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1.
溴酸钾氧化亮绿SF催化光度法测定痕量亚硝酸根   总被引:30,自引:3,他引:27  
鲍所言  王彤立 《分析化学》1995,23(2):191-193
本文基于亚硝酸根对溴酸钾氧化亮绿SF而使其褪色所起的催化作用,建立了高灵敏度催化吸光光度法测定痕量亚硝酸根的新方法,测定范围为0.05-20ng/ml,用于不同水样中亚硝酸根的测定,获得了满意结果。  相似文献   

2.
溴酸钾氧化吡罗红G催化动力学光度法测定痕量NO2^—   总被引:3,自引:0,他引:3  
研究了在磷酸介质中亚硝酸根催化溴酸钾氧化吡罗红G而使褪色,建立了催化动力学光度法测定痕量亚硝酸根的新方法,测定范围为0.2-20μg/mL,检出限为0.2ng/ml,用于食品和水样中的亚硝酸根测定获得满意结果。  相似文献   

3.
研究了在磷酸介质中亚硝酸根催化溴酸钾氧化吡口罗红G而使其褪色,建立了催化动力学光度法测定痕量亚硝酸根的新方法,测定范围为0.2~20μg/mL,检出限为0.2ng/mL,用于食品和水样中的亚硝酸根测定获得满意结果  相似文献   

4.
催化荧光光度法测定痕量亚硝酸根   总被引:5,自引:0,他引:5  
亚硝酸根广泛存在于环境、水体、食品等物质中,它可与胺类及酰胺类化合物反应生成致癌物亚硝胺,因此,它是水质、环境、食品等检测的重要项目之一。催化动力学光度法测定亚硝酸根已有不少报道,而催化荧光法测定亚硝酸根的报道不多。吡啰红B是一种生物染色剂,在水溶液中发射红色荧光。试验发现,稀磷酸介质中,溴酸钾氧化吡哕比B使荧光猝灭,亚硝酸根对此氧化还原褪色反应具有灵敏催化作用,据此建立了测定亚硝酸根的催化荧光光度法。本法灵敏度较高,选择性好,简便快速,用于水及蔬菜中痕量亚硝酸根的测定,结果满意。  相似文献   

5.
表面活性剂增敏催化光度法测定痕量亚硝酸根   总被引:12,自引:0,他引:12  
张爱梅  王术皓  崔慧 《分析化学》2001,29(2):202-204
基于稀磷酸介质中,溴化十六烷基吡啶对亚硝酸根催化溴酸钾氧化吡罗红B褪色反应的增敏作用,建立了测定亚硝酸根的表面活性剂增敏催化动力学光度法。加入溴化十六烷基吡啶,灵敏度增大2.2倍。测量亚硝酸根的线性范围为0.005-0.15 mg/L,检出限为0.004/L。用于水及蔬菜中痕量亚硝酸根的测定,结果满意。  相似文献   

6.
溴酸钾氧化酸性品红催化光度法测定亚硝酸根   总被引:9,自引:2,他引:7  
研究了在强酸介质中亚硝酸根催化溴钾氧化酸性品红的褪色反应及其动力学条件,建立了高灵敏测定痕量亚硝酸根的新催化光度法。方法灵敏度为3.7×10^-11g/cm^2亚硝酸态氮,线性范围为0.06-0.42μg/10mL,用于测定唾液及硝钾中亚硝酸根。  相似文献   

7.
催化动力学光度法测定新鲜果蔬中痕量亚硝酸根   总被引:3,自引:1,他引:2  
基于在稀磷酸介质中亚硝酸根对溴酸钾氧化百里酚蓝褪色反应的催化效应 ,建立了一种测定痕量亚硝酸根的催化光度法。该方法测定亚硝酸根的线性范围为 0~ 6 .5 μg/ 2 5ml,灵敏度为 0 .6 7ng·ml- 1。用于新鲜果蔬样品中痕量亚硝酸根的测定 ,结果满意  相似文献   

8.
催化光度法测定痕量亚硝酸根   总被引:17,自引:0,他引:17  
张克忠  冯尚彩 《分析化学》1998,26(4):494-494
1引言近年来,有关催化光度法测定亚硝酸根的方法已有若干报道。笔者在前人进行荧光测定的基础上,研究了在稀磷酸介质中,亚硝酸根对溴酸钾氧化中性红的强催化作用,提出了以溴酸钾为氧化剂,中性红为还原剂测定亚硝酸根的催化光度法,结果具有很高的灵敏度和较好的选择性。用于地面水及地下水中NO-2的测定,结果满意。2实验部分2.1仪器与试剂753WB紫外可见分光光度计(上海光学仪器厂);电热恒温水浴锅。亚硝酸根标准溶液:由亚硝酸钠配成1.00g/L亚硝酸根储备液;本溶液贮存于棕色瓶中,每升加入2mL三氯甲烷和两…  相似文献   

