共查询到20条相似文献,搜索用时 125 毫秒
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硒(Ⅳ)与DAN(2,3-二氨基萘)生成具有荧光特性的4,5-苯并苤硒脑,可用分子荧光光谱法测定,优化测定的实验条件,建立了快速准确测定大米中痕量硒的方法.结果表明,其最佳测定条件为:pH=2.0,反应温度为80℃,1.0×10-5 mol/L十六烷基溴化吡啶用作表面活性剂,环己烷萃取条件下,增敏效果明显,在0~0.0... 相似文献
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花旗参中铬含量的光度法测定 总被引:1,自引:0,他引:1
汤淳东 《广东微量元素科学》2004,11(10):54-56
研究了Cr (Ⅵ )催化H2 O2 氧化溴甲酚红 (BR)的反应。在HAc NaAc介质中 ,以溴化十六烷基三甲铵 (CTMAB)为增敏剂 ,测定波长为 5 86nm ,Cr (Ⅵ )浓度在 0~ 0 0 8μg/mL范围内与吸光度呈线性关系。方法灵敏 ,选择性好 ,用于花旗参中铬含量的测定 ,结果满意 相似文献
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增敏光度法测定化工污水中亚硝酸根 总被引:6,自引:0,他引:6
潘建 《理化检验(化学分册)》2001,37(2):92-93
化工企业排放的污水中常常会含有一定量的亚硝酸盐 ,它不仅会污染环境 ,而且严重威胁人类健康。因此 ,准确测定污水中亚硝酸盐含量是十分必要的。亚硝酸根的测定方法有色谱法、极谱法及比色法等。但应用胶束增敏作用进行测定的报道尚不多见 ,本试验在选择对硝基苯胺进行重氮化反应 ,2 -甲基 -8-羟基喹啉作为偶联试剂的情况下 ,借鉴广泛应用于金属阳离子测定的增敏作用 ,在形成的偶氮染料中加入阳离子表面活性剂溴化十六烷基三甲基铵(CTMAB) ,进行增敏测定。试验结果表明 ,生成的络合物在波长 590 nm处有最大吸收峰 ,表观摩尔吸光系数达 4.… 相似文献
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Masoud Shariati-Rad Mohsen Irandoust Farahnaz Niazi 《Journal of Analytical Chemistry》2016,71(7):660-666
A method for the determination of nitrite in soil and vegetable samples by UV-Vis spectroscopy was proposed. The kinetic UV-Vis data were collected during the reaction between nitrite and 4-amino-3-hydroxynaphthalene-1-sulfonic acid with concentration of 0.001 M and pH 1.6. Data were collected by standard addition method. Multivariate curve resolution-alternating least squares was employed to analyze data with non-negativity and three-way data structure constraints. The method can be used to solve matrix effect and unknown interferents in the determination of nitrite in complex samples. The proposed method was used to determine nitrite at low mg/L levels with satisfactory results in soil, lettuce, cabbage and cucumber samples. 相似文献
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T Aoki 《Biomedical chromatography : BMC》1990,4(3):128-130
A method for the determination of nitrite in water utilizing a membrane separation process and a chemiluminescence detector, with the addition of air-stripping and air-carrier, is proposed. The microporous poly(tetrafluoroethylene) tube was used as separator to transfer nitric oxide (reduced by iodine in acidic media) into a gas phase. Air-stripping was used to enhance the separation. Chemiluminescence signals produced from the reaction of nitric oxide with ozone were linearly proportional to the concentration of nitrite from 10 ppb (micrograms as N/L) to 5 ppm (mg N/L). The relative standard deviation (n = 5) was 0.7% at 0.1 ppm. The time elapse from starting the sample flow until the signal reached a stable level was 1.5 min. 相似文献
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流动注射催化光度法测定痕量亚硝酸根 总被引:6,自引:0,他引:6
采用流动注射技术与催化光度法相结合,研究了亚硝酸根催化溴酸钾氧化维多利亚绿G的高灵敏度褪色反应,用自制的微机化流动注射分析仪能准确控制时间,优化了实验条件,建立了测定痕量亚硝酸根的流动注射催化光度方法。分析速度每小时80次,克服了催化反应时间难以控制引起的方法精密度,准确不谪的弱点。亚硝酸根在0.0-0.3mg/L范围内,回归方程斜率为0.708;亚硝酸根在0.3-2.0mg/L范围内,回归方程斜率为0.339,方法用于直接测定水中的亚硝酸根获得满意结果。 相似文献
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A rapid, simple, and sensitive method for the determination of trace amounts of resorcinol, catechol, and hydroquinone in aqueous media has been proposed. The method is based on their reaction with nitrite. The excess nitrite is then determined by a kinetic method based on its reaction with Neutral Red. The reaction is monitored spectrophotometrically by measuring the decrease in the absorbance at 530 nm by a fixed time method. Resorcinol, catechol, and hydroquinone could be determined by the proposed method in the ranges of 0.1–2.0 mg/mL, 0.25–2.0 mg/mL and 0.1–3.0 mg/mL, respectively. The method was applied to the determination of resorcinol and catechol in pharmaceutical formulations with satisfactory results. 相似文献
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A new kinetic spectrophotometric method for the determination of hydrazine is described. The method is based on the inhibitory
effect of hydrazine on the reaction of neutral red with nitrite in acidic media and 28 °C. A product from the reaction of
neutral red with nitrite was used to monitor the reaction spectrophotometrically at 352 nm. Hydrazine can be determined in
the range 4.7×10−6∼3.1×10−5mol/L with a detection limit of 3.1×10−6mol/L. The method was applied to the determination of hydrazine in water samples.
Received July 23, 1999. Revision January 10, 2000. 相似文献