Zhang Y.,Hebei Medical University |
Zhang Y.,Hebei Institute of Food Quality Supervision |
Ma X.F.,Hebei Institute of Food Quality Supervision |
Lv P.,Hebei Medical University |
And 3 more authors.
Analytical Letters | Year: 2014
Nitidine chloride in toothpaste was determined by two-dimensional high-performance liquid chromatography. One gradient pump was used to enrich and purify the sample. The analyte was passed into the analytical column by switching a valve following the removal of the sample matrix. The samples were extracted by ultrasonic extraction. A C18 (2.1 mm × 100 mm, 5 μm) column was used in one dimension, and a second C18 (4.6 mm × 250 mm, 5 μm) column was used in the other dimension. The mobile phase was 0.02 mol/L monobasic potassium phosphate and acetonitrile with double isocratic elution. The wavelength of the ultraviolet-visible detector was 328 nm. The linear range for nitidine chloride was between 0.01 and 2 mg/L, with a correlation coefficient greater than 0.9998. The limit of detection for nitidine chloride was 0.01 mg/kg. The mean recoveries were 88.7% to 91.0%, and the relative standard deviation was less than 2.81%. This method is simple, sensitive, and accurate for the determination of nitidine chloride in toothpaste. © 2014 Copyright Taylor & Francis Group, LLC.