溴酸钾氧化吡罗红G催化动力学光度法测定痕量NO2^—

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。     

溴酸钾氧化吡口罗红G催化动力学光度法测定痕量NO-2

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     

催化荧光光度法测定痕量亚硝酸根

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。     

溴酸钾氧化酸性品红催化光度法测定亚硝酸根

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。     

药物中亚硝酸根的流动注射催化光度法分析

以亚硝酸根催化溴酸钾在磷酸介质中氧化维多利亚天蓝Ｂ褪色为指示反应，建立了反相流动注射催化光度法测定痕量亚硝酸根的新方法。本法操作简单、快速，灵敏度高，测定亚酸根的线性范围为２￣８０μｇ／Ｌ，直接用于含硝酸内服药和针剂中亚硝酸根的测定，与α－萘胺比色法对照结果一致。     

催化光度法测定痕量亚硝酸根

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…     

催化动力学流动注射荧光光度法测定微量亚硝酸根

基于亚硝酸根离子在硫酸介质中催化溴酸钾氧化罗央明６Ｇ使其荧光强度降低的反应，建立了快速，灵敏，简便的催化动力学流动注射荧光光度法测定亚硝酸根的新方法。     

荧光动力学光度法同时测定硝酸根及亚硝酸根的研究

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。     

催化动力学光度法测定新鲜果蔬中痕量亚硝酸根

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     

溴酸钾氧化荧光素动力学荧光法测定痕量亚硝酸根

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。     

Ultrasensitive and selective determination of trace amounts of nitrite ion with a novel fluorescence probe mono[6-N(2-carboxy-phenyl)]-β-cyclodextrin

A novel fluorescence probe, mono[6-N(2-carboxy-phenyl)]-β-cyclodextrin (OACCD), has been developed for the determination of trace nitrite, In dilute HCl medium, the fluorescence intensity of the newly synthesized fluorescence probe OACCD was quenched in presence of trace nitrite at room temperature. Based on this, a simple, sensitive, and selective method for rapid determination of nitrite was described. Furthermore, common ions do not interfere the determination of trace amounts of nitrite. The fluorescence quenching intensity was linear over a nitrite concentration of 0.02-1.7 μmol l⁻¹ with a detection limit of 0.2 nmol l⁻¹ (S/N = 3). The method was applied to the determination of nitrite in different water samples, soil samples, and food samples with satisfactory results.     

流动注射催化光度法测定痕量亚硝酸根

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。     

非平衡流动注射光度法测定微量亚硝酸根的研究

采用流动注射分析技术,研究了在酸性介质中碱性品红与亚硝酸根的反应,用自制的微机化流动注射分析仪准确控制反应时间,利用非平衡法原理,优化了实验条件,建立了测定微量亚硝酸根的新方法。线性范围为０．０～５．０ｍｇ／Ｌ,分析速度达每小时测定３６次。应用该法直接测定煤矿塌陷湖水、鱼塘水、电厂废水和地下水中的亚硝酸根获得满意结果。     

Development of a new fluorescent probe: 1,3,5,7-tetramethyl-8-(4'-aminophenyl)-4,4-difluoro-4-bora-3a,4a-diaza-s-indacence for the determination of trace nitrite

A new fluorescent probe, 1,3,5,7-tetramethyl-8-(4'-aminophenyl)-4,4-difluoro-4-bora-3a,4a-diaza-s-indacence (TMABODIPY) has been developed for the determination of trace nitrite in terms of the reaction of nitrite with TMABODIPY first in acidic solution and then in alkaline solution to form diazotate, a stable and highly fluorescent reagent. The method offered the advantage of specificity, sensitivity and simplicity. The linear calibration range for nitrite was 8-300 nmol l-1s with a 3 sigma detection limit of 0.65 nmol l-1. The proposed method has been applied to monitor the trace nitrite in drinking water and vegetable without extraction.     

催化光度法测定痕量亚硝酸根

基于稀磷酸介质中亚硝酸根催化溴酸钾氧化靛蓝的褪色反应,建立测定痕量亚硝酸根的方法。方法检出限为1.36×10-6g.L-1,线性范围为0.012~0.08mg.L-1,回收率为98.0%~100.8%。方法已用于水中亚硝酸根的测定,结果满意。     

A kinetic method for the determination of nitrite by its catalytic effect on the oxidation of chlorpromazine with nitric acid.

A catalytic spectrophotometric method for the determination of trace amounts of nitrite is proposed. In acidic solution, chlorpromazine (CP) is oxidized by nitric acid to form a red compound, which is further oxidized to a colorless compound. The reaction is accelerated by trace amounts of nitrite and can be followed by measuring the absorbance at 525 nm: nitrite ion is regenerated and multiplied by nitric acid. The absorbance of the reaction increased with an increase in the reaction time, reached a maximum and decreased rapidly. Since the time required for the absorbance to reach the maximum decreased with increasing nitrite concentration, this value was used as the measured parameter for the nitrite determination. Under the optimum experimental conditions (2.3 M nitric acid, 1.2 x 10(-5) M CP, 40 degrees C), nitrite can be determined in the range 0-100 microg l(-1). The relative standard deviations (n = 6) are 4.7 and 1.8% for 40 and 100 microg l(-1) nitrite, respectively. The detection limit of this method (3sigma) is 1.2 microg l(-1). This method was successfully applied to a determination of nitrite in natural water samples.     

浊点萃取光度法测定水样中亚硝酸根

A new method for the determination of trace nitrite by spectrophotometric after cloud point extraction was proposed.The effects of experimental conditions such as acidity,concentration of chromogenic reagent and surfactant,equilibration temperature and time on cloud point extraction were discussed.Under the optimum conditions,a good linear relationship was obtained in the range of 4.0～200 μg/L of the nitrite(r=0.9998),the detection limits of 0.43 μg/L.The recoveries fell in the range from 97.7% to 102.4% an...     

Kinetic spectrophotometric determination of low levels of nitrite by catalytic reaction between pyrogallol red and bromate

A kinetic spectrophotometric method for the determination of trace nitrite (0.003-1.000 microg/ml) based on its catalytic effect on the reaction between potassium bromate and pyrogallol red in acidic media is described. The reaction is monitored spectrophotometrically by measuring the decreasing colour of pyrogallol red at 467 nm by the fixed-time method. At a given time of 3.0 min at 30 degrees, the detection limit is 0.001 microg/ml and the relative standard deviation for 0.010 microg/ml nitrite is 1.8% (n = 8). The method is free from most interferences, especially from large amounts of nitrate and ammonium. The procedure was successfully applied to the determination of trace nitrite in natural water without preconcentration.