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沉淀分离富集-分光光度法测定海水中痕量活性磷酸盐 总被引:1,自引:0,他引:1
十六烷基三甲基溴化铵(cetyltrimethylammonium bromide,CTAB)可与磷钼蓝(phosphomolybdenum blue,PMB)生成水难溶的PMB-CTAB离子缔合物沉淀,从而分离富集水溶液中的PMB。该沉淀易溶于硫酸乙醇溶液,溶液在700 nm有强吸收,基于此建立了沉淀分离富集-分光光度法测定海水中痕量活性磷酸盐的新方法。对溶剂酸度、试剂用量、反应时间与温度等实验参数进行了优化选择,并考察了盐度对测定结果的影响。实验结果表明,PMB可被CTAB有效地定量沉淀;盐度在15~45范围内,对测定结果无影响。在优化的实验条件下,以盐度为35的人工海水为基底,做空白加P标实验,方法的线性范围为0.30~8.00μg/L,平均回收率为95.0%,方法检测限为0.10μg/L。对实际海水中痕量活性磷酸盐进行测定,相对标准偏差(RSD)为4.4%~7.1%,与广泛采用的MAGIC法比较,置信度为99%时结果无显著差异。新方法具有消耗试样体积少、测定速度快等优点。 相似文献
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设计了Cr6+流动注射自动在线检测系统,并对海水中Cr6+含量的检测条件进行了优化。本系统采用二苯碳酰二肼(DPC)比色原理,通过流动注射技术,结合光电检测、数字信号处理及自动化控制技术,实现了样品的全自动化分析。结果证明,本系统测定速度快(60样/时),线性范围宽(0.004~1.00 mg/L),检出限低(2.17μg/L),精密度高(RSD7.62%),实际水样的加标回收率为92.0%~100.8%。该系统具有简便快速、灵敏稳定、经济环保等优点,适用于海水、地表水、污水等各种水质中Cr6+的在线监测。 相似文献
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采用流动注射分析技术,在柠檬酸,碘存在的氨性介质中,以丁二酮肟为显色剂,应用光度自动分析方法,测定废水中微量镍,检出限为0.3mg·l~(-1);线性范围为0.3~10mg·l~(-1);相对标准偏差<1%。 相似文献
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流动注射催化光度分析法的研究进展 总被引:3,自引:0,他引:3
综述了近年来流动注射催化光度分析法的研究进展,包括环境水样中金属离子、阴离子、有机物等污染物的测定,展望了流动注射催化光度分析法未来的研究方向和发展前景。 相似文献
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工业废水中微量Cr^6+的流动注射光度分析 总被引:2,自引:0,他引:2
以离子交换法去除干扰离子,二苯碳酰二肼为显色剂,采用流动注射技术,以60个样/h的速度,分析电镀废水及其他废水中的C_r~(6+)。线性范围为0~5.0mg/l,检出限为0.09mg/l;对1.0mg/lC_r~(6+)标准溶液连续测定12次,其相对标准偏差为1.1%。 相似文献
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利用孔雀绿-磷钼杂多酸分光光度法与流动注射分析(FIA)联用,建立了一种简便、快速、直接的海水中磷酸盐的测定方法.在优化的实验条件下,当磷酸盐浓度在1~50 μg/L时呈现良好的线性,其线性方程为:y=1.2243x + 3.4529(R2 = 0.9995);检出限(3σ)为 0.29 μg/L;相对标准偏差(RSD)为 0.76 %(50 μg/L的磷酸盐添加于空白海水,n=8).利用本方法分析海水水样中的磷酸盐,回收率为91.9 % ~108.2 %.该方法不仅适用于海水中磷酸盐在实验室中的测定,而且满足监测站、监测船等的对磷酸盐的在线快速监测. 相似文献
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在Zn(CH3COO)2和NaOH溶液固定硫化物和硼砂缓冲液加强沉淀效果的基础上,提出用离心法将硫化物从溶液中分离出来,采用亚甲基蓝法测定水样中硫化物浓度的方法.该方法具有速度快,操作简单,准确度和回收率高的特点,用于浑浊海水中硫离子测定,收到满意效果. 相似文献
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A stopped-flow reversed flow injection method for the determination of free cyanide is proposed. Pyridine-barbituric acid mixture is injected in the flow system as reagent to form the colour species with cyanide. The flow is stopped when the reagent zone comes in the flow cell, where absorbance-time data are collected at 580nm wavelength. The linear range of the determination is 0.1 -10μg/ml CN-. The sampling rate is 60h-1 and the relative standard deviation is 1.6% (n=16) at 5.0 μg/ml CN-1 level. With satisfactory results, the proposed method was applied to the determination of free cyanide in wastewater without sample pretreatment. 相似文献
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Reversed flow injection spectrophotometric determination of low residuals of chlorine dioxide in water using chlorophenol red 总被引:1,自引:0,他引:1
A novel,simple,rapid,sensitive and highly selective flow injection procedure for the spectrophotometric determination of chlorine dioxide in the presence of othe chlorine species,viz,free chlorine,chlorite,chlorate and hypochlorite,is developed.The method is based on the discoloration reaction between chlorine dioxide and chlorophenol red and can overcome the shortcomings existed in direct spectrophotometric determination for chlorine dioxide owing to the serious interference of free and combined dhlorine.The procedure gave a linear calibration graph over the range0-0.71 mg/L of chlorine dioxide.With a detection limit of 0.024 mg/L and a sample throughput of 60 samples/h. 相似文献
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Poly(pheniothiazine) films were prepared on a porous carbon felt (CF) electrode surface by an electrooxidative polymerization of
three phenothiazine derivatives (i.e.,Tthionine (TN), Toluidine Blue (TB) and Methylene Blue (MB)) from 0.1 mol/L phosphate buffer
solution (pH 7.0). Among the three phenothiazies, the poly(TB) film-modified CF exhibited an excellent electrocatalytic activity for
the oxidation of nicotinamide adenine dinucleotide reduced form (NADH) at +0.2 V vs. Ag/AgCl. The poly(TB) film-modified CF
was successfully used as working electrode unit of highly sensitive amperometric flow-through detector for NADH. The peak currents
(peak heights) were almost unchanged, irrespective of a carrier flow rate ranging from 2.0 to 4.1 mL/min, resulting in the measurement
of NADH (ca. 30 samples/hr) at 4.1 mL/min. The peak current responses of NADH showed linear relationship over the concentration
range from 1 to 30 mol/L (sensitivity: 0.318 A/( mol/L); correlation coefficient: 0.997). The lower detection limit was found to be
0.3 mol/L (S/N = 3). 相似文献
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