微波消解-电感耦合等离子体质谱法测定大米中铅、镉、砷、汞、铬含量

目的 建立微波消解—电感耦合等离子体质谱法(ICP-MS)同时测定大米中铅、镉、砷、汞、铬含量,为新标准《食品安全国家标准食品中污染物限量》的实施提供方法参考。方法 样品经硝酸与微波消解处理,优化的ICP-MS条件,采用在线引入内标,对大米中5种重金属进行检测,同时用大米粉国家标准物质GBW(E)100349a对方法准确度、精密度进行验证。结果 通过对大米粉标准物质分析,所测的5种重金属元素测定值均在参考值范围内,大米样品3水平加标回收率为82%～108%,RSD为2.8%～7.5%。结论 根据国标GB 2762—2022规定的大米中5种重金属限值标准,本实验所测大米样品均未超过限值,合格率100.0%。该方法检测效率高,检出限低,检测结果快速、准确,适合大米中5种重金属元素同时分析测试。     

湿式消解法测定茶叶中铜、铅、锌、铁含量

[目的]探索湿式消解法在测定茶叶中铜、铅、锌、铁等元素样品前处理上的应用.[方法]样品经加混合酸在电热板上加热消解彻底后,用火焰原子吸收光谱法同时测定铜、铅、锌、铁等元素的含量.[结果]各元素标准曲线线性好,r值为0.998 0～1.000 0.相对标准偏差为0.96%～4.09%,回收率为95.42%～101.83%,标准样品的实际测定值与标准参考值相吻合.[结论]通过湿式消解法一次性处理样品,能同时测定多种元素,其方法简单、便捷,准确度和精密度都符合实验要求.     

食品中金属元素砷、镉、铅等ICP-MS法的测定

目的在新购进的ICAP-Q仪器上建立应用ICP-MS法同时测定食品中多种金属元素的方法,并对新实施的GB 5009.268-2016(ICP-MS法)进行验证。方法大米、茶叶经微波消解处理后,用ICP-MS法KED模式测定其钒、镍、铬、砷、镉、铅、硒等重金属元素的含量,测定其标准曲线、检出限、加标回收率和标准样品加以验证。结果各元素标准曲线相关系数在0.999 7～1.000 0之间,精密度在0.6%～4.6%之间,加标回收率在0.6%～4.6%之间,检出限均低于GB 5009.268-2016(ICP-MS法)、大米GBW 10045和茶叶GBW 10052标准物质其测定元素结果与标准值一致。结论 ICP-MS法适用于食品中多种重金属元素同时测定,该法操作简便快速,精密度和准确度好。     

微波消解ICP-MS测定粮食、蔬菜中8种元素

目的建立电感耦合等离子体质谱(ICP-MS)测定粮食、蔬菜中8种元素的方法。方法样品在硝酸介质中经微波消解,消解液用ICP-MS同时测定粮食、蔬菜中Al、As、Cd、Cu、Pb、Zn、Fe和Ca等8种元素的含量。结果用ICP-MS法测定了国家标准参考物质贻贝(GBW08571)和小麦粉(GBW08503B),其测定值在标准参考值范围内,方法的准确度在79.4%~111.5%,相对标准偏差为1.1%~6.6%。样品加标回收率为93.5%~110%。分析中采用了内标校正和稀释样品的方法,有效地校正了基体干扰。结论微波消解ICP-MS方法简便、快速、准确、可靠,适于食品中多元素同时测定。     

ICP-MS法同时测定生活饮用水中铝、锰、铁等14种元素

目的建立生活饮用水中铝、锰、铁等14种元素同时测定的ICP-MS方法。方法 Agilent 7 900电感耦合等离子体质谱仪优化后用混合内标校正基体干扰和漂移,标准曲线法定量,对经过前处理的生活饮用水样品中铝、锰、铁、镍、铜、锌、砷、硒、银、镉、钡、汞、铊、铅共14种元素进行同时测定。结果 14种待测元素线性良好,相关系数0. 999 5,检出限在0.001 438～0.208 8μg/L之间,均低于国家饮用水卫生标准对各元素的标准限值;平行测定两种不同浓度的标准溶液、一份生活饮用水样品及其高、低加标样品中各元素11次,其测定值的相对标准偏差为0.234%～3.72%,加标回收率为90.1%～108.8%。结论该方法高效简便、线性范围宽,结果令人满意,是一种适用于生活饮用水中多种元素同时分析的检测方法。     