9.
溴酸钾氧化荧光素动力学荧光法测定痕量亚硝酸根   总被引:35,自引:8,他引:27  
基于稀硫酸介质中,亚硝酸根催化溴酸钾氧化荧光素,建立了动力学荧光法测定痕量亚硝酸根的新方法。本方法具有高灵敏度和高选择性,测定亚硝酸根的线性范围为2~80ng/ml,可用于直接测定水样中亚硝酸根。  相似文献   

10.
亚硝酸根的催化光度法测定   总被引:11,自引:0,他引:11  
本法基于甲酸介质中,亚硝酸根对溴酸钾氧化甲基橙褪色的催化效应,用正交法确定最佳测定条件。本法测定亚硝酸根的线性范围为0~0.20μg/mL灵敏度为2.83×10-10g/mL。用于测定水样中的亚硝酸根,结果良好。  相似文献   

11.
Montes R  Laserna JJ 《Talanta》1987,34(12):1021-1026
A method for the kinetic determination of submicrogram amounts of nitrite has been developed, based on its acceleration of the rate of bromate oxidation of pyridine-2-aldehyde 2-pyridylhydrazone in acidic medium. The reaction is monitored spectrophotometrically at 372 nm. A comparative study with hydrochloric acid and perchloric acid media shows that the analytical parameters are affected by the type of acid used. Within-day precision, based on ten replicate determinations, was better than 0.011 μ/ml, which corresponds to 2.2-1.5% relative standard deviation at the concentrations examined. Application of this method in the determination of nitrite in water has been discussed. The recovery of nitrite from drinking waters ranges from 90 to 117% and the average relative standard deviation for nitrite determinations in polluted river water is 3.2%. Large amounts of nitrate and ammonium ions do not interfere. However, there is interference by Cu2+, Pd2+ and electroactive substances. Major advantages for the method are simplicity, absence of a reagent blank, and the wide determination range.  相似文献   

12.
荧光动力学光度法同时测定硝酸根及亚硝酸根的研究   总被引:18,自引:0,他引:18  
张贵球  张海清 《分析化学》1994,22(10):1006-1008
基于亚硝根对溴酸钾氧化罗丹明6G的催化及锌粉使硝酸根还原为亚硝酸根的原理,建立了同时测定亚硝酸根和硝酸根的荧光动力学法,用于饮用水、质控水样、饮料中硝酸根及亚硝酸根的测定,测定下限分别为0.074ngNO2^-/ml和0.25ngNO3^-/ml。  相似文献   

13.
A controlled-potential coulometric iodometric method previously developed for the accurate determination of small amounts of nitrite has been extended for the determination of nitrate after its reduction on a coppered cadmium reductor. The conditions for quantitative reduction have been investigated with respect to type of reductor and pH. Nitrate-nitrogen in the range 0.01-100 mug ml may be determined with high accuracy in less than 10 min, including the reduction step. The method has been applied with good results to a large variety of samples such as meat products, juices and waste waters.  相似文献   

14.
Summary The effect of four surfactants on the determination of nitrite and nitrate has been examined. The method which has been tested for nitrite is based on the formation of an azodye. The results show that cationic and non-ionic surfactants do not interfere with the determination of nitrite while anionic surfactants cause significant interferences, which could be eliminated by treating the water samples with a cationic surfactant.Two methods have been tested for the determination of nitrate in the presence of surfactants. One method is based on the nitration of salicyclic acid, while the other is based on the reduction of nitrate to nitrite. Results for the first method show that the non-ionic surfactant Triton-X causes significant interferences. Cationic and anionic surfactants do not interfere, when their concentration is relatively low. For higher concentrations an increasing interference is observed. Results for the second method show effects similar to those obtained for nitrite.
Wirkung oberflächenaktiver Substanzen auf die Bestimmung von Nitrit und Nitrat in Wasserproben
  相似文献   

15.
Y Michigami  Y Yamamoto  K Ueda 《The Analyst》1989,114(10):1201-1205
An ion chromatographic method has been developed for the determination of trace amounts of nitrite, sulphate, bromide and nitrate in human serum, using an ODS column dynamically coated with cetylpyridinium chloride. The anions studied were eluted with 1 mM citrate - 2.5% methanol (pH 6.5) as the mobile phase and detected by an ultraviolet detector. The interfering proteins in human serum were removed by an initial filtration through an ultrafilter-paper. The many inorganic and organic anions commonly found in serum had little effect on the determination of the four anions. Recoveries of nitrite, sulphate, bromide and nitrate in serum were 107-110, 94-106, 106-110 and 92-100%, respectively. The proposed method was also applied to human saliva and urine.  相似文献   

