提高原子吸收光谱仪测定冰雪样品的灵敏度

冰雪样品离子含量低,用原子吸收光谱测定阳离子,有些离子不能得到满意的结果,改用撞击球替代绕流器雾化,通过一系列试验对比,结果Ｃａ＾＋吸光度提高１．２倍,解决了冰雷样品离子含量低,测定难的问题。     

声光可调滤光片作为电热原子吸收光谱仪波长选择器的研究

研究了声光可调滤光片（AOTF）的性能，并以AOTF为波长选择系统，钽丝为原子化器，用原子吸收光谱法测定了Na。考察了空心阴极灯电流，保护气流量，钽丝原子化器和干燥电压和原子化电压对Na吸收信号的影响。在选定的最佳实验条件下，测定Na的特征浓度为0.045μg/mL，精密度为2．6％（n=8)。在0.050-1.0μg/mL范围内，Na的浓度与吸光度值有良好的线性关系。     

原子吸收光谱仪的最新技术进展

德国耶拿公司推出了全球第一台商品化的ContrAA型连续光源火焰原子吸收光谱仪，该仪器的诞生标志着人类在原子吸收光谱技术方面又向前迈进了一步。     

便携式钨丝电热原子吸收光谱仪测定天麻中的铅

采用微波消解-小型钨丝电热原子吸收光谱仪在优化条件下测定了天麻中的铅。进样10μL时,检出限为10.1μg/L。对600μg/L铅标准溶液进行5次连续测定,测定结果的相对标准偏差为5.2%。铅的线性范围为100~1500μg/L,回归方程为A=0.0002c-0.0103,线性相关系数r=0.995 8。该法测定结果与电感耦合等离子体发射光谱仪(ICP-OES)测定结果接近,该方法简便、快速,可用于天麻样品中痕量铅的测定。     

连续光源原子吸收光谱仪——划时代的技术革命

原子吸收光谱仪经过半个世纪的发展已成为微量和痕量分析的重要常规设备，其在理化分析实验室的普及程度据原子光谱分析仪器的首位。     

连续光源原子吸收光谱仪——划时代的革命性产品

原子吸收光谱仪经过半个世纪的发展已成为微量和痕量分析的重要常规设备，其在理化分析实验室的普及程度居原子光谱分析仪器的首位。     

氢化物-原子吸收光谱仪测定食品中的汞

本文研究了采用氢化物原子吸收光谱法测定食品中痕量汞,通过采用氢化物发生器,选择合适浓度的载流和硼氢化钾,获得了较为满意的分析结果。采用此方法测定汞含量在5-20μg/kg的食品标准样品,测试结果相对标准偏差2.21-3.65%,回收率84.9-97.5%,检出限0.2 μg/L,完全满足食品行业汞元素痕量检测要求,操作简便、快速。     

间接原子吸收法测定尼可刹米

利用间接原子吸收法测定了药物制剂中尼可刹米的含量。该法基于尼可刹米在酸性介质中与Cu2 及SCN-生成1∶1∶2络合物,通过CH3Cl萃取,测定水相中剩余Cu2 的量来间接测定尼可刹米。本法在0～90μg mL范围内呈良好的线性关系(R2=0.9992)。并探讨了尼可刹米和Cu2 及SCN-生成络合物的反应机理。已用于药物制剂中尼可刹米的测定。     

原子吸收法间接测定呋喃唑酮

运用原子吸收法间接测定了呋喃唑酮片剂中的呋喃唑酮。方法基于呋喃唑酮在N,N-二甲基甲酰胺（DMF）与乙醇的混合溶剂中与Zn-NH4Cl反应生成胲,胲与Tollens试剂按1：2的关系反应生成单质Ag沉淀,通过测定上清液中剩余Ag的原子吸收光度来间接测定呋喃唑酮。已用于呋喃唑酮片剂中呋喃唑酮的测定。     

Mahganese Determination In Blood Serum Using Electrothermal Atomic Absorption Spectrometry

Abstract

Twelve procedures of sample pretreatment for manganese determination in blood serum were tested in comparable instrumental conditions. the best results were obtained by dilution of serum with diluted nitric acid, which leads to formation of an internal matrix modifier composed of calcium and phosphoric acid. Other procedures may also give satisfactory results, but then as standards aqueous albumin solutions should be used.     

Factorial and Doehlert Design Used as Optimization Procedures for the Direct Determination of Lead in Whole Blood Samples by Graphite Furnace Atomic Absorption Spectrometry

In this work, the direct determination of lead in whole blood samples by graphite furnace atomic absorption spectrometry is proposed. The samples were diluted 1:9 with HNO₃ and Triton® X-100, both 0.2% v/v. Multivariate optimization was made to evaluate the pyrolysis and atomization temperatures and the use of a chemical modifier. The method allowed lead determination with a curve ranging from 0 to 6.0 μg dL^?1. Recovery studies presented results from 88 to 109%. The LOD and the characteristic mass were 0.21 μg dL^?1 and 7.4 pg, respectively. Intra- and inter-assay studies showed respective coefficients of variation of 4.2 and 8.9%.     

Optimization of Fiber-Water Dispersion Process Using Box-Behnken Design of Experiments Coupled with Response Surface Methodology of Analysis

In this work, the fiber-water dispersion process with reference to the wet-lay technology was optimized in order to improve the uniformity of the wet-laid webs by using Box-Behnken design of experiments coupled with response surface methodology of analysis. A series of wet-laid webs were prepared by using cotton fibers of 7 mm cut length and 5.6 micronaire linear density and employing different combinations of three process variables of interest namely stirring rate, dispersion time, and surfactant concentration. The resulting webs were tested for their area-based uniformity by means of quadrat analysis. The response surface model was found to be statistically significant at a P value as low as 0.0213. The experimental results were found to be in good agreement with the model results. The single effect of surfactant concentration, interaction effect of surfactant concentration and stirring rate, and quadratic effect of dispersion time were found to be statistically significant at 0.05 level of significance. The optimum level of coefficient of variation of the area occupied by the fibers in the web was predicted as 10.50% at stirring rate of 250 rpm, dispersion time of 5 minutes, and surfactant concentration of 0.10 and this was experimentally observed as 11.02%.     