等离子体原子发射光谱同时测定中成药金水清中多种微量元素

提出了中成药金水清中多种微量元素的等离子体原子发射光谱 ( ICP- AES)同时测定的方法 ,并以 GBN80 50 1桃叶标准样进行对照测定 ,标准样的测定值与参考值吻合较好。该方法具有灵敏、准确、操作简便及多元素同时测定等优点 ,适应于中成药及其剂型中多种微量元素的同时测定。     

测试条件对土壤中33种元素同时测定的影响

目的采用了电感耦合等离子质谱法(ICP-MS)测定土壤中33种元素的方法。方法本文通过优化电感耦合等离子质谱法(ICP-MS)的工作条件,测定土壤的多种元素的质量,最后实验得出土壤中元素分析的最佳优化参数。结果 33种元素的浓度为0.00μg/L～500.00μg/L时,线性关系良好,相关系数(r)均0.999,仪器的检查限为0.000 40μg/L～0.081μg/L。33种元素的加标回收率为90.00%～101.00%,相对标准偏差(RSD)0.13%～7.2%。测定国家标准物质GBW07426(GSS-12),测定值均在参考值不确定度范围内。结论该方法处理土壤样品简单、快速,检测准确、灵敏度高,适用于土壤中多种元素的测定。     

白兰地酒中铅、铜、铁、锰同时测定的电感耦合等离子体质谱测定法

目前 ,测定白兰地酒中的微量元素多采用比色法和原子吸收法等技术 ,但比色法消耗试剂多 ,操作繁琐 ;原子吸收法的基体干扰较严重 ,且必须逐个元素测定 ,检验周期长。电感耦合等离子体质谱法 (ICP -MS法 ) [1] 具有灵敏度高 ,精密度好 ,线性范围宽 ,可同时测定多种元素等优点 ,已广泛应用于多种样品微量元素的分析。由于白兰地酒中微量元素的含量较低 ,基体较复杂 ,为此 ,本文针对白兰地酒的特点 ,用ICP -MS技术 ,建立了一种适合白兰地酒中铅、铜、铁、锰同时测定的ICP -MS方法。1　实验部分1 1　试剂　硝酸为mos级 ,水为 18 2MΩcm的…     

微波消解ICP-MS同时测定海产品及禽畜内脏中14种元素的方法改进及应用

目的 通过优化微波消解和空白实验，解决国家标准方法对生物样品消解不彻底的问题，建立海产品及禽畜内脏中铝、锰、铜、钡、铬、钒、镉、铅、硒、锑、镍、锡、砷、锂14种元素同时测定的分析方法。方法 采用大虾、扇贝、猪肝等标准参考物质作为样品，同时用国家标准消解方法和优化后的消解方法进行前处理，电感耦合等离子体质谱法测定14种元素，对优化后的方法的线性，精密度、检出限、加标回收进行试验并将此方法应用于实样测定。结果 方法检出限为0.001 mg/kg～0.08 mg/kg,定量限为0.003 mg/kg～0.3 mg/kg,线性范围为0.5μg/L～500μg/L,RSD≤4.8%,加标回收率为90.3%～109.6%,采用优化后的方法测定标准参考物质，其回收率高于国家标准方法。结论 经优化后的检测方法相比于国家标准更准确，且快速、灵敏，适用于海产品及禽畜内脏中的多元素同时分析。     

低温压力消解罐法测定食品中汞

由于汞在常温下具有发生氧化的独特性质,因此在检测食品中汞时必须处在硝酸等氧化状态和具备水冷凝装置,单独测定。监测污染物样品都要求汞、铅、镉等同时测定,现行国家标准方法测定3种元素前处理得需用3种不同方法,这既增加工作量和时间,也消耗试剂与器材。基于国内已开展用压力消解罐测定食品中Pb、Cd等元素,我们用该方法对食品中汞进行了测定。1 材料与方法1.1 试剂和器材硝酸、硫酸、过氧化氢、氯化亚     

水浴酸消化-电感耦合等离子质谱同时测定全血中多种元素的分析方法研究

目的建立电感耦合等离子体质谱（ICP—MS）同时测定全血中多种微量和痕量金属元素的分析方法,为开展重金属污染对人体健康的影响研究提供检测手段。方法样品经硝酸水浴消化后,以钪、锗、铑和铼作为在线内标,内标中加入异丙醇进行基体匹配,用ICP-MS测定铅、镉、砷、汞、铬、硒、锑、钴、钼、铊、锰、铜、铋、锌、铁、钙及镁等17种元素,采用全血标准物质-Seronorm^TM TraceElementsWholeBloodL-1及L-2实施质量控制。结果各金属元素线性相关系数均大于0．9995;重金属元素检出限铅、锑为2．0μg／L,铬、锰为1．0μg／L,铜为5．0Ixg／L,其他元素均在0．008～0．3μg／L之间;对标准物质7次测定结果均在标准值范围内,其相对标准偏差小于10％;在连续20h测定400份血样过程中,对同一样品间隔重复测定16次,其相对标准偏差小于10％。结论水浴酸消化一电感耦合等离子体质谱方法操作简便、灵敏度高、稳定、抗干扰性强,适用于大批量血样中多种重金属及营养元素的同时测定。     

