devising a water sample test

[passivepsycho]

Hi,

 

I would like to conduct a little research on my own to help bolster my resume when it comes time for me to graduate in a few years. I recently changed my major to chemical engineering and immediately received a scholarship so I kinda feel obligated to move forward fast. Anyways, I've been racking my brain trying to think of something that's easy enough for me to do, yet hard enough for them to let me do it and I came up with testing municipal water supplies for the presence of antidepressants and the possible affects on the average city dweller. My question is this, is there any quick test I can use to detect the presence of pharmaceuticals in tap water. What I'm looking for is a field test and if it registers positive I can use gas chromatography (with advisers permission) or some other test to find actual ppm/ppb but lab time is at a premium so a field test would be wonderful. I've lined up people in several metropolitan areas around the country who will provide me with water samples just need a jumping off point. Any advice for me?

 

Thanks,

 

PP

[John Cuthber]

"My question is this, is there any quick test I can use to detect the presence of pharmaceuticals in tap water."

Probably not, or at least not at the sort of levels I would expect.

Sertraline is probably as good an example as any. There were, according to WIKI about 30 million prescriptions for it in the US in 2007. Typical doses are 100 mg a day so that's about about 3 tons a day. Per capita water use in the states is about given as about 70 gallons a day. About 265 litres a day. There are about 300 million people in the US so that's about 78 million tons of water a day for domestic use. So, on average you are down to about 40 parts per billion.

Then you need to add industrial use of water and storm drainage.

Then there's the fact that some (perhaps most) of it will be destroyed metabolically, rather than excreted as such.

My guess is that you are talking about parts per trillion in many cases, and that's for the most heavily prescribed antidepressant.

 

There's some data here

http://www.speclab.com/compound/c58082.htm

about caffeine in river water- the levels are low ppb. A lot more people use caffeine than antidepressants.

 

Then there's the fact that municipal water supplies are cleaned up before use.

 

I doubt that I (as a professional chemist with experience in pharmaceutical measurements and access to a well stocked lab) could measure the amounts of antidepressants in most drinking water unless something had gone catastrophically wrong.

 

Sorry.