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采用氢化物发生原子荧光光谱法测定水中痕量锑。用盐酸和5%硫脲+5%抗坏血酸混合溶液处理样品,并以1.0%硼氢化钾和0.5%氢氧化钾为还原剂,在5%的盐酸介质中测定锑,锑的检出限(DL)为:0.028μg/L,相对标准偏差RSD(n=15)为3.1%,水样的加标回收率在94.3%~103.6%之间。本方法具有操作简便、快速、基体干扰少、灵敏度高和重现性好等优点,可用于水样中锑的测定。 相似文献
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《应用化工》2022,(11):2550-2554
将0. 5 g土壤进行消解,采用碘化钾-Cd(Ⅱ)-罗丹明B离子缔合分光光度法测定土壤中微量镉,最佳反应条件:加入2 m L浓度1 mol/L H2SO4,20%碘化钾-抗坏血酸溶液3 m L,显色40 min,在波长588 nm处测定离子缔合物吸光度。结果表明,Cd(Ⅱ)浓度在0. 25~2. 0μg/m L范围内符合郎伯-比尔定律。本方法测定结果相对标准偏差小于2%,方法检出限2. 1μg/kg,加标回收率98. 90%~100. 60%。实验表明,校园内土壤镉含量0. 035~0. 050 mg/kg范围内,几乎无金属镉污染。 相似文献
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用原子荧光光谱法测定水样中砷和硒.以10%盐酸和10%硫脲-10%抗坏血酸混合试剂处理样品,并以1.0%硼氢化钾和0.5%氢氧化钠为还原剂,在5%的盐酸介质中测定砷和硒.砷和硒的检出限分别为:0.20μg/L和0.13μg/L,砷的加标回收率为95%~108%,硒的加标回收率为90%~110%;本方法具有操作简便、快速、基体干扰少、灵敏度高等优点,可用于水样中砷和硒的联合测定. 相似文献
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五水偏硅酸钠广泛应用于洗涤产品中,是含磷洗涤助剂三聚磷酸钠的理想替代品.以粉煤灰基SiO2湿凝胶为原料,考察了SiO2湿凝胶用量、溶液结晶浓度、结晶温度和晶种用量对二氧化硅含量和总碱量的影响,结果表明:在100 mL 浓度为1 mol/L的氢氧化钠溶液中加入12~14 g的SiO2湿凝胶,浓缩至50 mL后降温至40~50 ℃范围内加入1.0%~1.5%晶种,均可获得符合HG/T 2568-2008标准要求的五水偏硅酸钠产品. 相似文献
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采用氢化物发生原子荧光光谱法,研究了联合测定水样中砷和硒的技术。用10%盐酸和1%硫脲-1%抗坏血酸混合试剂处理样品,并以2.0%硼氢化钾和0.5%氢氧化钠为还原剂,在5%的盐酸介质测定砷和硒。砷和硒的检出限分别为:As:0.05μg/L和Se:0.09 ug/L。本方法具有操作简便、快速、基本干扰少、灵敏度高等优点,可用于水样中砷和硒的联合测定。 相似文献
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研究了催化动力学分光光度法测定痕量铬。在硫酸溶液中,研究了痕量铬(Ⅵ)对溴酸钾氧化橙黄Ⅳ退色反应的催化效应及其动力学条件,建立了测定痕量铬(Ⅵ)的新方法。结果表明,最佳条件为:50 mmol/L硫酸溶液用量为3.0 mL,0.01%橙黄Ⅳ溶液用量为3.0 mL,5 mmol/L溴酸钾溶液用量为1.5 mL,在50℃水浴下反应6 m in,加入抗坏血酸溶液终止反应,并进行了干扰分析,方法的线性范围为0.2~1.0μg/L,检出限为1.09×10-6μg/L。该法用于水中痕量铬(Ⅵ)的测定,结果满意。 相似文献
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文章通过静态失重法和电化学法对缓蚀剂烯丙基硫脲在盐酸体系中对金属材料的缓蚀性能进行了研究。分别考察了不同缓蚀剂浓度、挂片温度及不同金属材料等情况下烯丙基硫脲的缓蚀性能。结果表明,烯丙基硫脲对Q235碳钢的缓蚀性能较好,失重法实验结果表明,在20℃下,0.5 mol/L盐酸溶液中加入100 ppm烯丙基硫脲对不锈钢的缓蚀率可达93%;0.5 mol/L盐酸溶液中加入50 ppm烯丙基硫脲对Q235碳钢的缓蚀率可达94%。电化学法实验结果则表明,当烯丙基硫脲浓度达到1000 ppm时,对不锈钢的缓蚀率达到97%,对Q235碳钢的缓蚀率可达98%。 相似文献
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《分离科学与技术》2012,47(9):1207-1228
Abstract Sodium borohydride can be used as an efficient agent for reducing gold and silver in acidic solutions of thiourea, thiocyanate, thiosulfate, acid chloride, and acid nitrate. The Au(I) ion is reduced to metallic gold in the form of very fine crystals, as indicated by XRD and SEM analysis. The reduction reaction is carried out at ambient temperature for a very short period of time (30 s). The reduction of Au(I) in such solutions can be performed for a wide range of gold concentrations (2 mg/L-2 g/L). Different parameters controlling the rate of the reaction and the efficiency of borohydride were studied, namely: acidity, stoichiometry, thiourea concentration, the presence of foreign ions, and temperature. Gold reduction by sodium borohydride is more favorable