Generally it depends on the nature of your dye - the analysis should be choosen in such way that quinoline and the dye signals will not overlap.

I think you could do MS analysis out of your sample - if there will be no signals from quinoline it will mean that the dye is quinoline-free.

Dear Ana,

according to your profil:

Environmental Science M.S.

Environmental Health and Safety Manager

Fibro Chem, LLC · Environmental Health and Safety

- I am perplexed that Fibro Chem has no chemist in RD or bulk synthesis for the solving of this trivial problem.

- If you have quinoline as impurity in your dye, Fibrom Chem sells VERY DIRTY DYES!!!!!!!!!.

- It seems that you are not familiar with web search and how to post a good question.

please answer the following questions:

-what a kind of dye (if confidential  please answer via RG message). It is important because you can wash the dye with water or CCl4 (dye must be not soluble in water or CCl4).

Other part , you can dry your dye in vacuum  with a temperature gradient . Quinoline  has a Bp. of 237, 2 °C  at   normal pressure. (see wikipedia too).

- http://www.ijppsjournal.com/Vol3Issue3/2193.pdf

To analyze a dye sample for Quinoline, what kind of test or analysis would you do?

My Answer:

-Thin Layer Chromatography   (TLC)

- GC/MS (according to the dye)

- NMR H1 and C13 (for proton NMR, you must a pure quinoline standard )

In order to see the peaks of quinoline in your dye, you'll  measure the NMR of your dye then you give few microliter of quinoline in your measured sample and take another spectrum. Then you can see the increase of quinoline peaks.

- UV-Vis according to the structure of the dye.

- Elemental analysis before and after purification.

For all these analysis you need the help of the R&D lab of your Cy.

JRG

You can add HPLC, CE and other chromatographic, spectro-analytical techniques also, based on your specifications of the mixtures and analysis requirements.

Łukasz Banach we are a small chemical and dye company with limited equipment, but most of what we have suits our needs. We have gc, but not a vacuum dryer or mass spec. Unfortunately, I do not know the details of the dye or what kind it is, as I'm hearing this information 3rd hand. From time to time, we send samples to more equipped labs for various needs.

Jean Rene Grezes, see above, I do not know what kind of dye the customer is seeking, only that they desire it to be quinoline-free. Quinoline has been an added ingredient to dyes for a long time, around the 1800s, so it is likely not an impurity. Approximately 4 tonnes are produced annually, so there is a low likelihood that commercial dyes are contaminated with large quantities of quinoline. Aged samples, if exposed to light, become yellow and later brown. Therefore I think the main reason the customer wants quinoline-free dyes is due to color change concerns. Thank you for your response.