We're actually planning to acquire an ICP-OES for the analysis of metals in tap water, waste waters, sludges, and other environmental matrices. We're especially worried about the hydride-forming elements (Hg, Se, Sb, As). Is it possible to achieve sub-ppb LODs in these elements with ICP-OES and a hydride generator in tap water? I would appreciate "real-world" answers. The manufacturers all say "of course it is", but in the lab things often deviate from what they say.
Firstly, I work with ICP-OES for a three years. Secondly, I am analyzing hydride forming element (especially As) from the time to the time, while our tap water and well water have sufficiently enough As for a classic nebulization determination. Thirdly, yes it is possible to determinate sub ppb levels of those elements, BUT I was faced with some problems like, variation in blank due to contamination, difficulty with simultaneous determination of arsenic and antimony with mercury and selenium (Hg and Se is very easy reduced to elemental state in comparison to As and Se wich can reduce signal). As I mentioned , I don’t have too much experience, and I steel collecting “world wisdom”.
Dear Salvador: we measure Hg, Se, Sb and As simultaneously with a ICP-OES plus hydride generation in samples with a matrix very much complex than tap water and our LODS for Hg, Sb, and As were between 0,1 and 0,5 ppb. Se has a LOD of 1,0 ppb in our conditions.
Regards, Raúl
Thank you Raúl. Would you say that LODs are easy to achieve in routine or do they requiere demanding conditions and an experienced user supervising each analysis? In our lab we've working with GFAAS and Hydride FAAS - Cold Vapour AAS, and our experience is that very low LODs are achievable, but a user "right at the feet of the spectrometer" is mandatory..hope i've explained myself enough.
Dear Salvador: I agree with you. I think that they require an experience user supervising all.
Regards, Raúl
In my work I use old equipment currently at the edge of work life . I managed to reach 0.8ppb LOQ for Se , 1 and 6 ppb LOQ for As and Hg respectively. Without complex optimization of equipment, just with single test run. So sub ppb levels are completely possible with modern equipment.
Vladimir Ciovarnache -ICPT (OMV Petrom )
we work in the past with AAS hydride for Hg, As,. With the new ICP OES we do not have hydride system - because As is seldom required from our samples and for Hg we have an Lumex- 915 - has an incredible sensitivity and selectivity , but is only for Hg
Dear Salvador
if you need more sensivity you can used an ultrasonic nebulizer.
We have acquired recently an MP-AES but we are not satisfied by this technique
Best Regards
Dear Baghdag, we've been considering MP-AES as an option, but the sensibility required in tap water regulations is not satisfied with this technology. What did you expected that the equipment didn't fulfill?
Dear Abu, are you using an MSIS nebulization chamber or an standard hydride generator?
Hi
Dear all,
I work on ICP-OES 2100DV Perkin Elmer
Results for As,Sb, and Se
Best regards
Rafael Isayev
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