in the presence of Ag+ and/or Zn2+ ions, while the presence of Fe2+, Co2+, Ni2+, and Cu2+ ions decreases the efficiency of borohydride. The reduction reaction is selective for gold and silver over base metals in a solution mixture since the reaction is carried out in acidic medium. High recovery is obtained (>99%) and the product is pure. Thiourea does not undergo any degradation reaction during the course of reduction, and it can be recycled. The process appears promising for the gold industry due to its simplicity, speed, and low capital investment requirements. 相似文献
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Cotton cellulose was independently oxidized with potassium periodate, potassium dichromate-sulfuric acid, and potassium dichromate–oxalic acid, and the resulting oxidized celluloses were further modified by treatment with chlorous acid or sodium borohydride. The various modified celluloses so obtained were grafted with 2-methyl-5-vinylpyridine using a thiourea–dioxide–H2O2 redox system. It was found that the initiation characteristics of the cellulose samples vary widely with the oxidizing agent used. Further modification of the oxidized celluloses by treating them with chlorous acid enhances considerably their susceptibility toward grafting. The opposite holds true when these oxidized celluloses were modified by sodium borohydride treatment. Excluding thiourea dioxide from the polymerization system offsets grafting onto cotton cellulose while considerable grafting takes place on the various oxidized celluloses and their further modified samples. The work was also extended to study the factors which affect the graft uptake, homopolymer formation, and total conversion. In addition, the reactions involved in initiation of grafting were elucidated. 相似文献
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用毛细管电泳(CE)-紫外可见(UV-Vis)检测法测定鲫鱼中结晶紫残留量的新方法。样品中的结晶紫用硼氢化钾还原为其代谢产物隐色结晶紫;鲫鱼样品用乙腈提取,二氯甲烷萃取,浓缩净化后用毛细管电泳进样检测,外标法定量。结果表明:该方法能有效用于鲫鱼中结晶紫的分析检测。其最佳测定条件为:流动相,100 mmol/L磷酸-磷酸二氢钠缓冲溶液(pH4.0);紫外检测波长267 nm;分离电压为12 kV。结晶紫标准工作液浓度范围为1~32μg/mL时线性关系良好,相关系数为0.9942。方法检出限和定量检出限均为2.9μg/kg。空白样品结晶紫添加水平为5、10、20μg/mL时平均回收率分别为83.97%、109.55%和88.45%,相对标准偏差分别为3.22%、5.05%和2.09%。 相似文献
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在pH=4.0的乙酸-乙酸钠缓冲溶液中,微量的Hg(Ⅱ)对亚铁氰化钾与1,10邻-菲啰啉(1,10-0-phen)显色反应有催化作用,加入硫脲能提高其灵敏度,显色程度与Hg(Ⅱ)量在一定范围内呈线性相关,借此建立测定微量Hg(Ⅱ)的分光光度法。实验表明,有色溶液最大吸收波长为515 nm,摩尔吸光系数ε=3.72×106L/(mo.lcm),相关系数为r=0.999 1,催化程度与Hg(Ⅱ)浓度在(0.0~1.2)μg/25 mL范围内符合比耳定律,选择性好,利用该方法直接测定人工合成水样中汞的含量,以及河水、池塘水中微量汞的含量分析,结果满意。 相似文献
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采用反相高效液相色谱法测定化妆品中巯基乙酸的含量。色谱条件为:Kromasil C18(250 mm×4.6 mm,5μm)色谱柱,流动相为V(乙腈)∶V(0.01 mol/L KH2PO4溶液(磷酸调pH=2.5))=10∶90的混合溶液,流速1.0 mL/min,检测波长215 nm,柱温30℃,进样量20μL。结果表明,此条件下巯基乙酸在5.0~150.0μg/mL质量浓度范围内与峰面积线性良好,线性回归方程为Y=5 100X-13 400(r=0.999 8),平均回收率在98.4%~100.8%,RSD为0.09%~0.84%。 相似文献