1.关于元素标液的选择:
AAS标液还是
ICP-MS标液?
AAS、HG
AAS、AFS推荐使用
AAS标液,价格便宜,ICP-OES/AES、
ICP-MS推荐使用
ICP-MS标液,同时
ICP-MS标液 >
AAS标液,
ICP-MS标液可以替代
AAS标液,但
AAS标液不建议用在ICP分析上。为什么要这样选择?
AAS标液与
ICP-MS标液有什么区别?
1.
AAS与ICP分析仪器之间的区别?
a.检测原理不同
AAS 不同元素会吸收不同波长的光
ICP 不同元素会发射不同波长的光
b.单次检测元素数量不同
AAS 1
ICP 70
c.仪器检测灵敏度不同
AAS 50-5000ppb
HG
AAS 0.1-50ppb
ICP-AES/ICP-OES 1-100ppb
ICP-MS 0.001-5ppb
2.
AAS标液与
ICP-MS标液之间的区别?
a.用于配置标液的起始物质starting material选择不同:
AAS通常选择产品纯度在99.0%以上的优级纯的无机盐或者金属氧化物,剩余1%的杂质会带入其他元素杂质;
ICP-MS则选择纯度在99.99%甚至更高的无机盐或者金属氧化物;
b.基质matrix的选择不同
AAS标液通常选择ppm级别的优级纯酸,部分厂商也会选择用高级别的重蒸酸;
ICP-MS标液通常选择ppt级别的超纯酸;
结论:
AAS元素分析灵敏度较ICP差,ICP受背景元素杂质干扰,所以
ICP-MS应选择
ICP-MS标液,在样品前处理用酸以及元素稀释上,ICP-AES/OES应选择ppb级别的超纯酸,
ICP-MS应选择ppt级别的酸。
下面是国外专业元素标液生产商的回复,大家可以分享一下:
1°The difference between
AAS standards and ICP-OES/MS standards is the starting material.
AAS standards are typically made from ACS grade salts. This means the purity of the material is about 99%. The other 1% of the material can be trace amounts of other metals. The ICP-OES/MS standards are made from high purity metals salts or oxides typically 99.99% or better. This limits the amount of trace metals in a standard. AA does not have enough sensitivity to detect the impurities, ICP-OES/MS do. If your customer was to buy some AA single element standards and combine them to make a mix, they may issues if they use an ICP-OES/MS instrument.
2°There are different grade acids used for different techniques.
AAS standard only need ACS grade acids. While some ICP-OES can use ACS Grade Acids the detection limits for ICP-OES instruments has improved greatly over the past 20 years. Because of this improvement I recommend that a company using ICP-OES should use the Trace metal grade acids and the ICP standards. For
ICP-MS work only use the highest purity acids and standards available.