|Emmanuel with 'A Practical Guide to ICP-MS'.|
When using FAAS there are concerns about safety aspects because of the use of acetylene and nitrous oxide. The major concerns cover a wide range; from storage and handling of cylinders, to the use of the flame in the instrument. Presence of a naked flame is of a concern in laboratories especially those that handle organics, which are highly flammable, for this reason FAAS have to be attended to all the time. All these issues are eliminated with the use of 4210 MP-AES.
Improved analytical performance comes about because there is an improvement of in detection limits for MP-AES compared to FAAS. In the case of some elements such as Ca and V this can be an order of magnitude lower. An improvement in detection limits implies that it is possible to analyse elements that otherwise have high detection limits in FAAS like phosphorus and boron. In other words, elements that cannot be analysed on FAAS are easily analysed on the MP-AES. It can also analyse up to 10 minutes at a time using the same sample volume as an FAAS. Selenium can be measured using hydride generation within the same analytical run as other samples. The higher temperature of nitrogen plasma atomisation /ionisation also improves the linear range and stability compared to FAAS.
When it comes to ease of use in MP-AES, this results from the fact that with the hotter plasma source of 4210 MP-AES, chemical interferences that are encountered in FAAS are eliminated. This means that the element specific sample preparation required on FAAS is not needed which greatly simplifies the sample preparation process.
Change from FAAS to MP-AES
With the benefits highlighted above, I look forward to moving from using the FAAS to using the MP AES. The challenge that awaits me on my return to Malawi, is to prepare the laboratory building services in time for delivery of the instrument, which promises to vastly improve our current capability for elemental analyses, whilst keeping costs down. I won’t be alone in this challenge, partners on the Royal Society-DFID project will also be receiving an MP-AES in Zambia and Zimbabwe in February to March and we will share the training experience through collaboration and regular interaction, with support from the sales company (Chemetrix) in South Africa and colleagues from the Centre for Environmental Geochemistry (BGS-University of Nottingham).
Many thanks to Agilent and Reading Scientific Services for hosting the demonstration of the MP-AES. Thanks also to Robert Thomas who donated 50 of his textbooks ‘Practical Guide to ICP-MS – a tutorial for beginners’. These textbooks will be given to students and technicians within the Royal Society-DFID network, as well as other partner organisations in Africa.