ICP-AES法测定牙膏中的铅、铜、锌

目的采用合适的样品前处理方法和电感耦合等离子原子发射光谱仪(ICP-AES)测定牙膏中铅、铜和锌。方法选择微波消解法、酸湿式消解法和干式消解法对样品进行前处理,对比这几种方法的结果。优化仪器测定参数以适应此类样品测定。测定方法的线性范围、相关系数、检出限、精密度、加标回收率等,探讨了相关结果的影响因素。并且与原子吸收比对。结果本法采用线性范围为0～2.000 mg/L,样品测定6次,所有元素相对标准偏差小于2.56%,加标回收率在95.95%～104.53%之间。结论用ICP-AES同时测定牙膏铅、铜和锌3种元素,具有良好的准确度和精密度,灵敏度高、检出限低、线性范围宽、元素之间的干扰少,样品前处理采用微波消解法,是高效可行的方法。     

地球化学样品中钒检测方法的对比

地球化学样品中钒的测定方法主要有原子吸收光谱法、等离子体发射光谱法(ICP-AES)、电感耦合等离子体质谱法(ICP-MS)和X射线荧光光谱法.选用国家一级标样,分别用4种方法测定样品含量值,依次对方法检出限、准确度、精密度、加标回收率作比较.经对比,4种方法测定值与推荐值都基本吻合.等离子体发射光谱法检出限低,线性范围更宽,准确度与精密度更好,更适用于地球化学样品中钒批量的测试.     

电极法与化学法测血清总钙的实验对比

为了解电极法分析血清总钙的特点，将该法与邻甲酚酞法进行了实验对比，结果两种方法线性范围和平均回收率均符合要求，精密度实验批内和批间ＲＳＤ值均在允许范围。电极法快速，准确，化学法稳定性好，抗干扰性强，两种方法相关性良好，无显著差异。高脂血标本对两种方法均有正干扰。     

ICP-AES法同时测定阴极铜中杂质元素

阴极铜是重要的工业原料,它的杂质元素含量对其品位确定是非常关键的指标,国内外有关阴极铜中杂质化学成分的测定方法大多用分光光度法和原子吸收光谱法。化学方法分析流程冗长,并用许多有机试剂,操作繁琐。ICP-AES法具有检出限低,线性范围宽,精密度好,可多元素同时测定,分析速度快等特点。本文采用ICP-AES法测定阴极铜中杂质元素,满足了生产的需要。     

地球化学样品中铷元素的测定方法选择研究

针对易电离元素铷,采用原子吸收光谱法和电感耦合等离子体原子发射光谱法两种测定方法进行了探讨。用原子吸收光谱法测定铷需要加入硫酸钾作电离抑制剂,操作繁杂但检出限(0.2μg/mL)更低,线性范围窄;采用(HCl-HNO3-HF-HClO4)溶样,电感耦合等离子体原子发射光谱法测定简便快速,检出限为1.2μg/mL,适合大批量多元素快速测定。两种方法结合使用可实现大批量样品中铷的快捷、简单、准确测定。     

电感耦合等离子体原子发射光谱法测定炭质页岩物相中钒的准确度评价

正地质样品中钒的测定方法主要有容量法、极谱法、分光光度法、电感耦合等离子体原子发射光谱法(ICP-AES)。在炭质页岩物相分析中,各物相中钒量(质量分数为1～104mg·kg-1)差异较大,而传统的容量法、分光光度法、极谱法分析程序复杂,操作要求较高,干扰不容易消除,难以完全满足物相分析的要求[1-2]。ICP-AES具有精密度好、稳定性高、线性范围宽、检出限低等优势[3-5],被广泛用于物相分析。     

王水消解-冷原子吸收光谱法测定土壤中汞

为了寻求一种更加适宜测定土壤中汞含量的测试方法,将检出限低、精密度高的冷原子吸收光谱法与便捷、高效的王水水浴消解土壤处理方式相结合,建立了王水消解-冷原子吸收光谱法测定土壤中汞。通过测定方法的线性相关性、方法检出限、准确度、精密度、加标回收率,并与原子荧光光谱法进行对比实验来评价该方法的有效性。王水消解-冷原子吸收光谱法在汞质量浓度0.0~1.0μg/L范围内线性良好,相关系数可以达到0.9999,方法检出限为0.00075 mg/kg,土壤标准样品测试的相对标准偏差为4.0%~10.7%,实际样品加标回收率分别为93%~104%。采用原子荧光光谱法进行对比测试,原子荧光光谱法的方法检出限为0.0025 mg/kg,相对标准偏差为4.8%~13.5%,加标回收率为104%~107%。结果表明,对于王水水浴消解土壤的方法不仅适用于原子荧光光谱法测定汞含量,同样可以应用于冷原子吸收光谱法中。所建立的王水消解-冷原子吸收光谱法具有更低的检出限,更优的准确度和精密度,有利于提高土壤样品测试的工作效率,值得推广。     

