Chemical Forums
Chemistry Forums for Students => Analytical Chemistry Forum => Topic started by: carnation on August 29, 2007, 01:41:57 AM
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Hi everyone,
I want to check the quality of the river by very simple methods. I decided to start with using the Test kits. But the thing is that when I run out of money, I want to prepare the test kit by myself (Some good guys can offer me the chemical). In my opinion, I will prepare the chemicals in the way that similar to the test kit that I bought, but how to prepare the Color chart exactly. I mean that we have to print out the exact color that we have when we prepare in lab by the paper. How can we do it?
P/S : the parameters that I want to check are : pH, Dissolved Oxygen, Heavy metals, Nitrite Ion, Nitrate ion, Ammonia, Chemical Oxygen Demand
Thanks for reading it
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Easier, faster and less hassle is to find a way to earn money you need. I am no joking - there are many hurdles between having a reagent and making a good, reliable test kit.
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Thank for your advice,
Anyway, in my opinion, passing the hurdle to find the way to go is interesting !!!
By this way, I produced the simple test for testing borate in sea food without alot of money. And I'm happy about this.
Earning money to buy the instruments in developing countries sometimes impossible to the people. I want to help the people in the country side by using the simple test they can check the quality of the water that they use daily (of course in doens't mean that the results are in high precision but it can provide the people some ideas about the water.
I'm on the way to find documents, yes you're right, there are so many obstacles to overcome.
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You may try this way
For example: pH standard color.
Prepare a series of buffer solution to a series of same size test tubes. Add fix volume (e.g. 3 drops) of Universal Indicator solution to each test tube and mix. Insert a rubber stopper and seal with wax or if you can seal with high temperature flame. Then this can be a series of color standard. I think paper is not a easily way to prepare because it need a quite accurate painting color.
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Thanks, I will try
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For others color standard, you may try this way :add some soluble color pigment or dye or chemicals to a series of test tubes.
For example: pink in color, you may dissolve suitable amount of potassium permanganate to water and dilute it and compare the color intensity with spectrophotometer to your standard. It is very time consuming and not very accurate but cheap.
Good luck. ;)
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thanks for your kind reply
I still have a question that in fact how can they transfer the color chart to the paper in an exact way. Do you know how they do that. What is the principle ?
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Scanning (or taking pictures) and printing with color calibration. This is more DTP then chemistry problem.
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If you look carefully to the color chart, you will see the color is little bit different to your test paper which color formation after react with the sample. It is impossible to use the same color as in the reaction because color matching (especially the color print after dried) is the professional work and very expansive.
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Yes, you're right Kevin. In Borate case, I deeped the filter paper in to the standard solution and dry it. It's OK, I can use it with the acceptable precision. But in Fe case, I can't do that.
Thanks. Best regards.
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We have bought a test kit for low level (ppb) dissolved oxygen test, the 8 colored solutions are fill in a sealed long glass tubes and form a circle which are housed in a plastic holder. The color developed sample will put at the centre of glass tubes and view under the white light to find the match color. So you may try in this way.
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Can you give methe name of the company produced your test kit. Is it the brown color or another color ?
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Please search: www.chemtech-usa.com
The color is pink.