石墨炉原子吸收法测定食品包装物中锑浸出量

建立了测定食品包装中锑浸出量的石墨炉原子吸收光谱法。将食品包装物的4％乙酸浸泡液在酸性条件下用碘化钾还原,再以吡咯烷二硫代氨基甲酸铵（APDC）作为螯合剂萃取后,用石墨炉原子吸收法测定样品锑含量,对石墨炉的升温程序,特别是灰化温度和原子化温度做了试验并对相关条件予以优化,结果表明：在所测得的吸光度与锑的质量浓度25μg/L以内呈线性关系,方法检出限为2．1μg／L,加标回收率为94．2％～99．1％。     

原子吸收光谱法测定钨合金中痕量铁

钨合金试样中含有钨、铁、锰等元素,将钨合金试样经盐酸-硝酸在加热的条件下滴加氢氟酸溶解后,加入锶盐以消除其他元素对铁的干扰,采用原子吸收分光光度法对其中铁元素含量进行了测定。结果显示,微量铁的质量百分含量为0.3341%,其RSD为2.1976%,加标回收率为97%~101%。该方法测定速度快,灵敏度高,干扰小,结果准确可靠。     

连续光源原子吸收光谱法同时测定镍基溶液中微量铁、钴、铅、锌含量

本文探讨镍基体对待测元素铁、钴、铅、锌干扰情况,采用标准加入校正法消除基体干扰影响,拟定试验条件,建立连续光源原子吸收光谱法对镍系统溶液中微量元素的测定方法,实现一次进样连续测量Fe、Co、Pb、Zn,此方法简单、快速、准确、可靠。     

Comparison of four analytical techniques based on atomic spectrometry for the determination of total tin in canned foodstuffs

Different techniques for the determination of total tin in beverages and canned foods by atomic spectrometry were compared. The performance characteristics of inductively coupled plasma-mass spectrometry (ICP-MS), hydride generation-inductively coupled plasma-atomic emission spectrometry (HG-ICP-AES), electrothermal atomisation-atomic absorption spectrometry (ETA-AAS) and inductively coupled plasma-atomic emission spectrometry (ICP-AES) were determined in terms of linearity, precision, recovery, limit of detection, decision limit (CCα) and detection capability (CCβ) (Decision 2002/657/EC). Calibration ranges were covered from ng?l^?1 to mg?l^?1 level. Limits of detection that ranged from 0.01, 0.05, 2.0 to 200?µg?l^?1 were reached for ICP-MS; HG-ICP-AES; ETA-AAS and ICP-AES, respectively. Precision, calculated according to ISO 5725-2 for repeatability and within-laboratory reproducibility and expressed as relative standard deviation (RSD), ranged from 1.6% to 4.9%; and recovery, based on Decision 2002/657/EC, was found to be between 95% and 110%. Procedures for the mineralisation or extraction of total tin were compared. Wet digestion, sequentially, with nitric acid and hydrogen peroxide provided the best results. The influence of possible interferences present in canned food and beverage was studied, but no interference in the determination of tin was observed. Since maximum levels for tin established by European Union legislation vary from 50?mg?kg^?1 in canned baby foods and infant foods up to 200?mg?kg^?1 in canned food, ICP-AES was chosen as the preferred technique for routine analysis thanks to its good precision, reliability and ease of use. The accuracy of this routine method was confirmed by participation in six proficiency test schemes with z-scores ranging from ?1.9 to 0.6. Several canned foodstuffs and beverage samples from a local market were analysed with this technique.     

Nitrate and nitrite content in organically cultivated vegetables

The nitrate and nitrite content of leaf vegetables (Swiss chard, sea beet, spinach and cabbage), “inflorescence” vegetables (cauliflower) and fruit vegetables (eggplant and vegetable marrow) grown with organic fertilizers have been determined by a modified cadmium–Griess method. Samples were purchased from organic food stores as well as collected directly from an organic farm in Madrid (Spain). Nitrate levels were much higher in the leaf vegetables (especially Swiss chard species; average over the different samples and species of 2778.6 ± 1474.7 mg kg^{? 1}) than in inflorescence or fruit products (mean values between 50.2 ± 52.6 and 183.9 ± 233.6 mg kg^{? 1}). Following Swiss chard species, spinach (1349.8 ± 1045.5 mg kg^{? 1}) showed the highest nitrate content, and nitrite was found above the limit of detection in some samples only (spinach, 4.6 ± 1.0 mg kg^{? 1}; sea beet, 4.2 ± 0.7 mg kg^{? 1} and Swiss chard, 1.2 ± 0.4 mg kg^{? 1}). Some vegetables (spinach, cabbage and eggplant) had lower nitrate content in the samples harvested in summer, showing the influence of climatic conditions on the nitrate levels in a plant. The samples taken directly from the organic farm, with the exception of eggplant, had higher or slightly higher average nitrate values than samples purchased in the organic food stores, ranging from 117 to 1077%.     

