Quantification of Sunscreen Benzophenone-4 in Hair Shampoos by Hydrophilic Interactions Thin-Layer Chromatography/Densitometry or Derivative UV Spectrophotometry

Table 3

Recovery studies.

% BZ4 in spiked shampoo	Chromatographic		Spectrophotometric
				0 derivative 285 nm	2nd derivative 285 nm
0.5	Theoretical; µg spot^−1	0.25^a	Shampoo sample concentration mg mL^−1	2.5	2.5
	Experimental; µg spot^−1	0.25	Experimental % BZ4 in shampoo	0.53	0.51
	Recovery %	100.0	Recovery %	106.7	102.0
	CV% ()	1.99	CV% ()	0.62	0.70
1.0	Theoretical; µg spot^−1	0.50^a	Shampoo sample concentration mg mL^−1	2.5	2.5
	Experimental; µg spot^−1	0.49	Experimental % BZ4 in shampoo	1.05	1.02
	Recovery %	98.0	Recovery %	104.7	102.0
	CV% ()	1.10	CV% ()	0.87	0.81
1.5	Theoretical; µg spot^−1	0.75^a	Shampoo sample concentration mg mL^−1	2.5	2.5
	Experimental; µg spot^−1	0.77	Experimental % BZ4 in shampoo	1.59	1.53
	Recovery %	102.7	Recovery %	106.1	102.6
	CV% ()	1.61	CV% ()	0.88	0.67
2.0	Theoretical; µg spot^−1	1.00^a	Shampoo sample concentration mg mL^−1	2.5	2.5
	Experimental; µg spot^−1	1.03	Experimental % BZ4 in shampoo	2.10	2.06
	Recovery %	103.0	Recovery %	105.1	103.2
	CV% ()	0.58	CV% ()	1.03	1.05
5.0	Theoretical; µg spot^−1	1.25^b	Shampoo sample concentration mg mL^−1	1.0	1.0
	Experimental; µg spot^−1	1.27	Experimental % BZ4 in shampoo	5.32	5.07
	Recovery %	102.0	Recovery %	106.4	101.4
	CV% ()	1.33	CV% ()	1.54	1.41

Shampoo sample concentration—50 mg mL⁻¹.
^bShampoo sample concentration—25 mg mL⁻¹.