PDF《石墨炉原子吸收》

3 标准和样品的制备 PerkinElmer公司用于铅、 镉和砷测定的单元素标准物 质(序列货号分别为As: N9300180;

Pb: N9300175;

Cd: N9300176;

)作为标准储备液用来制备工作曲线同时用 作质量控制检查标准.所有标准的制备都使用异丙醇 (VWR, normapur试剂级) 按照体积比(v/v)稀释. 所有元 素都使用1000 mg/L Pd 和100mg/L Mg的混合溶液作 为化学改进剂. 这种化学改进剂制备如下: 称量0.1430克 乙酰丙酮钯 (Ⅱ价钯) (奥德里奇, 99%, 兆MW=304.62) , 移取1mL镁的油标准 (conostan, 5000μg/mL) , 将它们溶 于50mL二甲苯 (panreac, 试 剂级) 溶液中. 5种食用油 (棕榈, 芝麻, 向日葵, 大豆和米糠) 均从当地的超市购买, 且没 有做任何预处理. 所有的食用油样品均小心的在聚丙烯瓶( 货号: B0193234)中用异丙醇稀释20倍 (体积比) .

3 Standards and Sample Preparation Single-element PerkinElmer Pure Calibration Standards (Part Nos. As: N9300180;

Pb: N9300175;

Cd: N9300176) were used as the stock standards for preparing working standards and quality control check standards. All standards were prepared with IPA (VWR, Normapur Reagent grade) by volume/volume (v/v) dilution. A mixture of

1000 mg/L Pd and

100 mg/L Mg was used as the chemical modifier for all elements. The chemical modifier was prepared by weighing 0.1430 g of Pd(II) acetylacetonate (Aldrich, 99%, MW=304.62) and pipetting

1 mL of Mg oil standard (Conostan,

5000 ?g/mL) and dissolving with

50 mL of xylene (Panreac, reagent grade). Five edible oils (palm, sesame, sunflower, soybean and rice bran) were purchased from a local supermarket and were used without any pre-treatment. All oil sam........