Capillary zone electrophoresis method for the determination of inorganic anions and formic acid in honey.
A capillary zone electrophoresis method for the determination of inorganic anions and formic acid in honey samples was developed for the first time. The complete separation of chloride, nitrate, sulfate, phosphate, and formic acid was achieved with a simple electrolyte composed by 2 mM potassium dichromate as the carrier solution and background absorbance provider and 0.05 mM tetraethylenepentamine (TEPA) as electro-osmotic flow suppressor (pH 4.00). Injection was performed hydrostatically by elevating the sample at 10 cm for 10 s. The running voltage was -27 kV at 25 degrees C. Indirect UV absorption detection was achieved at 254 nm. The detection limit was in the range between 0.03 and 20 mg/kg, and the quantification limits ranged from 1.52 to 20.6 mg/kg. The calibration graphs were linear in the concentration range from the quantification limit to at least 2.5 g/kg for chloride, 0.25 g/kg for nitrate, 0.75 g/kg for sulfate, 1.50 g/kg for phosphate, and 0.75 g/kg for formic acid. Precision data in the honey samples analyzed showed repeatability and reproducibility relative standard deviations lower than 1.4 and 2.4% for migration time and lower than 1.8 and 4.3% for anion content, respectively. Recoveries of anions in honey samples analyzed ranged from 94.4 to 99.8%. Ten honey samples were analyzed to test the proposed method. Mean contents of 260.5, 3.93, 60.5, 139.4, and 209.3 mg/kg were found, respectively, for chloride, nitrate, sulfate, phosphate, and formic acid in analyzed honeys. These results agreed with literature data.
Suarez-Luque
Silvia
S
Facultad de Farmacia, Departamento de Química Analítica, Nutrición y Bromatología, Area de Nutrición y Bromatología, Universidad de Santiago, 15782 Santiago de Compostela, Galicia, Spain.
Mato
Inés
I
Huidobro
José F
JF
Simal-Lozano
Jesús
J
Sancho
M Teresa
MT
D000838:Anions / Q000032:analysis*; D002712:Chlorides / Q000032:analysis; D019075:Electrophoresis, Capillary / Q000379:methods*; D005561:Formates / Q000032:analysis*; D006722:Honey / Q000032:analysis*; D009566:Nitrates / Q000032:analysis; D010710:Phosphates / Q000032:analysis; D011786:Quality Control; D012680:Sensitivity and Specificity; D013431:Sulfates / Q000032:analysis
D000838:Anions; D002712:Chlorides; D005561:Formates; D009566:Nitrates; D010710:Phosphates; D013431:Sulfates; C030544:formic acid