IMSC 2012: Simultaneous analysis of anionic, amphoteric and non-ionic surfactants using ultra-high speed LC-MS/MS

Significance of the Topic

Surfactants are key ingredients in household and industrial products including detergents personal care and cleaning agents They also pose environmental concerns due to their persistence and toxicity requiring sensitive analytical methods for monitoring

Study Objectives and Overview

This study aimed to develop a rapid ultra high speed LC MS MS method capable of simultaneously analyzing representative anionic amphoteric and non ionic surfactants in a single run The target compounds included linear alkylbenzene sulfonates Betaines and heptaethyleneglycol dodecyl ether

Methodology and Instrumentation

Standard mixtures were prepared by diluting commercial surfactant solutions with water acetonitrile The separation was performed on a C8 column with a binary gradient of ammonium acetate buffer acetonitrile and isopropanol under ultra high performance conditions Electrospray ionization in positive and negative modes was used with multiple reaction monitoring transitions optimized by flow injection analysis

Used Instrumentation

Shimadzu Nexera MP UHPLC system coupled to a Shimadzu LCMS 8040 triple quadrupole mass spectrometer YMC Triart C8 column 100 mm × 2.0 mm id 1.9 µm ESI source with high speed polarity switching (15 ms) Ultra fast MRM capable of over 500 transitions per second

Main Results and Discussion

Nine surfactants (LAS C10 C11 C12 C13 C14 Betaines C10 C12 C14 and HEDE) were baseline separated in under 2.5 minutes within a 5 minute cycle including column washing Calibration curves were linear in the ppb range with correlation coefficients above 0.997 Sample analysis of diluted liquid soap revealed 5 to 6 ppb of LAS C12 and C13 corresponding to 5 to 6 ppm in the undiluted product Kitchen detergent contained approximately 40 ppm of LAS homologues and 30 to 45 ppm of amphoteric and non ionic surfactants

Benefits and Practical Applications

The method enables fast high throughput screening of multi class surfactants with minimal sample preparation Its sensitivity at the ppb level supports quality control in product development and environmental monitoring of water soil and consumer goods extracts

Future Trends and Applications

Future work may extend this approach to a broader range of surfactant chemistries and complex matrices including sediments and food samples Automation of sample processing and adoption of greener solvents could enhance laboratory efficiency Continued improvements in polarity switching speed and detector performance will further increase throughput

Conclusion

An ultra high speed LC MS MS method was successfully established for simultaneous analysis of anionic amphoteric and non ionic surfactants Achieving rapid separation high sensitivity and robust quantification this protocol is well suited for routine analysis in industrial and environmental laboratories

References

No external references were cited in the source document.