ICP-OES常见干扰类型及校正方法探讨

电感耦合等离子体发射光谱仪(ICP–OES)越来越多地应用于各类物质的分析检测。测定复杂样品时,仪器出现各种干扰问题是影响测定结果准确性的主要因素。根据仪器原理及样品进入ICP的顺序,对可能出现的化学干扰、物理干扰、记忆效应、电离干扰和光谱干扰进行原因分析。结合具体实例探讨各类干扰相应的校正方法,可以较好地消除干扰对测定结果的影响。     

超声酸提取-电感耦合等离子体发射光谱(ICP-OES)法测定复配矿物质中铁锌

建立了复配矿物质中铁、锌的超声酸提取-电感耦合等离子体发射光谱测试方法。方法以10％硝酸为前处理试剂,利用超声辅助提取,优化了仪器检测的条件,消除干扰,并进行方法检出限、精密度和方法准确性等实验。方法的铁、锌检出限分别为1 mg /kg和0.5 mg/kg,线性范围为0.0~5.0 mg/L,相关系数(r)优于0.995。相对标准偏差RSD(%)均在5.0%以下,加标回收率在91.4% ~107.9%,实物加标回收与加标值一致。实验结果表明所建立的方法灵敏度高、简便、快速、准确,适用于复配矿物质中铁、锌的测定。     

热分析-傅里叶红外光谱-气相色谱-质谱联用技术分析果胶的热分解产物

将热分析-傅里叶红外光谱-气相色谱-质谱组成同步联用检测系统,对果胶在N2气和N2/O2氛围中,243、270和335 ℃ 3个温度点的热解产物经傅里叶红外光谱和GC-MS进行同步分析,在2种氛围下共检测鉴别了26种热分解产物。     

电感耦合等离子体原子发射光谱法(ICP-OES)与石墨炉原子吸收光谱法测定饮用水中重金属元素的比较

通过对比电感耦合等离子体原子发射光谱法(ICP-OES)与石墨炉原子吸收光谱法(AAS)测定水中重金属的检出限、重复性、加标回收率等实验,验证两种方法的准确性,从而为饮用水中重金属的测定提供可靠的方法。结果表明,石墨炉原子吸收光谱法测定饮用水中砷、镉、铬、铅、汞、硒的检出限均低于ICP-OES法,但ICP-OES法测定线性范围宽,重复性和加标回收率均优于石墨炉原子吸收光谱法,分析速度快,操作便捷,结果满意,是目前饮用水中重金属测定非常可靠的方法。     

ICP-OES and SEM-EDX Analysis of dust and powder produced by the laser-processing of a Cr-Ni-Steel alloy

In this investigation we compared the analytical results obtained by inductively coupled plasma optical emission spectroscopy (ICP-OES) and a scanning electron microscope with an energy dispersive X-ray analysis system (SEM-EDX). The powder and dust, obtained by laser-processing of CRN-14301 steel, was analysed to classify the powder and dust for its final waste disposal. For this reason we analysed the elemental content of the samples. The samples consisted of a mixture of metals and their oxides.The solid powder and dust was analysed directly by SEM-EDX, the ICP-OES analysis was carried out after the solid was dissolved in an acid solution. Both analytical methods were in good agreement.ICP-OES showed a higher precision and lower detection limit than EDX, but SEM-EDX showed a higher amount of information regarding the sample composition.     

电感耦合等离子体发射光谱法测定湿法精制磷酸中镁、钙、铁、砷含量

采用电感耦合等离子体发射光谱法(ICP-OES)测定湿法精制磷酸中微量元素镁、钙、铁、砷含量,对仪器参数及元素谱线等相关参数进行实验和优化,方法具有线性范围宽、精密度高、结果准确、分析速度快等特点。相对标准偏差RSD为0.26%～0.82%,加标回收率为95.75%～102.8%,检出限为0.0021～0.0408mg/L,适用于湿法精制磷酸中镁、钙、铁、砷的测定。     

草酸二甲酯与苯酚酯交换合成碳酸二苯酯反应产品的内标法测定

采用SP-3420型氢离子火焰气相色谱仪、HP-5型毛细管色谱柱,以苯甲酸乙酯为内标物,对草酸二甲酯与苯酚酯交换反应的产物草酸二苯酯进行定量分析。通过绘制内标法标准曲线,确定了标准方程为y=1.6366x 0.0319,相关系数为0.997。准确度和回收率实验表明,该方法的测定值与实际值的相对标准偏差在1%到4%之间;回收率在98%~102%。精密度实验表明,5次平行测定结果重复性良好,相对标准偏差为0.28%。分析和计算结果准确可靠,可以作为催化剂筛选、反应条件考察的基准。     

