Table 2.

Study of matrix effect in the surveyed samples spiked at different concentrations.

Analyte	Mean relative recovery ± standard deviation (n = 3)
	Mouthwash 1 (%)	Mouthwash 2 (%)	Mouthwash 3 (%)	Hydrating gel 1 (%)	Hydrating gel 2 (%)	Hydrating gel 3 (%)
All samples were spiked with each paraben at a concentration of 1 mg L-1
Mep	115 ± 3	106 ± 2	111 ± 3	94 ± 4	96 ± 2	84 ± 2
Etp	85 ± 3	91 ± 1	84 ± 2	88 ± 3	87 ± 2	85 ± 3
Prp	88 ± 2	94 ± 3	89 ± 2	100 ± 3	93 ± 4	87 ± 3
All samples were spiked with each paraben at a concentration of 5 mg L-1
Mep	109 ± 2	105 ± 3	116 ± 2	96 ± 3	93 ± 4	88 ± 2
Etp	87 ± 2	93 ± 2	87 ± 3	90 ± 3	90 ± 3	89 ± 2
Prp	86 ± 3	90 ± 1	91 ± 2	98 ± 2	87 ± 2	91 ± 3
All samples were spiked with each paraben at a concentration of 10 mg L-1
Mep	105 ± 3	103 ± 3	109 ± 3	101 ± 2	95 ± 3	93 ± 4
Etp	90 ± 4	96 ± 3	94 ± 3	97 ± 3	89 ± 2	95 ± 2
Prp	84 ± 3	97 ± 2	96 ± 4	103 ± 2	95 ± 4	94 ± 3