Detection and identification of chemical derivatives formed from pyrotechnic smoke reactions
Provided is a method to initiate and analyze chemical derivatives formed from pyrotechnic smoke reactions. Milligram quantities of a lab-scale pyrotechnic smoke composition are reacted by encapsulation with a metal probe that is rapidly heated, which then sublimes the organic dye, allowing for the testing of all of the gas-phase products for identification by pyrolysis-gas chromatography-mass spectrometry. The thermally decomposed ingredients and new side product derivatives are identified at lower relative abundances compared to the intact organic dye. Any remaining residues within the thermal probe are optionally reconstituted into solution for further analysis by liquid chromatography-mass spectrometry if desired. The results are processed via a machine learning quantitative structure-activity relationship model that provides data related to health and environmental hazards.
1 . A method for analyzing one or more chemical products formed from pyrotechnic smoke reactions comprising:
encapsulating a quantity of a pyrotechnic smoke composition;
pyrolyizing said quantity with a heat source to produce said one or more chemical products;
performing pyrolysis-gas chromatography-mass spectrometry of said one or more chemical products and identifying a primary peak from said one or more chemical products;
identifying a primary dye molecule from said primary peak;
performing a rat inhalation LC 50 analysis by determining a concentration in mg·L −1 of said primary dye molecule that kills half of rats by inhalation in 4 hours.
2 . The method of claim 1 , wherein said encapsulated pyrotechnic smoke composition is initiated via a metal probe that is rapidly heated.
3 . The method of claim 1 , wherein pyrolyizing produces a redox reaction that sublimes one or more organic dyes in said composition.
4 . The method of claim 3 , wherein said one or more chemical products identified by pyrolysis-gas chromatography-mass spectrometry are gas-phase products.
5 . The method of claim 4 , wherein said one or more chemical products comprise thermally decomposed ingredients and side product derivatives are identified at lower relative abundances compared to the said one or more organic dyes.
6 . The method of claim 1 , wherein, remaining residues within said thermal probe are reconstituted for further analysis by liquid chromatography-mass spectrometry.
7 . The method of claim 1 , wherein said rat inhalation LC 50 analysis further comprises,
the step of assigning a score of very high if LC 50 ≤2, a score of high if 2<LC 50 ≤10, a score of medium if 10<LC 50 ≤20, and a score of low if LC 50 >20.