原子吸收分光光度法测定中药材中重金属含量

采用火焰法、石墨炉法,样品消解后直接测定中药材丹参、白芍中重金属铜、铅、镉的含量。结果表明：重金属铜在0～0.8μg/mL、铅在0～80μg/L、镉在0～0.8μg/L范围线性关系良好,相关系数分别为0.995 6、0.996 3、0.999 4;丹参、白芍中所含铜、铅、镉均符合《中国药典》规定。本法简单、快速、灵敏,适用于中药材中微量重金属的测定,结果满意。     

Determination of Cd,Cu, and Pb after Cloud Point Extraction using Multielemental Sequential Determination by Thermospray Flame Furnace Atomic Absorption Spectrometry (TS‐FF‐AAS)

Abstract

In the present paper a procedure for simultaneous preconcentration of Cd, Cu, and Pb using cloud point extraction (CPE) and multielemental sequential determination by thermospray flame furnace atomic absorption spectrometry (TS‐FF‐AAS) is proposed. This preconcentration procedure is based on the metals extraction into micellar media of octylphenoxypolythoxyethanol (Triton X‐114) after their reaction with 1‐(2‐pyridylazo)‐2‐naphtol (PAN). A Box‐Behnken design was used to optimize the variables (pH, buffer concentration and volume of NaCl) involved in the extraction procedure. Enrichment factors were calculated as the ratio between the slopes of calibration equations with and without the preconcentration procedure in the TS‐FF‐AAS, with values of 59, 25, and 21 respectively for Cd, Cu, and Pb. Limits of detection (LOD) (3s_b, n=10) were also calculated as 0.025, 0.38, and 0.43 µg L^?1 to Cd, Cu, and Pb, respectively. The precision (repeatability) expressed as relative standard deviation (RSD, n=10) for reference standards of 10.0 and 20.0 µg L^?1 were 6.1 and 4.5% for Cd, 7.2 and 3.4% for Cu and 5.2 and 8.7% for Pb. The accuracy was confirmed through the analysis of certified reference material (NIST 1643d, Trace elements in water). The developed procedure was also applied to Cd, Cu, and Pb determinations in mineral water samples.     

原子吸收光谱法测定食品中重金属含量的研究进展

原子吸收光谱近年来被广泛用于食品中重金属含量的测定,该方法与传统化学分析方法相比具有灵敏度更高、测定结果更准确等优点。本文综述使用原子吸收法测定蔬菜、粮食、海产品和饮品中的铅(Pb)、镉(Cd)、铬(Cr)、汞(Hg)和砷(As)等重金属元素的研究进展。对使用火焰原子吸收(FAAS)、石墨炉原子吸收(GFAAS)和氢化物发生原子吸收(HGAAS)等方法测定不同元素的准确性、灵敏度和回收率等进行评述,并对原子吸收法在食品重金属检测中的应用进行展望。     

高盐食品中铅含量检测方法概述

综述了国内外高盐食品中铅含量检测的几种常见方法,如石墨炉原子吸收分光光度法(GFAAS)、火焰原子吸收分光光度法(FAAS)、电感耦合等离子体-质谱法(ICP-MS)、电感耦合等离子体-原子发射法(ICP-AES)、氢化物发生-原子荧光法(HGAFS)、氢化物发生-原子吸收分光光度法(HGAAS)、微分电位溶出法(DP-SA)等,综合探讨了各种方法的优缺点并展望了其发展前景,使之更好地指导并应用到实际检测工作中。     

原子吸收法测定金矿石中金的不确定度评定

针对原子吸收光谱法测定金矿石中金的测试过程, 详细分析了引入的不确定度来源。结果表明,测定结果的不确定度由标准液配制、样品制备、曲线拟合、样品均匀性以及检验重复性等引入的不确定度分量组成, 求得测量结果的标准不确定度和扩展不确定度分别为0.03 μg/g和0.06 μg/g。通过评定得出影响测量准确度的主要因素,需要在以后的工作中严格按照操作规程,不断提高分析测试质量和样品加工质量。