反相流动注射-分光光度法测定水中痕量余氯的研究

研究并建立了测定水中痕量总余氯和游离余氯的Ｎ,Ｎ－二乙基－１,４－苯二胺（ＤＰＤ）反相流动注射分光光度法。将ＤＰＤ溶液和ＨＰＯ４＾２－－Ｈ２ＰＯ４＾－缓冲溶液（ｐＨ６．７）的混合液注入试样载流中,再与ＫＩ溶液或硫代乙酰胺溶液流混合,在５１０ｎｍ处对反应形成的红色半醌式化合物进行分光光度测定。     

流动注射在线分离分光光度法测定痕量总酚

在盐酸介质中，利用对氨基苯磺酸-亚硝酸钠-苯酚的重氮化-偶合反应，联用流动注射溶液处理技术，对工业废水在线自动化分离和预浓集处理，实现了实际样品中酚的在线分离富集及测定。利用单纯形优化法选择了最佳实验条件。方法的线性范围为0．1—20mg/L；进样频率为36／h；检出限为O．02mg／L。该方法用于工业废水中痕量酚的测定，其测定结果与4-氨基安替比林比色法对照，经统计学处理，没有显著性差异。     

流动注射分光光度法测定亚硝酸盐仪器的研制

设计了亚硝酸盐流动注射自动在线监测仪,并研究了仪器的最佳测试条件．先将亚硝酸盐与对氨基苯磺酰胺重氮化,再与N-（1-萘基）乙二胺盐酸盐偶合,形成玫瑰红色的偶氮染料,在光程为60mm、光源为540nm的流通池内检测．实验发现最佳磺胺质量浓度为40g/L,N-（1-萘基）乙二胺盐酸盐质量浓度为0．6g／L,最佳采样量为300μL,反应管最佳长度为3m．亚硝酸盐的线性范围为10～1200μg／L,检出限为4．78μg／L,Rsd为1．02％（n=11）,实际水样的加标回收率在96．5％～106．2％之内．本仪器消耗试剂量少、测定快速、灵敏、抗干扰能力强,适宜于现场即时监测．     

反相流动注射催化光度法测定亚硝酸根

采用反相流动注射技术与催化光度法相结合 ,研究了亚硝酸根在盐酸介质中催化溴酸钾氧化维多利亚蓝的灵敏褪色反应 ,用自制的微机化流动注射分析仪能准确控制时间 ,优化了试验条件 ,建立了测定痕量亚硝酸根的反相流动注射催化光度新方法。分析速度 36次·h- 1,克服了催化反应时间难以控制引起的方法精密度 ,准确度不高的弱点。亚硝酸根在 0 .0 0～ 2 .0 0mg·L- 1范围内 ,回归方程斜率为 0 .2 6 2。方法直接测定水中的亚硝酸根获得满意结果     

流动注射-分光光度法测定铝合金中的磷

1　引　　言流动注射分析 (ＦＩＡ)用于实际样品中磷的测定已有许多文献报道 ,而有关合金中磷的测定很少见。杂多酸吸收光度法测定磷影响因素很多 ,用于合金分析比较困难。为此我们以栓塞铝合金为对象 ,对测定条件及干扰情况进行了详细研究。本方法可以有效地消除金属离子干扰 ,进样频率 6 0次 ｈ,检测限为 0 .0 5ｍｇ Ｌ ,实际样品的测定结果令人满意 ,适合于大批量铝合金样品的测定。2　实验部分2 1　仪器与试剂　ＴＲＢ型蠕动泵 (东北电力学院仪器仪表厂 ) ,配以适当规格的ｔｙｇｏｎ泵管 ;72 1分光光度计 (四川分析仪器仪表厂 ) ,配以…     

流动注射—双显色剂双波长分光光度法同时测定铝与铁

本文将流动注射与双波长双光束分光光度计联用，选择铬天菁Ｓ和亚硝基Ｒ盐双显色剂使ＡＩ（Ⅲ）和Ｆｅ（Ⅱ）同时显色。建立了同时测定铝、铁的流动注射－双波长等吸收法。方法用于岩矿样品中铝、铁的测定，结果满意。     

流动注射-分光光度法间接测定微量苯胺

1　引　　言苯胺有致癌作用 ,是环境污染控制的重要指标之一。目前标准方法采用重氮化偶合反应分光光度法测定 ,也有用气相色谱法测定或者用极谱法测定。本文研究了在ＫＢｒ存在下 ,稀盐酸介质中苯胺与亚硝酸盐迅速进行重氮化反应 ,根据剩余亚硝酸盐与碘化钾反应生成单质碘 ,遇淀粉变蓝的高灵敏反应原理 ,采用流动注射分析法进行了实验条件的优化 ,建立了流动注射分光光度法间接测定微量苯胺的新方法 ,线性范围 0 .0～ 1.0× 10 - 3ｍｏｌ Ｌ ,测量速度 30次 ｈ ,用于棉纺厂废水、印染厂废水和河水中微量苯胺的测定 ,获得了满意结果 ,回收率…     

