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- Posts: 10
- Joined: Fri Oct 28, 2022 6:47 am
- Location: Ελλάδα
I have posted again about this topic. I am having lots of trouble with method, since ballast waters are seawaters and method EPA 300.1 is about drinking waters mostly.
Anyway, first off, I would like to know what is the best way to spike. Let me explain: so my two analytes are chlorite anion and chlorate anion. My lowest standard is 4ppb and I am trying to spike my lowest sample at my ballast waters samples. (I am doing this in order to prove that I can indeed determine at such levels my analytes in a sample such as seawater). So what I do is I have a High Concentration Standard at 10ppm. I take 40uL of this and add it to a 100mL volumetric flask. I add 1mL of my sample and dilute to volume with HPLC grade water. When I do this I see no peaks. Is it something wrong with the way I spike or are there any interferences I need to evaluate?
Second of all the chromatogram in this analysis is not a perfect one. It has lots of broads peaks and my analytes are always next and almost on top of other nearby peaks. I do not use the column that is suggested (i use a metrosepp A supp 5 instead of a metrosepp A supp 7), because in drinking waters and in my standards the column I use seems to do fine, with great linearity and sharp peaks. It's on the samples of seawaters that I have the problem. Do you think that changing the column would help?
Thanks in advance!!