原子荧光光谱仪的便携化设计

针对重金属污染现场快速检测领域的发展需求,成功开发首台便携式原子荧光光谱仪。实现了高度集成低功耗进样系统、微型低功耗原子化系统、数字化对光技术、微型光电检测系统以及无线通讯技术等十余项关键技术的重大突破。整机功率仅为12 W,重量仅为10kg,锂电池供电状态下工作时间不小于8h,具备与实验室常规原子荧光光谱仪相同的性能指标,可直接用于砷、汞、铅、镉等重金属的野外现场快速检测。     

Atomic Absorption Spectrometric and Spectrophotometric Trace Analysis of Indium in Environmental Samples

Abstract

Indium (III) was selectively extracted at pH 5.2–5.9 with N-p-methoxyphenyl-2-furylacrylohydroxamic acid (MFHA) into chloroform. BPAR [5-bromo-4(2-pyridylazo) resorcinal] was added to the extract to form an intensely red coloured ternary complex measurable spectrophotometrically at 515 nm (? = 5.81 × 10⁴ 1 mol^?1 cm^?1). The extraction system enabled enrichment of indium and determination of the metal down to 10^?4 ppm (0.1 ppb) levels. For atomic absorption spectrometric determination, indium was extracted with MFHA into methyl isobuyl ketone and measured at 303.9 nm resonance line in the air-acetylene flame. Both the methods were     

Synergistic Extraction and Atomic Absorption Spectrometric Determination of Managanese in Environmental Samples Using M-p-Aminophenyl-2-Furylacrylohydroxamic Acid and Trioctylmethylammonium Cation

Abstract

Fifteen new hydroxamic acids were explored in conjunction with trioctyimethylammonium cation for the extractive separation of manganese into MIBK from the anions and cations commonly associated with the metal in environmental samples. The most rapid extraction with the maximum selectivity and sensitivity for the atomic absorption spectrometric determination of the metal in the MIBK extract was achieved with N-p-aminophenyl-2-furylacrylohydroxamic acid. The method enabled the determination of manganese at sub-ppb levels and was applied in the analysis of coal, manganese ore, plant tissue, animal tissue and natural waters.     

Design and Optimization of Ecofriendly One-Pot Synthesis of 2,4,5-Triaryl-1H-imidazoles by Three-Component Condensation Using Response Surface Methodology

Phase-transfer-catalyzed, highly versatile, and high-yielding protocol for the synthesis of 2,4,5-triaryl-1H-imidazoles was developed through response surface methodology (RSM). The effects of different solvents, reaction paths, and phase-transfer catalysts (PTCs) in different concentrations were envisioned. Three independent variables (catalyst, catalyst loading, and solvent volume) identified by one-factor-at-a-time (OFAT) study were screened through full factorial design at two levels. The analysis of variance results suggested the significance of catalyst PEG400 and solvent glacial acetic acid at 5 h reaction. The optimum reaction conditions suggested by the RSM were the use of PEG400 (10.61 mol%) and glacial acetic acid (10.71 mL) for 5 h cycloocondensation. The experimental yield of 4,5-diphenyl-2-nitrophenyl-1H-imidazole (97%) was in agreement with predicted yield (97.5%).     

Atomic Absorption Spectrometric and Synergistic Spectrophotometric Microdetermination of Hafnium in Alloys and Environmental Samples

Abstract

Hafnium (IV) was selectively extracted from 0.45–0.55 M HC1 media as its chelate with N-p-methoxyphenyl-2-furylacrylo-hydroxamic acid (MFHA) into chloroform. Xylenol orange was added to the extract to form an intensely coloured ternary complex measurable spectrophotometrically at 545 nm (? = 8.3×10⁴1 mol^?1 cm^?1) with a sensitivity better than 0.002 ppm. For atomic absorption spectrometric determination, hafnium was extracted with MFHA into methyl isobutyl ketone and measured with 286.6 nm resonance line in the nitrous oxide-acetylene flame. The methods were applied to the analysis of hafnium in alloys, plant tissues, animal tissues and natural waters. The MFHA-xylenol orange reagent combination was chosen after studying ten hydroxamic acids and five chromogenic reagents.     

Direct Determination of Ultra Trace Nickel in Serum by Controlled-Temperture Graphite Furnace of Atomic Absorption Spectrophotometry

Abstract

This paper describes a method of direct determination of serum Ni by controlled- temperature graphite furnace of AA. Ammonium oxalate is used as a matrix modifier to eliminate interferences caused by chlorides of alkali and alkaline earth in sample. The operating procedure has been applied to determine Ni contents of serum from 190 adults in Hefei district of China and good results have been obtained.     

Indirect Atomic Absorption Spectrometric (AAS) Determination of Atenolol

Abstract

The Cu(II)-atenolol complex was prepared, and characterized by elemental analysis and spectroscopic techniques (via. IR, electronic and EPR spectra). The spectral results obtained indicate tetrahedral geometry around the Cu(II) ion. An indirect atomic absorption spectrometric method was undertaken to estimate atenolol in pharmaceutical preparations, based on its reaction with Cu²⁺ in alkaline medium. The method is simple, rapid, accurate and sensitive.