催化流动注射光度法测定痕量银的研究

酸性介质中,当有活化剂邻菲咯啉(Phen)存在时,S_2O_8~(2-)氧化反应在Ag(I)的催化作用下大大增强,可使反应速度提高2～3个数量级。根据这一事实,本文制定了测定痕量银的催化流动注射光度法。方法简单、选择性较好,分析速度达到70个样品/小时,在室温条件下,检出限达到5ng/ml,变异系数为5.78%(n=6)。     

流动注射分光光度法测定水体总磷

提出了一种单通道紫外消解流动注射比色分析法，能快速测定水样中总磷。实验采用了微量恒流混合泵、新型的细长型高灵敏度流通池及紫外消解器、液流分配阀、恒流瓶等FIA装置，并使用工业编程控制器和智能触摸屏进行控制和计算，使操作更为方便。此法分析时间短，测量范围宽，精度高，适合于各种水体的测定。     

流动注射分光光度法测定微量硫氰酸根

基于３，５－Ｂｒ２－ＰＡＤＡＰ硫氰酸根分别与重铬酸根，铈（ＩＶ）在硫酸介质中反应成不稳定的蓝色产物，建立了两种测定微量硫氰酸根的流动注射分光光度新方法，在前一方法中，硫氰酸根含量在０．８０～７．２０ｍｇ／Ｌ范围内可定量测定，检出限为０．２７ｍｇ／Ｌ在后一方法中，硫氰酸根含量在０．８０～６．４０ｍｇ／Ｌ范围内呈线性，检出限为０．３０ｍｇ／Ｌ。当进样体积为１００μＬ时，进样频率为６０次／ｈ，所建立的两     

反相流动注射-紫外光还原-分光光度法测定饮用水中的硝酸盐

1引言硝酸盐广泛存在于各种环境水体中。当饮用水中硝酸盐浓度过高时,可能对人体健康造成危害;地表水中硝酸盐大量积累,则可能引起藻类过度繁殖,溶解氧耗竭,水质恶化。目前,检测硝酸盐的最常用方法是将硝酸盐还原为亚硝酸盐,再经重氮偶联反应后由分光光度法进行测定[1]。此类方法已较好地与流动分析技术相结合,广泛应用于测定环境样     

Flow Injection Analysis of Famotidine with Spectrophotometric Detection

Abstract

A flow injection determination of famotidine has been described. The method is based on the reaction of the drug with cupric acetate to form a blue coloured complex which shows absorption maxima at 314 nm and 630 nm. For an injection volume of 100 μl calibration graphs were rectilinear from 10- 50 μg. ml^?1 and 50–500 μg.ml^?1 of drug at the two wavelengths respectively. Samples could be analysed at rates upto 60 per hour with a relative standard deviation less than 1.4%. The method was evaluated by analysis of the pure drug and commercial formulations. The results compare well with those obtained by official methods.     

芯片式流通池顺序注射化学发光法测定水中的亚硝酸根

微流控芯片(Microfluidic chips)是微全分析系统(μTAS)研究中最为活跃的领域,在仪器微型化方面展现出很多的优点^[1].化学发光由于其自身的特性在微芯片检测中应用逐渐增多^[2,3].     

Determination of Nitrite,Phosphate, and Silicate by Valveless Continuous Analysis with a Bubble-Free Flow Cell and Spectrophotometric Detection

A continuous flow analysis system, composed of a 1.2-cm laboratory-made antibubble flow cell and a spectrophotometer, was established. The system was evaluated for the determination of nitrite, phosphate, and silicate. Different from flow injection analysis and other flow analysis modes, an injection or multiposition valve was not needed. Even better, the system was free from interferences from air bubbles without the use of a debubbler device or electronic bubble gate. Without the formation of air bubbles, the chemical reaction was accelerated using a water bath. The experimental parameters for nutrient analysis, including reagent concentration, flow strategy, flow rate, and reaction temperature, were optimized based on a univariate experimental design. The carry-over effect was comprehensively evaluated and may be ignored using this protocol. The established system and analytical methods were especially suitable for laboratories with only basic instruments and limited budgets. The system had the advantages of high sample throughput (>60?h^?1); great convenience without valve utilization; long linear dynamic ranges (0.2–80?µM for nitrite, 0.3–14?µM for phosphate, and 0.5–120?µM for silicate); low detection limits (0.06?µM for nitrite, 0.08?µM for phosphate, and 0.11?µM for silicate); and high recovery values (91.5?±?1.01 to 108.7?±?3.18%). In addition to water samples, national reference materials were analyzed, and the results were in good agreement with the certified values.     

