Patent ID: 9715998
Date: 2017-07-25
CPC Classifications: H01J

Claim:
1. A method for monitoring level of paraben in cosmetics comprising: dissolving a sample in a solvent and obtaining a supernatant containing paraben by ultrasonic vibration and high speed centrifugation; performing a derivatization reaction between a derivatization reagent and paraben by adding the derivatization reagent into the supernatant containing paraben to obtain a derivatization solution containing a tagged paraben; extracting the derivatization solution containing the tagged paraben with an extractant to obtain an extract containing the tagged paraben; co-crystallizing the extract containing the tagged paraben and α-cyanol-4-hydroxycinnamic acid (CHCA) as a matrix to form a co-crystallized extract-matrix mixture; ionizing the co-crystallized extract-matrix mixture by a laser beam having a wavelength of 330 to 360 nm to form a vaporized ion; and analyzing mass-to-charge ratio of the vaporized ion with an analyzer to determine molecular weight thereof.