16.
Monser L  Sadok S  Greenway GM  Shah I  Uglow RF 《Talanta》2002,57(3):511-518
A direct spectrophotometric flow injection method for the simultaneous determination of nitrite and nitrate has been developed. The method is based on the oxidation of a phosphomolybdenum blue complex by the addition of nitrite and the decrease in absorbance of the blue complex is monitored at 820 nm. The injected sample is split into two segments. One of the streams was directly reacted with the above reagent and detected as nitrite. The other stream was passed through a copperised cadmium reductor column where reduction of nitrate to nitrite occurs, and the sample was then mixed with the reagent and passed through the cell of the spectrophotometer to be detected as nitrite plus nitrate. The conditions for the flow injection manifold parameters were optimised by experimental design and the concentration of nitrite and nitrate was determined in the linear range from 0.05 to 1.15 mug ml(-1) nitrite and 0.06 to 1.6 mug ml(-1) nitrate with a detection limit of 0.01 mug ml(-1) for nitrite and 0.025 mug ml(-1) for nitrate. The method is suitable for the simultaneous determination of nitrite and nitrate in fish and water samples with a sampling rate of 25+/-2 sample per hour.  相似文献   

17.
Two flow-injection manifolds have been investigated for the determination of nitrate. These manifolds are based on the reduction of nitrate to nitrite and determination of nitrite by gas-phase molecular absorption spectrophotometry. Nitrate sample solution (300 microL) which is injected to the flow line, is reduced to nitrite by reaction with hydrazine or passage through the on-line copperized cadmium (Cd-Cu) reduction column. The nitrite produced reacts with a stream of hydrochloric acid and the evolved gases are purged into the stream of O2 carrier gas. The gaseous phase is separated from the liquid phase using a gas-liquid separator and then swept into a flow-through cell which has been positioned in the cell compartment of an UV-visible spectrophotometer. The absorbance of the gaseous phase is measured at 204.7 nm. A linear relationship was obtained between the intensity of absorption signals and concentration of nitrate when Cd-Cu reduction method was used, but a logarithmic relationship was obtained when the hydrazine reduction method was used. By use of the Cd-Cu reduction method, up to 330 microg of nitrate was determined. The limit of detection was 2.97 microg nitrate and the relative standard deviations for the determination of 12.0, 30.0 and 150 microg nitrate were 3.32, 3.87 and 3.6%, respectively. Maximum sampling rate was approximately 30 samples per hour. The Cd-Cu reduction method was applied to the determination of nitrate and the simultaneous determination of nitrate and nitrite in meat products, vegetables, urine, and a water sample.  相似文献   

18.
《Analytical letters》2012,45(11):761-775
Abstract

A sensitive fluorimetric method has been developed for the determination of nitrate based on the reduction of nitrate to nitrite with hydrazine sulfate and the subsequent determination of the nitrite formed with 2, 3-diaminonaphthalene. Solvent effect on fluorescence intensity, optimum reaction conditions, and sensitivity of the method are discussed.  相似文献   

19.
Szekely E 《Talanta》1967,14(8):941-950
p-Diaminodiphenylsulphone is used in a new spectrophotometric method for the determination of nitrate. Factors affecting the colour development are given. The useful range for a 1-cm cell is 30-300 mg l . In this range the coloured solutions are stable and obey Beer's law. The method is rapid and precise and is applicable to routine analysis of samples containing macro amounts of nitrates. For determination of micro amounts of nitrate the reagent is modified by addition of diphenylamine. The limit of determination is then 0.25 mg l at 15 degrees . This method can be considered specific for nitrate and is applicable in the presence of nitrite.  相似文献   

20.
基于NO_2~-、NO_3~-和Fe(Ⅲ)对甲基橙光化学褪色反应的催化作用,利用自制流通式光化学反应器,建立了流动注射光化学反应同时测定NO_2~-和NO_3~-以及测定Fe(Ⅲ)的新方法。测定NO_2~-和NO_3~-的线性范围都是0.1~3.2mg/L,每小时可测30~40个样品,测定Fe(Ⅲ)的线性范围为0.06~1.2mg/L,进样频率为60~80次/h。应用于蔬菜中NO_2~-、NO_3~-的测定和茶叶中铁的测定,结果满意。  相似文献   

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