铅是一种危害人体神经、血液、骨骼、消化、生殖等系统的重金属元素,被国际癌症组织划定为致癌物之一。尤其对儿童危害巨大,儿童对铅的吸收率是成年人的8倍,排除率不及1/30,铅毒严重影响儿童智力及体格发育。
日前,多家卫浴品牌被曝水龙头铅含量超标。美国颁布无铅法案,规定龙头含铅量不得超过0.25%,欧美国家也积极制定相关法案。据有关行业人士称,中国也将出台国标,对龙头中铅含量做出严格限定。因此,需要加强对金属中铅含量的测定。我们采用原子吸收分光光度法对锌中的铅含量进行了测定,得到标准曲线的相关系数R2=0.9999。
含铅水龙头的使用势必对饮用水造成二次污染,吸收进入人体则产生巨大危害。我国国标《GB 5749-2006 生活饮用水卫生标准》规定饮用水中铅含量应低于10μg/L,因此饮用水中铅的测定同样需要加强。
我们参考国标《GB/T 5750.6-2006 生活饮用水标准检验方法 金属指标》采用原子吸收分光光度法对河水及牛奶中的铅含量进行了测定,可以检测到铅的浓度为1.35μg/L,完全满足国标规定的限量值。
Hitachi High-Technologies Corporation ZA3000 Sample Pb concentration(ug/L) Recovery rate(%) by only diluting with purified water. Milk contains protein, fat, etc. and the stability of the measured values is affected by foams generated during the sample drying stage. By using the specially designed twin cuvette (Pyro D HR), a sample is injected into two different injection ports. Therefore, the size of the liquid droplet is reduced to a half compared to the size when injected in only one port while the amount of the sample injected is the same, resulting in the reduced effect by foaming during the drying. As a result, the analysis with a good reproducibility is possible. Milk 1.30 Milk + Pb 5 pg/L 6.35 101 Element : Pb Instrument :ZA3000 Atomization : GA Wavelength : 283.3 nm Lamp Current : 7.5 mA Slit Width : 1.3nm Cuvette : Pyro D HR Meas. Mode : Working Curve Signal Mode : BKG Corrected Curve Order : Linear Calculation : Peak Area Time Constantt: 0.1 sec Temp. Control :ON Sample Volume :20 uLAddition: Speed:4 MATRIX MODIFIER Matrix Modifier : 1000 mg/L Pd+MgVolume : 10 uL Order: After TEMPERATURE PROGRAM NOTE Stage Initial/Final Heating/Keeping Gas Flow Rate Gas Temperature (C) (Sec) (mL/min) 2 Incineration 1 Drying 50/90 60 / 0 20090/300 20/0 200800/800 20/0 3 Atomization 2000/2000 0/3 2000 NormalNormalNormalNormal 4 Cleaning 2800/2800 0/4 200 Normal The specially designed twin injectioncuvette, Pyro D HR, was used for themeasurement. The sample diluted to1/5 with purified water was used for the measurement. CONC (ug/L) Mean ABS SD RSD REF ABS STD 1 0.00 0.0017 0.0006 35.29% 0.20180.025 STD 2 1.00 0.0049 0.0001 2.04% 0.1891 STD 3 3.00 0.0116 0.0004 3.45% 0.1902 3 STD 4 5.00 0.0185 0.0001 0.54% 0.18510.01·一 1 0.26 0.0025 0.0001 4.00% 0.2854 1 0.26×5=1.30 pg/L 0R2: 0.9999 1+ Pb 5ug/L 1.27 0.0059 0.0001 1.69% 0.2822 0.00 1.27×5=6.35 pg/L 0 3 KEY WORDS Atomic Absorption Photometer Bio/Medical Science/Food/Pharmaceutical, Food, Food Chemistry, (AA) Food Component, Milk, Lead, Pb, Flameless, Graphite Furnace, AA, ZA3000, GA, Pyro D HR, Food Sheet No. AA120012-00
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日立科学仪器(北京)有限公司为您提供《牛奶中铅检测方案(原子吸收光谱)》,该方案主要用于液体乳中重金属检测,参考标准--,《牛奶中铅检测方案(原子吸收光谱)》用到的仪器有日立ZA3000系列原子吸收分光光度计