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流动注射分光光度法测定亚硝酸根氮 总被引:1,自引:0,他引:1
使用北京吉天仪器有限公司水质分析仪样机建立了测定水中痕量亚硝酸根氮的流动注射光度方法,以先进的光纤光谱仪CCD作为检测器,亚硝酸盐与对氨基苯磺酰胺重氮化,再与盐酸N-(1-萘基)乙二胺偶合,形成玫瑰红色的偶氮染料,用分光光度法测定,其最大吸收峰在540nm处;最佳的显色管路长度1.5m;最佳的对氨基苯磺酰胺质量浓度为1.0g/L;最佳的N-(1-萘基)乙二胺质量浓度为60g/L,亚硝酸根氮的线性范围为0.002~1.0mg/L,检出限0.37μg/L,RSD0.2%,实际样品的加标回收率均在96.5%~101.2%之间,测定频率60样/h。 相似文献
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近年来,由于含铁水处理剂的广泛应用,水体中铁含量逐渐增高.含铁量高的水在管道内易生长铁细菌,增加水的浑浊度,使水产生特殊的色、嗅、味,易污染衣物、器皿,影响某些工业产品的质量.因此,研究准确快速测定水中铁的分析方法具有重要意义. 相似文献
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流动注射光度法测定药物中的盐酸氯丙嗪 总被引:1,自引:0,他引:1
在pH 4.04的HAc-NaAc缓冲液中, 刚果红与盐酸氯丙嗪在室温下迅速结合生成缔合物, 且缔合物在480 nm处有最大吸收. 基于此建立了流动注射光度法测定药物中盐酸氯丙嗪的含量. 方法线性范围为0.25~50.0 μg/mL, 检出限为0.082 μg/mL, 测定频率达80次/h. 相似文献
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基于亚硫酸盐在碱性条件下与碱性品红的褪色反应,建立了流动注射光度分析测定食品中亚硫酸盐的新方法.在38样/h采样频率下检出限为0.016μg/mL,SO32-质量浓度在0.04~1.5 μg/mL范围符合朗伯比耳定律,测定1.2μg/mL SO32- 11次,相对标准偏差为0.41%.该法可用于食品中亚硫酸盐的测定. 相似文献
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Determination of ethanol in liquor by near-infrared spectrophotometry with flow injection 总被引:2,自引:0,他引:2
A simple procedure for the determination of ethanol in a liquor by near-infrared (NIR) spectrophotometry with flow injection (FI) is proposed. A liquor sample is equilibrated off-line with dried chloroform to extract ethanol into the organic phase. The extract is injected into a carrier stream of dried chloroform passing through a home-made flow through cell (1 mm path length) sitting in a NIR spectrophotometer for continuous monitoring of absorbance at 2305 or 2636 nm. The ethanol content can be evaluated from a calibration established by a plot of change in absorbance versus concentration of ethanol standard solutions. Optimization of the system will be discussed. A calibration is linear in the range of 20–50% (v/v) ethanol. A throughput of 240 injections h−1 can be obtained. The procedure is validated by comparing the results with an analysis using gas chromatography. 相似文献
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Xin-feng Xiao Yu-ying Deng 《International journal of environmental analytical chemistry》2013,93(12):1095-1105
ABSTRACTThe flow injection catalytic spectrophotometry is proposed for the determination of nitrite based on the catalytic effect on the redox reaction between methylene blue and potassium bromate in acidic medium. The reaction is monitored spectrophotometrically by measuring the decrease in the absorbance of methylene blue at the maximum absorption wavelength of 664 nm. The method is characterised by low solvent consumption and easy automatic continuous analysis. It has higher sensitivity and lower detection limit. Experimental analysis conditions of the flow injection-catalytic photometry are optimised, and the best analysis conditions are: the concentration of the potassium bromate is 0.068 mol L?1; the concentration of the phosphoric acid in oxidation liquid is 0.045 mol L?1; the concentration of the methylene blue in colour-substrate solution is 2.4 mg L?1, the volume of sample ring is 200 μL; the reaction coil is around 7 m in length; the inject time is 50 s and analysis time is 70 s. Under the optimal conditions, the linear range is from 10 to 500 μg L?1 and the detection limit is 1 μg L?1. The nitrate standard solution is continuously determined with a mass concentration of 300 μg L?1. The RSD is determined to be 1.41% (n = 10). The nitrite in water samples, which were from the Half Acre pond, the Ink River and the Small West lake in a campus, was determined respectively by this method. A satisfactory standard addition recovery of 96.7%–103.9% was obtained. 相似文献
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Shizuko Hirata Bhavaniamma Vijayalekshmi Amma Sathrugnan Karthikeyan Kei Toda 《Analytical sciences》2003,19(12):1687-1689
A simple, rapid, low cost and accurate determination using flow injection spectrophotometry with a home made flow cell detector, in combination with green LED and photodiode, had been developed for nitrite based on the Griess-Saltzman reaction, measuring the absorbance at 525 nm. The proposed system is able to monitor nitrite in freshwater samples at a throughput of 60 samples per hour with a relative standard deviation (%RSD) of less than 2.4% and a detection limit of <7 microg dm(-3). The calibration graph was linear between 0.010 - 1.0 mg dm(-3). 相似文献
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A spectrophotometric method for the determination of formaldehyde in foodstuffs was described by using phloroglucinol as the chromogenic agent. The reaction between formaldehyde and phloroglucinol could occur rapidly at room temperature under mild conditions. The spectrophotometric measurements were conducted at 474nm of an unstable intermediate orange product of the reaction, which greatly increased the sample throughput. Flow injection technique was used to control the merging and reaction timing of the reagents and sample. A detection limit (3sigma) of 0.023microg ml(-1) was achieved. The relative standard deviation was 0.29% for the determination of 7microg ml(-1) formaldehyde (n=11). The proposed method was applied to the analyses of formaldehyde in several preserved foodstuffs and the results were in good agreement with those obtained by a standard method. 相似文献
