Analysis of Ultraviolet Absorbers in Sunscreen Cream by HPLC

About the Author

Satoko Suzuki is a senior manager of the molecular spectroscopy applications laboratory at the JASCO facility in Hachioji Japan.

Introduction

In 2008, Italian scientists published their results showing that oxybenzone, benzophenone and cinnamic acid, the major components of UV absorbers, are responsible for coral bleaching (i.e., death). In 2015, results showing that the chemicals affect coral DNA even at low concentrations were published in a scientific journal of Environmental Toxicology. An ordinance that bans the sale and distribution of sunscreens containing oxybenzone (HMB) and octinoxate (EMC) was enacted in 2018 and came into effect on January 1, 2021 in Hawaii. These ordinances and bills are set to come into effect at the same time in Key West, Florida and Bonaire, the Caribbean; thus, regulations have started to be taken around the world. In Japan, however, products using these components are still sold because of the absence of such regulations, and their use is not banned either. Nevertheless, we encourage to choose UV-absorber-free or environmentally friendly products when visiting such regulated areas.

Here, we report the results of our simultaneous analysis measuring 11 components of UV absorbers contained in a commercially available sunscreen cream.

Experimental

Instruments
Pump	PU-4180-LPG
Autosampler	AS-4150
Column oven	CO-4060
PDA detector	MD-4010

HPLC Conditions
Column	CrestPak C8T-5 (4.6 mm I.D. x 250 mm L, 5 µm)
Eluent A	1.5 % formic acid
Eluent B	Acetonitrile
Gradient	A/B = 60/40 (0.00 min.) --> 0/80 (4.00 min.) --> 10/90 (12.00 min.) --> 5/95 (12.05 min.) --> 5/95 (14.00 min.) --> 60/40 (14.05 min.), 1cycle; 22 min.
Flow Rate	1.0 mL/min.
Column Temperature	40 ºC
Wavelength	200 - 500 nm
Injection Volume	5 µL
Standard	11 ultraviolet absorbers mixture in acetonitrile (Refer to the data for concentrations.)
Sample	Sunscreen cream (Pretreatment method is described later.)

Figure 2 shows a procedure for the extraction from a sunscreen cream. Figure 3 shows chromatograms for the extract from sunscreen cream. Figure 4 shows the result of a spectral search for the peaks from the extract of sunscreen cream. The spectrum obtained for the eluted peak from cream extract was compared with spectra in a spectral library, to which the spectra for 11 standard samples had been registered in advance. It revealed a high correlation coefficient of 0.999 with the spectrum of EMC.

Keywords

920014X, HPLC, PDA detector, ultraviolet absorbers, sunscreen cream, C8, EXTREMA

Results

Figure 1-1 shows a chromatogram and a contour map for a mixture of 11 standard ultraviolet absorbers obtained using a PDA detector. Figure 1-2 shows spectra acquired at the top of different peaks.

**Fig. 1-1** Chromatogram and contour map of ultraviolet absorbers standard mixture obtained by a PDA detector (50 µg/mL each). (A) : UV chromatogram (280, 310 nm), (B) : contour map. 1: HMC, 2: HMBS, 3: THB, 4: EAB, 5: DHB, 6: DHDMB, 7: HMB, 8: BMB, 9: EMC, 10: ECA, 11: EHS

**Fig. 1-2** On-peak spectra of eleven ultraviolet absorbers.
1: HMC, 2: HMBS, 3: THB, 4: EAB, 5: DHB, 6: DHDMB, 7: HMB, 8: BMB, 9: EMC, 10: ECA, 11: EHS.

**Fig. 2** Procedure for extraction from sunscreen cream

**Fig. 3** Chromatogram of sunscreen cream
(A) Standard, (B) Extract.
1: HMC, 2: HMBS, 3: THB, 4: EAB, 5: DHB, 6: DHDMB, 7: HMB, 8: BMB, 9: EMC, 10: ECA, 11: EHS.

**Fig. 4** Spectral search result for sunscreen cream extract.
(A): Spectrum of Peak 9, (B): Spectrum of EMC.

This document has been prepared based on information available at the time of publication and is subject to revision without notice. Although the contents are checked with the utmost care, we do not guarantee their accuracy or completeness. JASCO Corporation assumes no responsibility or liability for any loss or damage incurred as a result of the use of any information contained in this document. Copyright and other intellectual property rights in this document remain the property of JASCO Corporation. Please do not attempt to copy, modify, redistribute, or sell etc. in whole or in part without prior written permission.

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