Determination of benzoic acid and sorbic acid in food products using electrokinetic flow analysis-ion pair solid phase extraction-capillary zone electrophoresis.
An electrokinetic flow analysis system (EFA), consisting of one electroosmotic pump, five solenoid valves and one on-line homemade solid phase extraction (SPE) unit, combined with capillary zone electrophoresis (CZE) was proposed to determine benzoic acid and sorbic acid in food products. Tetrabutylammonium bromide (TBAB) was adopted as an ion pair reagent to improve the retention of the preservatives on C(8)-bonded silica sorbent, which was also used to remove sample matrices. By using the SPE unit, the EFA-SPE-CZE system was able to perform the SPE operation and CZE separation simultaneously. With a modified interface of EFA and CZE, the buffer consumption was reduced to 130 microL for each running. The preservatives were separated and determined under optimized conditions with p-hydroxybenzoic acid as an internal standard. The relative standard deviation (R.S.D.) of peak area for each analyte was less than 3.1% (n=5) and the limits of detection (LODs) ranged from 10 to 20 ngmL(-1) (K=3, n=11).
Han
Fang
F
Department of Chemistry, University of Science and Technology of China, Hefei, Anhui 230026, PR China.
He
You-Zhao
YZ
Li
Lian
L
Fu
Guo-Ni
GN
Xie
Hai-Yang
HY
Gan
Wu-Er
WE
D000818:Animals; D019817:Benzoic Acid / Q000032:analysis*; D001628:Beverages; D004563:Electrochemistry; D019075:Electrophoresis, Capillary / Q000295:instrumentation / Q000379:methods; D017022:Flow Injection Analysis / Q000295:instrumentation / Q000379:methods; D005504:Food Analysis / Q000295:instrumentation / Q000379:methods; D005638:Fruit / Q000737:chemistry*; D007700:Kinetics; D008892:Milk / Q000737:chemistry*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D052616:Solid Phase Extraction / Q000295:instrumentation / Q000379:methods*; D013011:Sorbic Acid / Q000032:analysis*; D013025:Glycine max / Q000737:chemistry*; D013997:Time Factors
D019817:Benzoic Acid; D013011:Sorbic Acid