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A new flow injection spectrophotometric method is described for the simultaneous determination of silicate and phosphate. Effects on the sensitivity of the method of the wavelength, temperature, length of reaction coils, pump rates, acidity, sampling volume, concentration of the chromogenic reagent, etc. were also investigated. The optimum conditions were ascertained.The principle of the method is that total concentration of silicate plus phosphate is determined when a injected sample plug is passing through the first flow cell and then the concentration of silicate is serially) determined at a second flow cell of the same detector after continuously masking the yellow molybdophosphate in the sample zone. Finally, the concentration of phosphate is obtained by difference.Silicate and phosphate are determined in boiler water at power plants; 60-120 samples h−1 be analyzed. Determination ranges are 0.05-22 mg l−1 for silicate and 0.1-24 mg l−1 for phosphate. Relative standard deviations for metasilicate and orthophosphate were ≤1.2 and 1.3%, respectively. Recovery ranges of silicate and phosphate in the samples are 98-103%. 相似文献
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This paper describes the application of the well-known Molybdenum Blue method for selective determination of arsenite in a flow injection system. Selectivity is achieved by on-line separation of the main interferents phosphate, arsenate and silicate using a strong anion-exchange microcolumn located in the aspiration line of injection valve. Arsenite passing through the microcolumn unretained is determined using Molybdenum Blue method following in-line oxidation to arsenate by permanganate. A thorough investigation of optimal experimental conditions for both, the separation of interferents and sensitive detection of arsenite is presented. The method developed permits arsenite to be determined in the concentration range 5-500 microg/l with high precision and reliability. A sample throughput of 20 hr(-1) is achieved. Phosphate, arsenate and silicate do not interfere at concentration levels significantly higher than that of arsenite. The application to real water samples reveals excellent recovery of spiked samples and the absence of matrix interferences. 相似文献
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Dimethyl sulfoxide (DMSO), carrying a highly polarized S = O bond as the H-bond acceptor, possesses an extraordinarily high capacity to compete for H-bond formation. This strongly H-bonding character renders DMSO with a strong ability to interfere with or even disrupt self-assembled structures mediated predominantly by intermolecular H-bonds. While this might be quite disturbing in many applications, in this study, we show that oil gelation actually could benefit significantly from DMSO’s such a strong H-bond-breaking ability. More specifically, we found that use of a minute but optimized amount of DMSO, assisted further by polar acetonitrile of a suitable amount, weakens the H-bonds in the gelling network formed by organogelators to a just right extent so as to allow for a faster disassembly-reassembly of fibers in the wetted powder gelator in oil and subsequent occurrence of rapid room-temperature gelation of both light and heavy crude oils of widely ranging viscosities within 6–25 mins at gelator loadings of ≤12% w/v. 相似文献
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Fourth-derivative absorption spectra were used to determine trace amounts of manganese in nickel salts. Optimum conditions for the oxidation of microgram amounts of Mn(II) to MnO(-)(4) in the presence of large amounts of nickel were established. Fourth-derivative spectra provided good sensitivity and selectivity for this determination. Attention has been paid to the effect of instrumental parameters on the results obtained. Limitations of the peak-to-trough and zero-crossing measurement techniques have been examined. Manganese (1 x 10(-3)-2 x 10(-5)%) in nickel salts (nitrate, sulphate and chloride) and in nickel powder was determined with good precision and accuracy. 相似文献
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Palladium is shown to be deposited underpotentially on gold electrodes in 1 M H2OSO4. The deposit forms an alloy according to a t1/2 law. The rate of alloy formation is strongly dependent on the potential. The diffusion coefficient is about 10?16 cm2 s?1. This value is discussed in comparison with earlier measurements on gold-palladium alloys at higher temperatures. 相似文献