Studies on some experimental parameters of radiometric flow injection analysis (RFIA) using137Cs and60Co

A simple radiometric flow injection analyzer with NaI(Tl) detector was used for the study of some experimental parameters of¹³⁷Cs and⁶⁰Co determination. A sample transfer system was developed employing both merging zone and sample injection principle.     

Removal of60Co and134Cs from radioactive process waste water by flotation

The removal of¹³⁴Cs and⁶⁰Co from radioactive process waste water using cetyl pyridinium chloride (CPC) as a collector and cobalt(II) hexacyanoferrate(II) as a precipitant for⁶⁰Co and sorbent (ion exchanger) for¹³⁴Cs was intensively investigated and the best removal conditions could be established. The results indicate that under the optimum conditions removals higher than 96% and 97% could be achieved for Co(II) and Cs(I), respectively. Cobalt(II) hexacyanoferrate(II) was found to have high affinity for cesium and can preferentially remove it in presence of relatively high amounts of other alkali or alkaline earth cations. A two-stage flotation process was successfully tested for the removal of both Cs(I) and Co(II) from waters containing both cations.     

Reverse radiometric flow injection analysis (RFIA) of radioactive waste-waters with an ASIA (Ismatec) analyzer

A new application of reverse radiometric flow injection analysis is described. RFIA was used for the analysis of radioactive waste-waters. ASIA (Ismatec) analyzer with NaI(Tl) scintillation detector was used in the study of analysis of¹³¹I containing waste-water.     

Determination of Co and Cs by stopped-flow RFIA with the aid of multi-channel analyzer

Radiometric flow-injection analysis (RFIA) was used for the transport of carrier and sample solution. Radioactive nuclides⁶⁰Co and¹³⁷Cs were used as indicators and a NaI (Tl) scintillation detector coupled to a Canberra MCA for measuring the activity of¹³⁷Cs at 662 keV and⁶⁰Co at 1173 keV and 1332 keV. Experimental parameters related to RFIA were studied, too.     

Simultaneous determination of nitrate and nitrite by flow injection analysis

An automatic method for the simultaneous determination of nitrate and nitrite by flow injection analysis is described. Nitrate is reduced to nitrite with a copperized cadmium column. Nitrite is diazotized and coupled with N-(l-naphthyl)ethylenediammonium dichloride. The merging zones approach is used to minimize reagent consumption. The injector system is arranged so that two peaks are obtained, one corresponding to nitrite and the other to nitrite plus nitrate. A sampling rate of about 90 samples per hour is possible; the precision is better than 0.5% for nitrite in the range 0.1–0.5 mg l^t and 1.5% for nitrate in the range 1.0–5.0 mg l^t     

流动注射法在线测定氨性废水中的镍

在过硫酸铵存在下,丁二酮肟与氨性水溶液中微量镍生成可溶性酒红色络合物。据此采用反相流动注射光度分析法,建立了在线测定氨性废水中镍的方法。在最大吸收波长440nm处进行在线光度测定,采样频率60次 h。方法测定下限为0.04μg mL,RSD小于1%,加标回收在95%～105%。方法可用于水样分析。     

Simultaneous spectrophotometric determination of calcium and magnesium with chlorphosphonazo-III by flow injection analysis

In this flow-injection method, the total concentration of calcium and magnesium is determined by using triethanolamine/hydrochloric acid buffer (pH 7.0) and chlorphosphonazo-III (CPA-III) in the flow streams, and the concentration of calcium alone is determined by using 1.6×10^?3 M hydrochloric acid and CPA-III in the flow treams. At pH 7.0, medium, the linear calibration ranges were 0–2.00 mg l^?1 for both calcium and magnesium and the detection limits were each 0.02 mg l^?1; at pH 2.2, the linear calibration range for calcium and the detection limit were 0.20–2.00 mg l^?1 and 0.1 mg l^?1, respectively. Injection rates are 200 h. The method is suitable for analyzing natural waters.     