微波消解-电感耦合等离子体质谱(ICP - MS)法同时测定茶叶中25种元素

目的 建立同时测定茶叶中25种元素的微波消解 - 电感耦合等离子体质谱法,为茶叶质量监管提供技术支持。方法 以6种市售茶叶为样品,样品经微波消解后,利用ICP - MS同时测定茶叶中25种元素,以同位素内标法定量。结果 实验表明,K、Ca、Na、Mg、Fe的线性范围为 0～50 000 μg/L; Hg的线性范围为0～2 μg/L;其余元素的线性范围为0～1 000 μg/L;,相关系数均大于0.9 995;检出限为0.001mg/kg～0.800 mg/kg;回收率为96.7%～106.6%;相对标准偏差为0.66%～5.68%。结论 本方法快速、准确、灵敏,适用于批量茶叶中多元素的同时测定。     

AES法检测营养品中的微量元素

目的 :用原子发谢光谱分析法 ( AES)检测营养品中的微量元素。方法 :用平面光栅摄谱仪拍摄未知样品之原子发射光谱图 ,并作定量分析。结果 :测定营养品中微量元素的含量。结论 :与仪器昂贵、操作复杂的其它方法比较 ,本法具有方便、简单、可同时测定多种元素等优点     

Evaluation of microwave-assisted ultraviolet digestion method for rice and wheat for subsequent spectrometric determination of As,Cd, Hg and Pb

The aim of this study was to optimize a sample preparation method for rice and wheat using microwave-assisted ultraviolet digestion (MW-UV) for subsequent determination of toxic elements. Cadmium and Pb were determined by sector-field inductively coupled plasma mass spectrometry (SF-ICP-MS), while As and Hg were determined by chemical vapor generation coupled to atomic absorption spectrometry (CVG-AAS). A systematic evaluation of the microwave heating program, nitric acid concentrationand sample mass was performed to optimize the MW-UV digestion method for rice and wheat samples. The relationship between nitric acid concentration and sample mass was monitored by determination of the residual carbon content (RCC) and residual acidity (RA) in order to obtain a high efficiency of digestion. The MW-UV method was successful at digesting up to 1100 mg of rice and wheat using 4 mol L⁻¹ HNO₃ with RCC and RA lower than 1.5 %, and 10 %, respectively. Recovery results ranging from 88 % to 117 % and agreement with certified reference values (t-test, 95 % confidence level) were obtained after digestion using the MW-UV method for spiked samples and certified reference materials (peach leaves-NIST 1547 and tomato leaves-NIST 1573), respectively. The optimized method was suitable for analysis of toxic elements in rice and wheat in compliance with the maximum levels reported in official directives.     

高盐食品中铅的石墨炉原子吸收光谱测定法

目的建立一种石墨炉原子吸收光谱法测定高盐食品中铅的实验方法。方法使用氯化钯-磷酸二氢铵混合基体改进剂提高灰化温度,并结合标准加入法,消除高盐食品的基体干扰。对实验条件进行优化比较,并对氯化钠的干扰影响、方法检出限、回收率、精密度及有证标准物质的分析结果进行考查。结果该方法可消除样液中5%以内氯化钠造成的基体干扰。方法检出限为0.024 mg/kg,精密度为4.5%～5.6%,回收率为94.0%～108.0%,标准物质的分析结果在证书值范围内。结论该方法能有效消除高盐基体的干扰,并具有良好的精密度和准确度。     

流动注射和连续流动分析技术测定饮用水及水源水中氨氮的可靠性分析

目的 采用流动注射法和连续流动法测定饮用水及水源水中氨氮,并对相关技术参数进行评价,分析两种技术在饮用水及水源水氨氮测定中的可靠性.方法 分别采用流动注射仪和连续流动仪测定饮用水及水源水中氨氮,对测量范围、最低检测质量浓度、精密度、加标回收率等相关参数进行评价;与现行国标方法进行实际水样的测定结果比对;同时,对相关干扰...     

