Question

You are interested in thymol in mouthwash. The manufacturer lists the active ingredients as
thymol (0.064%), menthol (0.042%), eucalyptol (0.092%) and methyl salicylate. The inactive
ingredients include caramel, water and alcohol (21.6%) in addition to sodium benzoate, color,
poloxamer 407 and benzoic acid.
(a) Does thymol represent a major, minor or trace concentration?
(b) Of the ingredients listed with concentration, which ones can be considered in trace amounts?
(c) Which substance(s) is/are the sample?
(d) Which substance(s) is/are the analyte?
(e) Which substance(s) is/are the matrix?
(f) If you were to prepare a blank for your measurement, what substance(s) would it contain?

Answer 1

(a) Thymol represent as a trace concentration.

(b) Thymol, menthol and eualyptol are in trace as their concentrations are very less.

(c) Thymol containing mouthwash is the sample.

(d) Thymol is the analyte.

(e) Anything other than thymol in the mouthwash is the matrix.

(f) If we need blank we will add everything else but the thymol to get a blank so we do not get any reading from that.