Simultaneous enzymatic determination of methanol and ethanol by flow injection analysis

A differential-kinetic enzymatic method for the resolution of methanol-ethanol mixtures based on the use of a reactor containing alcohol oxidase immobilized on controlled-pore glass is proposed. The method also involves the aldehyde/p-rosaniline/sulfite-coupled reaction and a twofold halting of the flow (in the enzymatic reactor to favor the oxidation reaction and in the detector flow cell to perform kinetic measurements) per sample assayed. The determination range is between 10 and 60 and 10 and 300 μg/ml for methanol and ethanol, respectively. Equations of the calibration curves for the mixtures have been derived where the concentration of each analyte is a function of the absorbance monitored at different stop times in the detector.     

Simultaneous spectrophotometric determination of nitrite and nitrate by flow injection analysis

The flow injection principle is used in the photometric determination of nitrite and nitrate with sulfanilamide and N-(1-naphthyl)ethylenediamine as reagents. An on-line copper-coated cadmium reductor reduces nitrate to nitrite. The detection limit is 0.05 μM for nitrite and 0.1 mM for nitrate at a total sample volume of 200 μM. Up to 30 samples can be analyzed per hour with a relative precision of ca. 1%.     

Simultaneous spectrophotometric determination of nitrite and nitrate by flow injection analysis.

A new catalytic spectrophotometric method is reported for the simultaneous determination of nitrite and nitrate by flow injection analysis, based on the catalytic effect of nitrite on the redox reaction between pyrogallolsulfonephthalein and potassium bromate in acidic media. Nitrate can also be on-line reduced to nitrite with a modified copper-coated cadmium reduction column. The reaction was monitored spectrophotometrically by measuring the decrease in the absorbance of pyrogallolsulfonephthalein at 465 nm. Various analytical parameters such as effects of acidity, reagent concentrations, flow rates, sample sizes, lengths of the reaction coil and temperatures were studied and were optimized. Under the optimized conditions, the calibration graph was linear for 2.4 to 160 ng ml(-1) of nitrite and 4.0 to 100 ng ml(-1) of nitrate. The influences of potential interfering cations and anions for nitrite and nitrate determination were studied. The method is successfully applied for food and water samples. Up to ten samples can be analyzed per hour.     

Simultaneous determination of iron and copper ions by low-injection analysis with a multichannel photodiode-array detector

Iron(II) and copper(II) ions are determined simultaneously in a simple manifold by using a multichannel photodiode-array detector. 1-(2-Pyridlazo)-2-hydroxy-7-sulfonaphthalene (PAN-7S) is used as the sole chromogenic reagent. The absorbance at 550 nm is related to the PAN-7S chelates of iron(II) and copper(II)and that at 764 nm to the iron(II) chelate alone. Calibrations are linear over the range 0–8.0 x 10^?6 M for each metal. Interference from zinc is avoided by addition of nitrilotriacetic acid; nickel interferes. Appliation to the determination of iron and copper ions in blood serum is discussed.     

流动注射光度法测定水样中的肼

利用肼类化合物在酸性介质中与香草醛反应形成黄色腙类化合物,在波长410nm处具有最大的光度吸收,建立了流动注射分析(FIA)技术与分光光度法联用直接测定环境水样中的微量肼的在线分析方法.结果表明,在最佳检测条件下,肼在2～1500μg/L范围内有良好的线性关系,相关系数R<'2>=0.9998,检测限为0.7μg/L,每小时进样20次,100μg/L的肼样品相对标准偏差(RSD)为0.92%(n=11).利用该方法分析河水、井水、池塘水、污水中的肼,回收率为97.3%～106.1%,结果与国家标准法一致.     

Kalman滤波流动注射化学发光法同时测定铂钯的研究

利用Luminol H2O2 OP Pt(Pd)化学发光新体系以及Kalman滤波化学计量学方法建立了流动注射化学发光法同时测定铂钯的新方法。方法的检出限:铂为2.2×10-8g mL、钯为2.4×10-8g mL,铂钯相对标准偏差分别为0.9%和3%。采用阳离子交换树脂静态吸附分离,消除贱金属离子的干扰。可用于贫铂矿中铂、钯的同时测定。     

流动注射-分光光度法在线监测水中微量铝

建立了流动注射-分光光度法在线测定水中铝离子的方法,经过优化实验条件,方法的线性范围为0.01 ～0.6 mg/L,检出限为0.004 mg/L.本法试剂消耗量少,分析速度快,灵敏度高,抗干扰能力强,适宜于现场的即时检测,回收率在97.7％ ～101.7％之间.     