Single laboratory validation of an optical biosensor method for the determination of folate in foods

The scope of a recently developed optical biosensor platform for application to milk products was extended in this study to the determination of folate in supplemented and non-supplemented foods. The technique utilises folate-binding protein within an automated high throughput inhibition assay format and was subjected to single-laboratory validation. Critical performance factors were evaluated, including establishing four-parameter logistic calibration parameters, confirmation of equivalent molar cross-reactivity as a function of poly-γ-glutamate chain length, demonstration of analytically insignificant non-specific binding, and verification of the absence of food-derived matrix interferences. A panel of certified reference food materials was used to estimate assay precision (HorRat_r: 0.3–0.8), confirm recovery within accepted guidelines (72–112%) and establish method accuracy based on data compliance with assigned folate values. The optimised method was applied to a range of food items (milk, cereal, flour, broccoli, egg, fishmeal, liver) and the influence of assay variables including preheat and trienzyme treatments was demonstrated to be minor. The described assay is an expedient alternative to current methods used for the determination of the folate content in foods.     

Quantitative evaluation of selenium contained in tea by high performance liquid chromatography

For determination of selenium (Se) in biological materials, an improved method based on high performance liquid chromatographic determination of the fluorophore formed by reaction of selenite with 2,3-diaminonapththalene was developed. The concentration detection limits were 0.5 ng/g in dried materials and 0.03 ng/mL in fluid materials. In quadruplicate assays of 11 biological reference materials using the proposed method, measured Se concentrations were not significantly different from their certified values. Thus, the proposed method is reliable and suitable for the determination of trace levels of Se in foods. Using the proposed method, Se concentrations in various kinds of tea were determined to assess the contribution of tea to daily Se intake in the Japanese population. Se concentration in the leaves of general black, green and oolong tea obtained in local retail stores was 33 +/- 19 ng/g (n=440). The leaves of a particular Chinese green tea sold under the name "high Se tea" were found to contain 455 +/- 184 ng/g (n= 14) of Se. While the percentage of Se extractable by infusion was less than 5% for the general teas, that in the high Se tea was more than 20%. These results indicated that intake of tea does not contribute to daily Se intake in the Japanese population. However, since infusions from high Se tea contained over 5 ng/mL of Se, consumption of over 1 L/d of tea derived from such high Se teas may increase the daily Se intake by close to 10%.     

Quantitation of urinary metabolites of toluene,xylene, styrene,ethylbenzene, benzene and phenol by automated high performance liquid chromatography

Summary An automated high performance liquid chromatographic method (HPLC) for the direct determination of urinary concentrations of hippuric acid (HA), and o-, m- and p-methyl hippuric acids (MHAs), metabolites of toluene and o-, m-, and p-xylenes, and of urinary phenyl glyoxylic acid (PGA) and mandelic acid (MA), metabolites of styrene or ethylbenzene, is described. Methanol was added to urine, the mixture was centrifuged and the supernatant was injected into HPLC. A stainless-steel column packed with octadecyl silanized silicate was used and the mobile phase was a mixed solution of 5 mM potassium phosphate monobasic/acetonitrile (90/10). The method is simple and specific. Urine can be analyzed without solvent extraction. Analysis can be performed satisfactorily within 45 min for samples containing HA, MHAs, PGA and MA, and within 15 min for those containing HA, PGA and MA. Another automated HPLC method for the determination of urinary concentrations of phenylsulfate (PhS) and phenylglucuronide (PhG), metabolites of benzene and phenol, is also described. Urine was centrifuged and the supernatant was injected into HPLC. A column packed with octadecyl silicate and a mobile phase of 50 mM of potassium phosphate monobasic/acetonitrile (85/15) were used. The whole analyses and quantitative determination can be performed within 15 min for samples containing PhS and PhG in the worker's urine with a simple mobile phase. The accuracy and precision in the present methods by the use of automated HPLC were satisfactory.     

Health Evaluation of Volatile Organic Compound (VOC) Emissions from Wood and Wood-Based Materials

In this study, the authors describe a method for evaluation of material emissions. The study was based on chemical analysis of emissions from 23 materials representing solid wood and wood-based materials commonly used in furniture, interior furnishings and building products in Denmark in the 1990s. The authors used the emission chamber testing method to examine the selected materials with a qualitative screening and quantitative determination of volatile organic compounds. The authors evaluated the toxicological effects of all substances identified with chamber testing. Lowest concentration of interest and standard room concentrations were assessed and the authors calculated an S-value for each wood and wood-based material. The authors identified 144 different chemical substances with the screening analyses and a total of 84 individual substances were quantified with chamber measurements. The irritative effects dominated at low exposure levels; therefore, the lowest concentration of interest and the S-value were based predominantly on these effects. The S-values were very low for solid ash, oak and beech. For solid spruce and pine, the determining substances for size of the S-value were Δ³-carene, α-pinene and limonene. For the surface-treated wood materials, the S-value reflected the emitted substances from the surface treatment.