ICP–OES法测定锰钢中的铬、钼、磷

采用电感耦合等离子体发射光谱法测定锰钢中的铬、钼、磷。以盐酸–硝酸混合酸处理试样,通过选择元素的分析线来优化测试条件,利用基体匹配法消除基体干扰。结果表明,铬、钼、磷3种元素测定结果的相对标准偏差为0.86%~2.31%,加标回收率为96.7%~103.2%。该法能够满足日常分析对锰钢中铬、钼、磷含量测定的需要。     

化工,石油产品及硅酸盐分析

本文是《分析试验室》定期评述中“化工、石油产品及硅酸盐分析”课题的第六次评述，它评述了１９９５年７月至１９９７年６月国内关于化工产品、石油产品、硅酸盐的分析进展情况，共引用文献６７５篇。     

聚乙烯尼龙共混物的PGC-MS和FT-IR联用鉴别

采用裂解气相色谱-质谱法和红外光谱法研究聚乙烯和尼龙共混物的组成;据此建立鉴别聚乙烯共混物组分的方法;红外光谱法可以准确鉴别出尼龙组分,裂解气相色谱-质谱法可以准确鉴别出聚乙烯组分以及尼龙的具体结构;二种方法结合使用,可以准确鉴别聚乙烯和尼龙共混物的组分。     

Statistical FT-IR Spectroscopy for the Characterization of 17 Vegetable Oils

Vegetable oils have been utilized for centuries in the food, cosmetic, and pharmaceutical industries, and they contribute beneficially to overall human health, to active skincare, and to effective treatments. Monitoring of the vegetable oils is carried out by the methods described in the European Pharmacopeia, which is time-consuming, has poor repeatability, and involves the use of toxic organic chemicals and expensive laboratory equipment. Many successful studies using IR spectroscopy have been carried out for the detection of geographical origin and adulteration as well as quantification of oxidation parameters. The aim of our research was to explore FT-IR spectroscopy for assessing the quality parameters and fatty acid composition of cranberry, elderberry, borage, blackcurrant, raspberry, black mustard, walnut, sea buckthorn, evening primrose, rosehip, chia, perilla, black cumin, sacha inchi, kiwi, hemp, and linseed oil. Very good models were obtained for the α-linolenic acid and linoleic acid contents, with R² = 1.00; R_v² values of 0.98, 0.92, 0.89, and 0.84 were obtained for iodine value prediction, stearic acid content, palmitic acid content, and unsaponifiable matter content, respectively. However, we were not able to obtain good models for all parameters, and the use of the same process for variable selection was found to be not suitable for all cases.     

Analysis of urinary stone constituents using powder X-ray diffraction and FT-IR

Constituents of urinary stones obtained from various patients from western part of India, which is a highly urinary stone disease-prone area, have been analysed. Eight stones from four patients were collected through urologists and have been analysed using powder X-ray diffraction and FT-IR. Thermogravimetric analysis (TGA) and scanning electron microscopic (SEM) image of selected samples were also carried out. The analysis revealed that calcium oxalate monohydrate, which is also known as whewellite, is the common constituent of all of the stones, particularly at the initial stage of stone formation. However, multi phases viz. whewellite phase, and hydroxyl and carbonate apatite phases are also detected in the case of third and fourth patients, from where multiple stones were obtained. Interestingly, in these mixed phase stones the concentration of whewellite decreases with increasing the concentration of apatite phases. Thermal behaviour of the whewellite phase was studied by TGA and variable temperature XRD analysis. Morphology of the whewellite and apatite phases, examined by SEM image, has also been reported.     

Simultaneous determination of Cd,Cr, Cu,Ni, Pb and Zn in sewage sludge by slurry introduction ICP-OES method

In order to evaluate the slurry nebulisation method as an alternative method for analysis of sewage sludge, the metal content of sludge samples of different origins was determined. The concentrations of six elements: Cd, Cr, Cu, Ni, Pb, and Zn were determined by introducing the sludge as a slurry into an inductively coupled plasma optical emission spectrometer (ICP-OES). Calibration was performed by using aqueous standard solutions. For comparison, the sewage sludge was also digested by microwave digestion and introduced into the plasma as an aqueous solution. The accuracy of the method was checked by analysing a sewage sludge certified reference material (CRM 007-040 Sewage Sludge). The Student's t-test showed that values obtained using slurry nebulisation were close to the certified values at a 95% confidence level. The values of elements Cd 11.1?±?0.8; Cr 37.7?±?3.3; Cu 563.3?±?38.4; Pb 119.2?±?10.1; Zn 729?±?68.2?mg?kg^?1 obtained using this method were comparable with those obtained using the conventional method. The slurry method can, therefore, be successfully applied to the determination of content of each element in sewage sludge with RSD less than 3%, without the need to predissolve them. This could avoid the use of hazardous chemicals, incomplete dissolution and loss of volatile analytes.     

