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用毛细滴管数滴微型滴定法对碘离子进行测定。经评定,该法不确定度Urel(C)约为1.27%,与常量法相当,对照试验也显示该法符合国家标准。该法以自制的液滴体积为0.01~0.02 mL的聚乙烯毛细滴管就地进行滴定。其主要仪器外形小巧、便于携带,滴定快速、准确,滴定剂用量仅为65~100滴。 相似文献
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用EDTA微量滴定法测定了水中硫酸根及总硬度,测定过程在氨性缓冲介质中进行,采用络黑T作指示剂,用一种自制的聚乙烯微型毛细管滴定管进行滴定,滴定反应所耗的滴定剂用计滴法计数。从微滴管流出的每一小滴滴定剂的体积(通常在0.01~0.02mL之间)用重量法校正,每次滴定所耗滴定剂一般在50~200小滴之间。此方法的扩展不确定度,对硫酸根测定为0.94%与重量法相当,而精密度则优于重量法,对总硬度测定为0.82%优于常量滴定法。此方法的特点为分析快速、准确,消耗试剂少且便于携带,适合于现场或野外分析应用。 相似文献
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以自制的液滴体积为0.01—0.02mL的聚乙烯毛细滴管对水中硫酸根离子含量进行数滴分析,其主要仪器外形小巧、便于携带,滴定快速、准确,试剂消耗量约为常量法的5%,滴定剂用量约为50—200滴。该法的优点是仪器携带方便,适用于水中硫酸根离子含量的室外快速分析。 相似文献
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蔡成翔 《理化检验(化学分册)》2007,43(9):740-743,746
与不锈钢及玻璃相比,聚乙烯是制作毛细管微滴定管的合适材料。所制成的微滴定管应用于计滴微量滴定法中,并通过食醋中总酸度的测定,食盐中碘酸盐的测定,水的总硬度测定及水中溶解氧的测定等4种方法中的应用对其适用性作了考核,对计滴微量滴定法测定食醋的总酸度的测量不确定度作了评定。如试验数据所示,从微滴定管流出的滴定剂每滴的体积在0.01~0.02 mL之间。如果一次滴定所耗滴定剂总量在70~110滴(约1 mL)之间,上述4种测定方法所得结果的RSD值(n=6)在0.6%~1.8%之间,回收率试验的结果在99.4%~101.4%之间,食醋中总酸度测定的扩展相对不确定度评定为1.0%。此外,与常规的常量滴定法相比,用毛细滴管的计滴微量滴定法具有等同的准确度和精密度,而在方便携带,成本低廉及操作简便、快速等方面却大大优于前者。 相似文献
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极弱酸碱的直接电位滴定 总被引:4,自引:0,他引:4
讨论了用两点电位滴定法直接测定pKn(或pKb)在10左右的极弱酸碱的可行性。该法只需在计量点后适当位置测定两组滴定数据,即可确定滴定计量点。与线性电位滴定法比较,两者结果一致。 相似文献
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提出了可见光光谱滴定法测定水中总硬度的方法。在整个滴定过程采用颜色真实测量体系替代人的感官判定,建立了光谱计量参数与试剂量的色变滴定曲线,用曲线上的突变峰标识滴定终点或结构变化点。可见光光谱滴定法可以克服感官滴定存在色评价条件不统一、操作人员个体生理条件不一致、无法量值溯源等困难,能实现测定的自动化。上述方法用于测定水质总硬度标准样品,结果显示测定值均在标准样品认定值的不确定度范围内。按照标准加入法对实际样品进行回收试验,回收率为99.7%~101%。分别采用可见光光谱滴定法和目视滴定法[即乙二胺四乙酸(EDTA)络合滴定法]测定8种水体样品的总硬度,配对t检验结果表明两种方法的测定结果无显著性差异。 相似文献
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蔡成翔 《理化检验(化学分册)》2007,43(10):844-846
将微量称量滴定法应用于硫代硫酸钠-碘量法测定水中溶解氧的含量.在滴定中采用自制的聚乙烯毛细滴定管代替了国标GB 10738-1989中所规定使用的结构复杂精细的称量滴定装置.操作时,在聚乙烯毛细滴定管中吸满了Na2S2O3标准溶液,在精密电子天平上称得滴定前后(以淀粉为指示剂)毛细滴定管及滴定剂的总质量.从滴定中所耗Na2S2O3标准溶液的质量按文中所给出的公式即可计算水样中的溶解氧含量,所制作的毛细管滴定管每滴滴定剂的质量要求控制在0.005~0.010 g之间,滴定过程的相对偏差可控制在1.0%左右.由于滴定系在微量水平上进行,因此方法具有消耗试剂少,操作快速而方便,且能取得优于国标方法的准确度和精密度,对4个水样进行分析,测得结果的相对标准偏差值(n=7)在0.18%~0.66%之间,明显小于国标方法测定结果的相对标准偏差(0.43%~1.26%). 相似文献
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药用小苏打片中NaHCO3的微型滴定分析 总被引:2,自引:0,他引:2
药用小苏打片中NaHCO3的微型滴定分析杨左海(咸宁医学院化学教研室湖北437100关键词小苏打片碳酸氢钠微型滴定法常规滴定法中图分类号O655.22小苏打片为NaHCO3加淀粉等压制而成,用于碱化尿液及酸血症,也可用于胃酸过多。一般用常规滴定法检测... 相似文献
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建立了悬浮固化分散液液微萃取-毛细管电泳法同时测定水中磺酰脲类除草剂残留的方法。以十二醇为萃取剂、甲醇为分散剂,采用悬浮固化分散液液微萃取技术对水样进行分离提取,并结合毛细管电泳法进行测定。该方法可以有效提取、分离、检测水中残留的微量苯磺隆、吡嘧磺隆、苄嘧磺隆等9种磺酰脲类除草剂,各待测物在10.0~1000 μg/L范围内线性关系良好,相关系数r≥0.992,方法检出限为2.40~7.50 μg/L,方法精密度为6.55%~13.9%。将该方法用于实际水样的测定,取得了较满意的结果,加标回收率为82.0%~104%。该方法简便快速,适合水中磺酰脲类除草剂的同时测定。 相似文献
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Stuart A. Oehrle Roger D. Blanchard Chris L. Stumpf Debra L. Wulfeck 《Journal of chromatography. A》1994,680(2):645-652
Capillary ion electrophoresis (CIE) is a capillary electrophoretic technique which has been developed for the rapid analysis of low-molecular-mass inorganic and organic ions. Anion and cation analysis of wastewater samples from a meat processing plant will be discussed. The wastewater samples were collected above, at point of discharge, and at various points downstream from the plant. The purpose of the analysis was to investigate dilution effects of the wastewater as it mixes with the stream water. CIE allows for rapid analysis times (typically less than 5 min) with little sample preparation required. 相似文献
