyl acetate, methyl propionate, and ethyl propionate. Calculations of nonideality of the vapor phase were made with Soave–Redlich–Kwong equation of state. Thermodynamic consistency of data was tested via Herington analysis. Two systems show minimum boiling azeotropes. The experimental VLE data were reduced and binary parameters for four liquid models, such as van Laar, Wilson, NRTL and UNIQUAC, were fitted. A comparison of model performances was made by using the criterion of average absolute deviations in boiling point and in vapor-phase composition. 相似文献
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A method has been developed for the determination of phosphorus, as phosphate, by means of the catalytic polarographic wave for the reduction of hydrogen peroxide in the presence of Mo(VI). This reduction is combined with the previous formation and extraction of 12-molybdophosphoric acid. Depending on the extractant chosen, ethyl acetate or methyl isobutyl ketone, the determination limit is 2.3 or 3.1 mug l . respectively. The procedure has been applied to certified steel samples with good results. 相似文献
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《液相色谱法及相关技术杂志》2012,35(13):2921-2936
Abstract Three chromatographic methods for determining p-hydroxy-phenytoin (p-HPT) in urine were compared: (1) GC with derivatisation of the samples, (2) HPLC after extraction with ethyl acetate and (3) HPLC using a column switching system for direct injection of samples. In all three methods the p-HPT glucuronides were first hydrolysed using concentrated mineral acid at boiling point. For method (1) the acidic hydrolysate was adjusted to pH 7–8.5. Benzenetetrahydrofuran was used for extraction of p-HPT. The extract was evaporated to dryness, taken up in trimethyl-aniliniumhydroxide and injected. For method (2) the acidic hydrolysate was buffered with tri-sodium phosphate. An aliquot of the buffered solution was extracted with ethyl acetate. The extract was evaporated to dryness, taken up in methanol and injected. For method (3) the hydrolysate was diluted with water/acetonitrile (9:1), centrifuged and directly injected onto the pre-column for the sample washing step. 相似文献
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I. S. El-Yamani E. N. Abd El-Messieh 《Journal of Radioanalytical and Nuclear Chemistry》1989,129(2):435-442
The distribution of beryllium between aqueous sulfuric acid/potassium iodide solutions and organic phases of tributyl phosphate is described. The dependence of extraction on the pH of the aqueous phase, metal and extractant concentration, diluent type and organic additive, has been investigated. Extraction mechanism is discussed on the basis of results obtained. A method for the separation and determination of beryllium, in a mixture of beryllium and aluminium (with other contaminants) is outlined. 相似文献