电感耦合等离子体原子发射光谱(ICP-OES)法测定铝合金中微量的钆、镧、钕、镨、钐

研究了电感耦合等离子体发射光谱(ICP-OES)法测定6系铝合金中微量的钆、镧、钕、镨、钐的方法,优化了ICP-OES工作条件,用标准加入法和标准曲线法做了比较,测定微量含量时,标准加入法比标准曲线法准确,在定量限和检出限之间约5倍空白标准偏差(5σ)含量时,标准加入法的加标回收率在80%~112%,检测结果具有参考价值.     

A New Approach to the Determination of Silicon in Zinc,Lead-Bearing Materials and in Waste Using the ICP-OES Method

This work describes the implementation of the ICP-OES silicon determination method for zinc and lead-bearing materials and waste at the Mining and Metallurgical Works ZGH “Bolesław”. The proposed method was validated. On the basis of linearity tests, it was found that the course of the calibration curve is linear up to a silicon concentration of 100 mg/L, with the determined working range being 0.10–50%. Precision tests, on the basis of which the repeatability was checked, were carried out for nine types of real samples: zinc sulfides, zinc oxides, zinc-lead ore, lead sulfide and zinc-bearing waste. Real samples and six certified reference materials were tested using the ICP-OES radial position. The identified interferences of molybdenum, chromium and vanadium did not statistically significantly affect the measurement results.     

Development and Validation of HPLC,TLC and Derivative Spectrophotometric Methods for the Analysis of Ezetimibe in the Presence of Alkaline Induced Degradation Products

Reversed phase‐high performance liquid chromatography (RP‐HPLC), thin layer chromatography (TLC) densitometry and first derivative spectrophotometry (1D) techniques are developed and validated as a stability‐indicating assay of ezetimibe in the presence of alkaline induced degradation products. RP‐HPLC method involves an isocratic elution on a Phenomenex Luna 5μ C₁₈ column using acetonitrile: water: glacial acetic acid (50:50:0.1 v/v/v) as a mobile phase at a flow rate of 1.5 mL/min. and a UV detector at 235 nm. TLC densitometric method is based on the difference in Rf‐values between the intact drug and its degradation products on aluminum‐packed silica gel 60 F₂₅₄ TLC plates as stationary phase with isopropanol: ammonia 33% (9:1 v/v) as a developing mobile phase. On the fluorescent plates, the spots were located by fluorescence quenching and the densitometric analysis was carried out at 250 nm. Derivative spectrophotometry, the zero‐crossing method, ezetimibe was determined using first derivative at 261 nm in the presence of its degradation products. Calibration graphs of the three suggested methods are linear in the concentration ranges 1–10 mcg/mL, 0.1–1 mg/mL and 1–16 mcg/mL with a mean percentage accuracy of 99.05 ± 0.54%, 99.46 ± 0.63% and 99.24 ± 0.82% of bulk powder, respectively. The three proposed methods were successfully applied for the determination of ezetimibe in raw material and pharmaceutical dosage form; the results were statistically analyzed and compared with those obtained by the reported method. Validation parameters were determined for linearity, accuracy and precision; selectivity and robustness and were assessed by applying the standard addition technique.     

化工、石油产品及硅酸盐分析

本文是《分析试验室》定期评述中“化工、石油产品及硅酸盐分析”课题的第七次评述,评述了１９９７ 年７ 月至１９９９ 年６ 月国内关于化工产品、石油产品、硅酸盐的分析进展,引用文献７０９ 篇。     

Photolysis-assisted, long-path FT-IR detection of air pollutants in the presence of water and carbon dioxide

Seven important air pollutants have been investigated by photolysis-assisted FT-IR spectroscopy. This technique renders invisible the spectra of water and carbon dioxide, which are two of the main concerns in long-path infrared spectroscopy. A cell, equipped with a UV lamp, was used to oxidise the analyte in the air sample and the spectrum recorded was used as a new background for the original sample spectrum. The optimum UV irradiation time and correctness of the concentrations were determined for this technique and compared with those from traditional methods. The signal-to-noise (S/N) ratios of the so-called “shadow spectra” were better than, or at least comparable to, the S/N ratios in the absorbance spectra obtained by using as background an air or an evacuated cell reference and subtraction of the spectra of water and carbon dioxide from a spectral library. The detection limits for the volatile organic compounds investigated have been improved by using this new method in which an appropriate background spectrum can be obtained quickly. The limitations of the method are that it cannot be applied to non-UV reactive compounds, such as methane, and the detection limits can be appreciably degraded when bands due to ozone in the shadow spectra overlap with those of the compounds under investigation.     

FT-IR Spectrophotometric Analysis of Ascorbic Acid and Biotin and their Pharmaceutical Formulations

Abstract

Fourier transform–infrared (FT-IR) spectrometry was used for the rapid, direct measurement of ascorbic acid (vitamin C) and biotin (vitamin H) in different pharmaceutical products. Conventional KBr spectra were compared for the best determination of active substances in drug preparations. The Beer–Lambert law and chemometric approaches were applied in data processing.