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In‐line coupled single drop liquid–liquid–liquid microextraction with capillary electrophoresis for determining fluoroquinolones in water samples
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A simple in‐line single drop liquid–liquid–liquid microextraction (SD‐LLLME) coupled with CE for the determination of two fluoroquinolones was developed. The method is capable to quantify trace amount of analytes in water samples and to improve the sensitivity of CE detection. For the SD‐LLLME, a thin layer of organic phase was used to separate a drop of 0.1 M NaOH hanging at the inlet of the capillary from the aqueous donor phase. By this way, the analytes were extracted to the acceptor phase through the organic layer based on their acidic/basic dissociation equilibrium. The drop was immersed into the organic phase during 10 min for extraction and then it is directly injected into the capillary for the analysis. Parameters such as type and volume of organic solvent phase, aqueous donor, and acceptor phases and extraction time and temperature were optimized. The enrichment factor was calculated, resulting 40‐fold for enrofloxacin (ENR) and sixfold for ciprofloxacin (CIP). The linear range were 20–400 μg/L for ENR and 60–400 μg/L for CIP. The detection limits were 10.1 μg/L and 55.3 μg/L for ENR and CIP, respectively, and a good reproducibility was obtained (4.4% for ENR and 5.6% for CIP). Two real water samples were analysed applying the new method and the obtained results presented satisfactory recovery percentages (90–100.3%). 相似文献
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Development of a rapid screening technique for organochlorine pesticides using solvent microextraction (SME) and fast gas chromatography (GC) 总被引:1,自引:0,他引:1
A novel, fast screening method for organochlorine pesticides (OCPs) in water samples has been developed. Total analysis time was less than 9 min, allowing 11 samples to be screened per hour. The relatively new technique of solvent microextraction (SME) was used to extract and preconcentrate the pesticides into a single drop of hexane. The use of a conventional carbon dioxide cryotrap was investigated for introduction of the extract onto a micro-bore (0.1 mm) capillary column for fast GC analysis. A pulsed-discharge electron capture detector was used which yielded selective and sensitive measurement of the pesticide peaks. Fast GC conditions were optimised and tested with the previously developed SME procedure. Calibration curves yielded good linearity and concentrations down to 0.25 ng mL-1 were detectable with RSD values ranging from 12.0 to 28% and LOD for most OCPs at 0.25 ng mL-1. Spiked river water samples were tested and using the developed screen we were able to differentiate between spiked samples and samples containing no OCPs. 相似文献
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水中溶解氧的微量滴定 总被引:4,自引:0,他引:4
将微量滴定技术应用于常规的碘量法测定水中溶解氧。在实验中采用了WD-CO3型微量滴定装置,并使用自行设计制成的高精度微量移液管(移液的体积可准确至0.001mL),作为转移标准溶液及试样溶液的工具。对微量滴定及微量移液与常量滴定和常量移液作了对比试验,结果表明两者的分析结果完全吻合,微量滴定(其中包括微量移液)所得结果的精密度也在定量分析允许范围之内。由此,微量滴定技术应用于水中溶解氧的日常分析的可行性得到了验证。 相似文献