TY - JOUR
T1 - Determination of homologues of quaternary ammonium surfactants by capillary electrophoresis using indirect UV detection
AU - Liu, Hsueh Ying
AU - Ding, Wang Hsien
N1 - Funding Information:
The authors would like to thank the National Science Council of Taiwan for financially supporting this research under contract no. NSC 91-2113-M-008-020.
PY - 2004/2/6
Y1 - 2004/2/6
N2 - This investigation describes the simultaneous separation of two major non-chromophoric quaternary ammonium surfactants, alkyltrimethyl- and dialkyldimethylammonium compounds (ATMACs and DADMACs, respectively), by capillary electrophoresis (CE) using indirect UV detection. The most effective separation conditions was 10mM phosphate buffer with 57.5% tetrahydrofuran and 3mM sodium dodecyl sulfate (SDS) at pH 4.3, and the sample hydrodynamic injection of up to 20s at 1psi (approximately 60nl), and an applied voltage of 25kV (1psi=6.9kPa). Specially, the selection of an appropriate chromophore and an internal standard (I.S.) to improve the peak identification and quantitation was systematically investigated. Decylbenzyldimethyl ammonium chloride (C 10-BDMA+C-) as a chromophore with 3mM sodium dodecyl sulfate provided the best detectability for all homologues. The reproducibility of the migration time and quantitative analysis can be improved by using tetraoctyl ammonium ion as an internal standard, giving the relative standard deviation (R.S.D.) less than 0.8% for the relative migration times, and 2.5-5.5% for the relative peak areas. A good linearity of CE analysis was obtained in the range of 1.0-20μg/ml with r2 values of above 0.999. The analysis of cationic surfactants in commercial products of hair conditioners and fabric softeners was also performed. Electrospray mass spectrometric method was applied to evaluate the CE method, and the compatible results were obtained.
AB - This investigation describes the simultaneous separation of two major non-chromophoric quaternary ammonium surfactants, alkyltrimethyl- and dialkyldimethylammonium compounds (ATMACs and DADMACs, respectively), by capillary electrophoresis (CE) using indirect UV detection. The most effective separation conditions was 10mM phosphate buffer with 57.5% tetrahydrofuran and 3mM sodium dodecyl sulfate (SDS) at pH 4.3, and the sample hydrodynamic injection of up to 20s at 1psi (approximately 60nl), and an applied voltage of 25kV (1psi=6.9kPa). Specially, the selection of an appropriate chromophore and an internal standard (I.S.) to improve the peak identification and quantitation was systematically investigated. Decylbenzyldimethyl ammonium chloride (C 10-BDMA+C-) as a chromophore with 3mM sodium dodecyl sulfate provided the best detectability for all homologues. The reproducibility of the migration time and quantitative analysis can be improved by using tetraoctyl ammonium ion as an internal standard, giving the relative standard deviation (R.S.D.) less than 0.8% for the relative migration times, and 2.5-5.5% for the relative peak areas. A good linearity of CE analysis was obtained in the range of 1.0-20μg/ml with r2 values of above 0.999. The analysis of cationic surfactants in commercial products of hair conditioners and fabric softeners was also performed. Electrospray mass spectrometric method was applied to evaluate the CE method, and the compatible results were obtained.
KW - Quaternary ammonium compounds
KW - Surfactants
UR - http://www.scopus.com/inward/record.url?scp=0347063918&partnerID=8YFLogxK
U2 - 10.1016/j.chroma.2003.10.108
DO - 10.1016/j.chroma.2003.10.108
M3 - 期刊論文
C2 - 14763815
AN - SCOPUS:0347063918
SN - 0021-9673
VL - 1025
SP - 303
EP - 312
JO - Journal of Chromatography A
JF - Journal of Chromatography A
IS - 2
ER -