Comparison of aromatic and alkyl micelles for the electrokinetic determination of phthalates in virgin olive oil.
Two electrokinetic methods for the separation of phthalates are proposed. One uses 25 mM sodium borate and 50 mM sodium taurodeoxycholate adjusted to pH 2.8, and the other uses 15 mM ammonium tetraborate, 100 mM SDS, 0.25% w:v hydroxypropylmethyl cellulose (HPMC) and 5% v:v methanol (MeoH) adjusted to pH 9. The BGE containing SDS micelles as the pseudo-stationary phase provided better analytical figures of merit, particularly as regards LOD (0.4-1.4 mg/L) and precision (1.1-6.5%). Adding MeoH and HPMC to the BGE proved essential in order to obtain narrow and symmetric peaks. The proposed method was successfully used to determine phthalates in virgin olive oil. Recoveries from spiked samples ranged from 96 to 106%. The precision obtained in the analysis of real samples, as RSD, was better than 6.8%.
Morales-Cid
Gabriel
G
Department of Analytical Chemistry, Campus de Rabanales, University of Cordoba, Cordoba, Spain.
Cárdenas
Soledad
S
Simonet
Bartolomé M
BM
Valcárcel
Miguel
M
D020374:Chromatography, Micellar Electrokinetic Capillary / Q000379:methods*; D003993:Dibutyl Phthalate / Q000032:analysis / Q000737:chemistry; D053841:Electroosmosis; D005504:Food Analysis / Q000379:methods*; D006863:Hydrogen-Ion Concentration; D000432:Methanol / Q000737:chemistry; D008823:Micelles; D008958:Models, Molecular; D000069463:Olive Oil; D010795:Phthalic Acids / Q000032:analysis* / Q000737:chemistry; D010938:Plant Oils / Q000737:chemistry*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
D008823:Micelles; D000069463:Olive Oil; D010795:Phthalic Acids; D010938:Plant Oils; C024629:dimethyl phthalate; D003993:Dibutyl Phthalate; C007379:diethyl phthalate; D000432:Methanol