According to a paper recently published in the journal of chromatography A, a research team led by Prof. SHENG Chengyin and Associate Prof. ZOU Xue from Hefei Institutes of Physical Science (HFIPS) of the Chinese Academy of Sciences (CAS) successfully determined butanol in latex paint via fast gas chromatography proton transfer reaction mass spectrometry (FastGC-PTR-MS) technology.
Proton transfer reaction mass spectrometry (PTR-MS) and the gas chromatography mass spectrometer (GC-MS) are two common VOC detection technologies. The PTR-MS technology is quick and sensitive but it can only identify the VOCs based on mass charge ratio (m/z), which means it is impossible to distinguish VOCs with the same molecular weight, such as isomers. And GC-MS is time-consuming because of the chromatographic separation process and complex sample pretreatment.
To solve these problems, the research team built a tandem technology FastGC-PTR-MS, combining the advantages of rapid detection of PTR-MS with the separation and qualitative capabilities of GC-MS.
Scientists optimized the developed technology with standard samples of several common VOCs.
They successfully separated the isomers. The retention times of acetonitrile, acetone, alcohols and benzene series were all less than 2 min， which was 2-6 times shorter than that of commercial GC-MS.
Then they applied the FastGC-PTR-MS to detect the isomers of butanol in latex paint, and found that the headspace of brand D latex paint mainly contained tert-butanol (4.41 ppmv), n-butanol, acetaldehyde, methanol, and acetone. The concentration of tert-butanol was much less than the maximum allowable concentration in the workplace (100 ppmv).
"The FastGC-PTR-MS could be used for rapid qualitative and quantitative detection of isomers," said SUN Qin, first author of the paper.
This work was supported by the National Natural Science Foundation of China, the Youth Innovation Promotion Association of CAS, the Anhui Provincial Key R&D Program, and the HFIPS Director's Fund.
Schematic diagram of the FastGC-PTR-MS. (Image by Sun Qin)