Jaymz

My first reaction to getting no readings at all for chlorates was that the chlorate levels in the dust were very low. However i performed the following test to check on this:

1) spiked the dust sample with a 10ppm standard solution (of chlorate obviously) - this is well within my detection limits
2) evaporated the dust sample to dryness (gentle heating)
3) then i performed the usual 'extraction' with 5mL of deionized water and vigorous shaking
4) then i perform my usual test for chlorates and somehow all the chlorates have vanished hehe

So the problem seems to be in the extraction method, which is quite crude in my opinion and should definitely be improved. The question is how? Because the best solvent for chlorates seems to be water, and with acid too many species will dissolve. However simply adding water seems to be inadequate

Btw. I'm working on aerial dustfall, so i'm collecting dust from the rooftops of buildings over a 30 day period using an appropriate sampling device. So it's not purely an aerosol study as precipiataion (just rain, no snow or ice or anything) was quite frequent during my sampling period

Thx glad to be part of it. I did consider that the chlorates are actually being modified in some way. Chlorates are strong oxidizers so it is highly possible that they're interacting with some form of chemical species in the dust. I did do quite a bit of background reading, however i couldn't find anything directly linked to chlorates in dust! Chlorates are sensitive to the presence of some metals as far as i know, however heating to 100^oC shouldn't induce a reaction. Thx for the link, i will read it once i get hold of the full article. I'm currently sick, so i haven't been able to perfrom further tests. I was thinking of trying some form of acid extraction. However i'm worrying that this will extract other chemical species which aren't soluble in water, which will make matters worse.

The funny thing is that my collegue is using a very similar method for perchlorates and it's working fine.

Once again any ideas to what the problem might be would be greatly appreciated as i'm kind of lost