王水消解-冷原子吸收光谱法测定土壤中汞

为了寻求一种更加适宜测定土壤中汞含量的测试方法,将检出限低、精密度高的冷原子吸收光谱法与便捷、高效的王水水浴消解土壤处理方式相结合,建立了王水消解-冷原子吸收光谱法测定土壤中汞。通过测定方法的线性相关性、方法检出限、准确度、精密度、加标回收率,并与原子荧光光谱法进行对比实验来评价该方法的有效性。王水消解-冷原子吸收光谱法在汞质量浓度0.0～1.0μg/L范围内线性良好,相关系数可以达到0.999 9,方法检出限为0.000 75mg/kg,土壤标准样品测试的相对标准偏差为4.0%～10.7%,实际样品加标回收率分别为93%～104%。采用原子荧光光谱法进行对比测试,原子荧光光谱法的方法检出限为0.002 5 mg/kg,相对标准偏差为4.8%～13.5%,加标回收率为104%～107%。结果表明,对于王水水浴消解土壤的方法不仅适用于原子荧光光谱法测定汞含量,同样可以应用于冷原子吸收光谱法中。所建立的王水消解-冷原子吸收光谱法具有更低的检出限,更优的准确度和精密度,有利于提高土壤样品测试的工作效率,值得推广。     

高效液相色谱-加热电喷雾串联三重四级杆质谱法测定蔬菜中18种常用农药残留

建立了蔬菜中18种农药残留的高效液相色谱-加热电喷雾串联三重四级杆质谱测定方法.样品由乙腈提取,氨基柱净化,经C18液相色谱柱分离后,加热电喷雾离子源正负离子同时采集,在选择反应监测模式下进行测定.结果表明,该方法简便、快速、灵敏,方法的线性范围、回收率、精密度和检出限均符合农药残留分析的要求.     

电感耦合等离子体发射光谱法(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(GF-AAS)测定水中重金属的检出限、精密度、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。     

定量分析方法评价

对定量分析方法的评价，应该综合考虑精密度，准确度，灵敏度，线性范围，检出限，基体效应和耐变性等因素，一种具有推广价值的方法，应当简便，实用。     

Electrochemical Detection of Steroid Hormones Using a Nickel‐Modified Glassy Carbon Electrode

This paper demonstrates the development of an analytical method for detecting steroid hormones by coupling HPLC to electrochemical detection, using a nickel‐modified glassy carbon electrode. The method was evaluated in terms of sensitivity, linear dynamic range, limit of detection, and response stability. The developed method exhibited good figures of merit for the steroid hormones studied with no evidence of electrode fouling. As an example, the limit of detection (S/N=3) for E3 was 0.10 µM and the response precision (n=5) was 0.6 %. The application of the method for the analysis of a real river water sample is demonstrated.     

Study on fluorescent property of degrading products of piperacillin and its analytical application

The fluorimetric property of the degrading products of piperacillin has been studied in detail. The studies on degrading pH, degrading time, detection alkalinity and other corresponding analytical parameters of acid degradation have been made. Then fluorometry of piperacillin was established by producing its stable fluorescent products. The detection limit for acid degradation analytical method is 2.34 ng/ml, the linear range is 7.80-4.0 x 10(2) ppb. The analytical sensitivity, precision and stability of degrading products of acid degradation are satisfactory, which has been used for the determination of the trace piperacillin in human serum and urine with satisfactory results.     

