An invention is described in Cooks, R.; Jjunju, F.; Li, A.; Roqan, I.; (Purdue Research Foundation) US Patent 10,197,547, 05-Feb-2019, that is stated to “relate to methods of analyzing crude oil.” For the PTC community, it’s much more than that. This patent addresses a long standing issue in industrial PTC research which is how to quantify the presence of quaternary ammonium salts in an organic phase, including in non-polar solvents, especially at very low concentration.
Paper-spray mass spectrometry was used to identify a variety of quat salts including tetraoctylammonium bromide, tetradodecylammonium bromide, tetrahexylammonium bromide, tetrabutylammonium hexafluorophosphate, hexadecyltrimethylammonium bromide, benzylhexadecyldimethylammonium chloride, hexadecyltrimethylammonium bromide, and a mixture of alkyldimethylbenzyl ammonium chloride where the alkyl group is predominantly n-dodecyl. In some cases, the analytical method is performed without any sample pre-purification steps.
Figure 2 in this patent shows a 5-point calibration curve for the quantitative analysis of ammonium salts in oil matrix using a commercial ion trap mass spectrometer. The R-squared value of the line was 0.997 and the highest concentration of quat was 500 parts per billion.
This patent may be of great interest to those who need to detect quat salts at low concentrations such as residual quat in product.
About Marc Halpern
Dr. Halpern is founder and president of PTC Organics, Inc., the only company dedicated exclusively to developing low-cost high-performance green chemistry processes for the manufacture of organic chemicals using Phase Transfer Catalysis. Dr. Halpern has innovated PTC breakthroughs for pharmaceuticals, agrochemicals, petrochemicals, monomers, polymers, flavors & fragrances, dyes & pigments and solvents. Dr. Halpern has provided PTC services on-site at more than 260 industrial process R&D departments in 37 countries and has helped chemical companies save > $200 million. Dr. Halpern co-authored five books including the best-selling “Phase-Transfer Catalysis: Fundamentals, Applications and Industrial Perspectives” and has presented the 2-day course “Practical Phase-Transfer Catalysis” at 50 locations in the US, Europe and Asia.
Dr. Halpern founded the journal “Industrial Phase-Transfer Catalysis” and “The PTC Tip of the Month” enjoyed by 2,100 qualified subscribers, now beyond 130 issues. In 2014, Dr. Halpern is celebrating his 30th year in the chemical industry, including serving as a process chemist at Dow Chemical, a supervisor of process chemistry at ICI, Director of R&D at Sybron Chemicals and founder and president of PTC Organics Inc. (15 years) and PTC Communications Inc. (20 years). Dr. Halpern also co-founded PTC Interface Inc. in 1989 and PTC Value Recovery Inc. in 1999. His academic breakthroughs include the PTC pKa Guidelines, the q-value for quat accessibility and he has achieved industrial PTC breakthroughs for a dozen strong base reactions as well as esterifications, transesterifications, epoxidations and chloromethylations plus contributed to more than 100 other industrial PTC process development projects.
Dr. Halpern has dedicated his adult life to his family and to phase-transfer catalysis (in that order!).