Catalytic determination of silver(I) by extractive flow injection analysis

A new catalytic method for the determination of silver(I) was developed based on a metal exchange reaction between ethylenediaminetetraacetatomercury(II) (Hg(II)-EDTA) in the aqueous phase and bis(diethyldithiocarbamato)copper(II) (Cu(II)-DDTC) in the organic phase. This exchange reaction (Cu(II)-DDTC(org)+Hg(II)-EDTA-->Hg(II)-DDTC(org)+Cu(II)-EDTA, where org denotes the organic phase) was observed to proceed slowly and the Cu(II)-DDTC complex transferred quantitatively to Hg(II)-complex in the organic phase in the equilibrium state. In this system, silver(I) acts as the catalyst and can be determined by measuring the decrease in the absorbance of the Cu(II)-DDTC complex (lambda(max)=435 nm). The reaction was applied to the extractive flow injection analysis of silver(I). The present method allows the determination of silver(I) at 10(-7) mol dm(-3) level with the sampling frequency of 30 h(-1). The relative standard deviation of 0.28% (n=10) was obtained at 4.0x10(-7) mol dm(-3) of silver(I).     

反向流动注射化学发光法测定二邻苯二甲酰亚胺甲基二磺酸基酞菁锌

在碱性介质中 ,二邻苯二甲酰亚胺甲基二磺酸基酞菁锌 (简写为ZnPcS2 P2 )可增强Luminol H2 O2 CTAB体系的化学发光 ,据此建立了测定ZnPcS2 P2含量的反向流动注射化学发光分析新方法。用该法测定ZnPcS2 P2 ,其范围为 2 .5× 1 0 - 7～ 1 .0× 1 0 - 8mol/L ,检测限为 9× 1 0 - 9mol/L ,对 1 .0× 1 0 - 7mol/L的Zn PcS2 P2 溶液进行 9次平行测定 ,其相对标准偏差为 1 .2 %。本法有一定的选择性 ,与分光光度法相比 ,灵敏度提高了 1～ 2个数量级。     

反相流动注射胶束增敏化学发光分析法测定硝苯地平

基于胶束介质中硝苯地平对碱性鲁米诺-过氧化氢化学发光体系的增敏作用,结合反相流动注射技术,建立了流动注射化学发光分析法测定硝苯地平的新方法.硝苯地平浓度在3.5×10-10～4.0×10-8 g·mL-1范围内时,化学发光强度与硝苯地平的浓度呈良好的线性关系,其相对标准偏差为1.4%(n=11,c=3.5×10-9 g...     

Simultaneous determination of phenolic compounds in water by normal and derivative flow injection/cyclic votammetry

The possibilities for using fast-scan voltammetric detectors in flow injection analysis for individual and multicomponent determination of phenolic compounds are explored. A cyclic voltammetric unit for potential scans is connected to a three-electrode cell (carbon-paste working electrode, silver/silver chloride reference electrode and glassy-carbon auxiliary electrode). The resolution and hence the selectivity obtainabel from the electrode processes can be improved by derivatizing the current/potential recordings. Individual and simultaneous determinations of phenol, guaiacol and 2,4-dichlorophenol at levels lower than 1 μg ml^?1 can be achieved by judicious selection of measurement potentials, and in worst cases, by use of simultaneous equations.     

Rapid determination of chromium(VI) in electroplating waste water by use of a spectrophotometric flow injection system

A new rapid and sensitive FI method is reported for spectrophotometric determination of trace chromium(VI) in electroplating waste water. The method is based on the reaction of Cr(VI) with sodium diphenylamine sulfonate (DPH) in acidic medium to form a purple complex (lambda(max) = 550 nm). Under the optimized conditions, the calibration curve is linear in the range 0.04-3.8 microg ml(-1) at a sampling rate of 30 h(-1). The detection limit of the method is 0.0217 microg ml(-1), and the relative standard deviation is 1.1% for eight determinations of 2 microg ml(-1) Cr(VI). The proposed method was applied to the determination of chromium in electroplating waste water with satisfactory results.