场放大样品进样-压力辅助毛细管区带电泳测定饮用水中的百草枯

1 引 言 百草枯属有机杂环类季铵盐除草剂,由于它具有优良的除草效果,已广泛应用于多种作物的杂草防治.百草枯具有极强的水溶性,极易迁移至水体环境中,从而对饮用水的质量安全构成潜在威胁.目前,百草枯的残留检测方法主要有分光光度法[1]、液相色谱-质谱联用法[2]、气相色谱质谱联用法[3]和毛细管电泳法(CE) [4～6].采用分光光度法测定百草枯,不仅操作繁琐费时,而且灵敏度低.采用气相色谱法测定百草枯,通常需要衍生化,应用较少[3].采用液相色谱法测定百草枯,通常需要在流动相中添加离子对试剂[2].毛细管电泳具有分离效率高,分析速度快等优点,已被广泛用于水样中百草枯残留的测定.然而,毛细管电泳灵敏度不高,极大地限制了其在实际样品分析中的应用.场放大样品进样(FASI)是一种简单有效的在线富集方法,其富集倍数可达1000倍[7],可有效提高毛细管电泳技术的灵敏度,因此应用较为广泛.本实验建立了场放大样品进样-压力辅助毛细管区带电泳法(CZE),用于测定饮用水中百草枯的残留量.     

A Sensitive Spectrophotometric Determination of Nitrite in Water and Soil

A highly sensitive spectrophotometric method for the determination of nitrite in water and soil has been developed. The reaction of nitrite with acidified potassium iodide to liberate iodine which oxidizes leuco‐crystal violet (LCV) to form crystal violet having absorption maxima at 590 nm forms the bases of this method. In aqueous medium the system obeys Beer's law in the range of 0.1 to 1.0 μg per 25 mL (0.004–0.04 ppm), while in an extractive system the range is 0.025–0.25 μg in 100 mL (0.00025–0.0025 ppm). The molar absorptivity and Sandell's sensitivity were found to be 1.54 × 10⁶ 1 mol^?1 cm^?1 and 44 pg cm^?2, respectively.     

Selective Kinetic Spectrophotometric Determination of Nitrite in Food and Water

Abstract

A highly selective and sensitive method for the kinetic spectrophothometric determination of sub-microgram amounts of nitrite has been development based on its reaction with Nile blue 2B in acidic medium. The reaction is monitored spectrophotometrically at 595 nm at a fixed time of 4.5 min. The change in absorbance at 595 nm is related to the concentration of nitrite in the range 0.005 - 1.100 μg.ml^?1 The detection limit is 0.001 μg.ml^?1. The relation standard deviation is 1% for 0.020 μg.ml^?1 of nitrite for ten replicate measurements. Most common anions and cations do not interfere. The procedure was applied to the determination of trace amounts of nitrite in sausage and water.     

Simultaneous Ultraviolet Spectrophotometric Determination of Nitrate and Nitrite in Water

Abstract

A rapid and accurate method for the direct simultaneous determination of nitrate and nitrite is proposed. The method is applied to the determination of nitrate and nitrite in rainwater and wastewater without preliminary separation. The determinations are performed by a CPA matrix method with ultraviolet spectrophotometric detection. The results obtained are in agreement with those obtained by conventional methods for the determination of nitrate and nitrite.     

长光程光导池吸光光度法测定天然水中痕量铬

用二苯碳酰二肼，对光导光度法测定天然水中痕量铬进行了研究。在光导吸收池中，光可在６０％二甲亚砜水溶液中实现全反射。应用１００ｃｍ长的光导池，测定铬的线性范围为０．２－２０μｇ／Ｌ，同１ｃｍ收池比较，灵敏度提高二个数量级，方法有高的选择性，水中常见共存离子均不干扰。     

Determination of Trihalomethanes in Drinking Water by Dispersive Liquid–Liquid Microextraction then Gas Chromatography with Electron-Capture Detection

Dispersive liquid–liquid microextraction (DLLME) has been used for preconcentration of trihalomethanes (THMs) in drinking water. In DLLME an appropriate mixture of an extraction solvent (20.0 μL carbon disulfide) and a disperser solvent (0.50 mL acetone) was used to form a cloudy solution from a 5.00-mL aqueous sample containing the analytes. After phase separation by centrifugation the enriched analytes in the settled phase (6.5 ± 0.3 μL) were determined by gas chromatography with electron-capture detection (GC–ECD). Different experimental conditions, for example type and volume of extraction solvent, type and volume of disperser solvent, extraction time, and use of salt, were investigated. After optimization of the conditions the enrichment factor ranged from 116 to 355 and the limit of detection from 0.005 to 0.040 μg L⁻¹. The linear range was 0.01–50 μg L⁻¹ (more than three orders of magnitude). Relative standard deviations (RSDs) for 2.00 μg L⁻¹ THMs in water, with internal standard, were in the range 1.3–5.9% (n = 5); without internal standard they were in the range 3.7–8.6% (n = 5). The method was successfully used for extraction and determination of THMs in drinking water. The results showed that total concentrations of THMs in drinking water from two areas of Tehran, Iran, were approximately 10.9 and 14.1 μg L⁻¹. Relative recoveries from samples of drinking water spiked at levels of 2.00 and 5.00 μg L⁻¹ were 95.0–107.8 and 92.2–100.9%, respectively. Comparison of this method with other methods indicates DLLME is a very simple and rapid (less than 2 min) method which requires a small volume of sample (5 mL).