Innovative mixture of salts in the quick,easy, cheap,effective, rugged,and safe method for the extraction of residual macrolides in milk followed by analysis with liquid chromatography and tandem mass spectrometry

A simple extraction technique has been developed for seven macrolide antibiotics in milk. The procedure involves a modified quick, easy, cheap, effective, rugged, and safe method based on acetonitrile extraction, followed by the addition of a mixture of salts (sodium sulfate, sodium chloride, and potassium carbonate) not yet reported in literature. The method was validated for tylosin and was selective, free of matrix effect, and linear in the range of 0.78–18.75 ng/mL in the final extract, corresponding to 0.125–3 times the maximum residue limit. The limit of detection, limit of quantification, decision limit, and detection capability were, respectively, 0.84, 2.79, 58.4, and 71.7 μg/kg. The overall average recovery at 25, 50, and 75 μg/kg ranged from 89–97%. Repeatability and intermediate precision expressed by relative standard deviations were below 10.5 and 12%, respectively. The extension of the validation for spiramycin, throleandomycin, oleandomycin, roxithromycin, erythromycin, and clarithromycin is under consideration since the procedure proved to be able to efficiently extract all studied macrolides, with recoveries from 74–104% at 50 μg/kg for tylosin, erythromycin, spiramycin, and oleandomycin and 20 μg/kg for throleandomycin, roxithromycin, and clarithromycin.     

Carbamazepine: Stability Indicating HPLC Assay Method

Abstract

The present research work discusses the development of a stability indicating HPLC assay method for Carbamazepine as a bulk drug and from formulations. The mobile phase selected was acetonitrile, methanol, and water (10:60:40 v/v/v, respectively. The calibration curve of the drug was linear in the range of 1.0–20 µg/ml. The system precision and the method precision studies were carried out with an RSD of 0.969 and 1.40, respectively. The limit of detection and quantitation were 85.5 and 285 ng, respectively. The mean percent recovery was found to be 100.22%. The developed assay method was found to be accurate, precise and specific.     

Determination of guaiphenesin and sodium benzoate in Liqufruta garlic cough medicine by high performance liquid chromatography

A new and simple isocratic high-performance liquid chromatographic method with ultraviolet detection is described for simultaneous determination of active guaiphenesin and preservative sodium benzoate in Liqufruta garlic cough medicine formulation. The chromatographic separation was achieved using a Zorbax CN; 150 mm × 4.6 mm and 5 μm particle size column employing acetonitrile and water (20: 80, v/v) containing 0.1% formic acid (pH 3.5 ± 0.05) as the mobile phase. The method was validated with respect to linearity, range, precision, accuracy, specificity, limit of detection and limit of quantitation. The both analytes were detected by UV-Vis detector at 245 nm. The method was linear over the concentration range of 0.2–0.8 mg/mL and 0.02–0.06 mg/mL for guaiphenesin and sodium benzoate, respectively. The limit of detection was found to be 0.14 μg/mL for GP and 0.06 μg/mL for SB and the quantification limit was 0.54 μg/mL for GP and 0.22 for SB. Accuracy, evaluated as recovery, was in the range of 97.8–100.0%. Intra-day precision and intermediate precision showed relative standard deviation <1% in each case.     

Spectrophotometric method for quantitative determination of montelukast in bulk,pharmaceutical formulations and human serum

A simple ultraviolet spectrophotometric method for the estimation of montelukast in methanol has been devised and been compared with the existing pharmacopoeial RP-HPLC method for estimation of the drug. The limit of detection of montelukast at 283 nm was 75.2 ng/mL. The calibration was linear in the range of 3–45 μg/mL. Analytical parameters such as stability, selectivity, accuracy and precision have been established for the method in MONAKA® tablets and in human serum and evaluated statistically to assess the application of the method. The method was validated under the ICH and USP guidelines and found to comprise the advantages for simplicity, stability, sensitivity, reproducibility and accuracy for using as an alternate to the existing non-spectrophotometric methods for the routine analysis of the drug in pharmaceutical formulations and in pharmaceutical investigations involving montelukast.     

HPLC-UV analytical method for determination of pizotifen after in vitro transdermal diffusion studies

Pizotifen malate is an antihistamine and serotonin inhibitor used in the preventive treatment of migraine and eating disorders. A simple, rapid, accurate and precise high‐performance liquid chromatography (HPLC) method involving ultraviolet detection was validated for the quantitative analysis of pizotifen malate in samples from in vitro transdermal diffusion studies. The method was validated for specificity, linearity, accuracy, precision, limit of detection, limit of quantification and robustness. Drug stability in the solution was also determined under different conditions. Separation was carried out using a 250 × 4.0 mm Kromasil^® C₁₈ column at room temperature. The detector response, fitted at 254 nm, was found to be linear in a concentration range between 0.24 and 24.0 µg/mL. The limit of detection was 0.02 µg/mL and the limit of quantification was 0.07 µg/mL. Finally, in vitro transdermal diffusion of pizotifen malate was characterized using the validated HPLC method. Copyright © 2011 John Wiley & Sons, Ltd.