Under optimized experimental conditions, the relative standard deviation (RSD) was obtained by measuring the characteristic
fragment abundances (MS/MS) of typical illicit compounds spiked
in the cream samples for multiple times. For example, the RSD (n= 6) for oxybenzone (20 ppb), 4-aminobenzoic acid (10 ppb) and
avobenzone (20 ppb) were 12.2%, 8.4% and 16.0%, respectively.
Above mentioned values were acquired during ten measurements
of adulterated cream samples containing the analytes at the concentration equal to 50 times of the LOD. The RSD data showed the
method provided a reasonable deviation for trace detection of the
analytes.