Testing for Chloroquine Phosphate

LFS · Jun 4, 2016

I know some here have tested for Choloroquine Phosphate with Spectrophotometer's. I am in touch with Hach on purchasing a device to test for trace elements, but I would also like to be able to test for Chloroquine Phosphate levels.

If you are testing for CP levels, please let me know what device you are using what it is you are actually testing for (so Hach can help me out some more) since they don't have a specific test for CP. They gave me some options of what I could test for and what machines would do those tests, but they were unclear of which would work and what the aquarium industry standard is.

Humblefish · Jun 4, 2016

@Reef Fever (below) says they use a Hach DR5000 to test for CP at the public aquarium where he works. Perhaps he'll chime in with a recommendation on a newer model. @omykiss001 or @Randy Holmes-Farley might possibly have a recommendation as well.

Reef Fever said:
Testing it on a Hach DR5000, a recently discontinued, but once very expensive spectrophotometer. I work at a public aquarium, we use it for daily water quality monitoring

omykiss001 · Jun 5, 2016

I'm guessing any UV vis spec will do the job. Not certain how they test for CP using one so that would be helpful in recommending any particular model. But Hach is a good brand and as long as a full spectrum you will probably be fine.

LFS · Jun 17, 2016

Still looking for a proper test. I have not had any luck with any of the equipment manufactures or vendors who sell CP...

Reefahholic · Jun 17, 2016

A Hach for copper testing is the best out there to my knowledge. They're pricey though. That's why I use another kit that's very accurate but also affordable.

I wonder how much the Hach for CP would run you?

LFS · Jun 17, 2016

I am looking to purchase a Hach or Hanna colorimeter. Cost is not the object, it is getting someone to help me find out how the test is performed.

If I need a different piece of equipment then I will.

omykiss001 · Jul 1, 2016

I can't remember the thread it may be this or where someone posted a C of A for CP sourced out of China if I remember correctly they were simply verifying purity of the CP by a simple absorbance measure. Here's the rub unless someone already has the data you'd need to generate a standard curve of CP concentration vs. absorbance at I think it was 280 or 260 nm. Using the standard curve you could then determine an unknown simply by using the absorbance measure of CP in the solution you'd like to test. I don't know how salt mix would affect the reading, but my guess would be as long as you blank the instrument using the a similar batch of salt that the CP is dissolved in the error would be minimal. To generate the standard curve you'd need CP at a known purity, an analytical balance, and (if really anal-retentive) volumetric flasks to generate solutions of known, accurate concentrations to build the regression curve.

There was a guy on the threads who works for a public aquarium that uses CP and I think they use an absorbance assay to determine CP levels in the water. Perhaps he has a standard curve or the regression equation that can be used to determine CP levels if you had the spectraphotometer. As UV absorbance is UV absorbance and would be instrument independent for the most part. If someone had the equipment one could also gauge how pure the stuff coming out of china was and could correct for purity issues and be able to use that stuff just as effectively as the pharmaceutical grade stuff. @Humblefish you might remember what thread the guy who works at the aquarium that uses CP and ping out to him to see what they do.

Hopefully this all makes sense.