Abstract
This paper describes a simple method for quantifying phthalates via the conversion of anhydrous phthalates to a dye. The phthalate was hydrolyzed with sodium hydroxide and dehydrated to form phthalic anhydride, which was converted to a marker, namely fluorescein, by reaction with resorcinol. Concentrated sulfuric acid was used as the catalyst. The presence of a phthalate was determined by absorbance spectrophotometry. The detection limit of this method for di(2-ethylhexyl) phthalate was 0.1 μmol, and the relative standard deviation with respect to reproducibility was approximately 10% (n = 3). For other phthalates, namely diisobutyl phthalate, dibutyl phthalate, bis(butylbenzyl) phthalate, di-n-octyl phthalate, diisononyl phthalate, and diisodecyl phthalate, the absorbance deviation was less than 20%, which is within the acceptable range for screening purposes. Because the phthalates were hydrolyzed to enable colorimetric determination, the identification of individual phthalates is beyond the scope of this method. However, this simple colorimetric method can easily be used to determine the total amount of phthalates in real samples at the submicromolar level, by converting the phthalates to dyes. The applicability of this method was investigated by analyzing actual samples containing various phthalates. The quantitative results were almost the same as those obtained by using a conventional gas chromatographic method.
Similar content being viewed by others
References
G. Wypych. “Handbook of Plasticizers,” 2004, ChemTec Publishing.
U. Heudorf, V. Mersch-Sundermann, and J. Angerer, Int. J. Hyg. Environ. Health, 2007, 210, 623.
W. J. Kozumbo, R. Kroll, R. J. Rubin, Environ. Health Perspect., 1982, 45, 103.
H.-Y. Shen, Talanta, 2005, 66, 734.
International Electrotechnical Commission 2017, IEC62321 Part 8.
F. Maruyama, S. Fujimaki, Y. Sakamoto, Y. Kudo, and H. Miyagawa, Anal. Sci., 2015, 31, 3.
H. Yanagisawa, Y. Kudo, K. Nakagawa, H. Miyagawa, F. Maruyama, and S. Fujimaki, Molecules, 2018, 23, 728.
H. Yanagisawa, F. Maruyama, and S. Fujimaki, J. Anal. Appl. Pyrolysis, 2019, 137, 37.
Y. R. Shashoua, Polym. Degrad. Stab., 2003, 81, 29.
C. Wang, D. Johnson, M. A. Suleman, M. A. Suleman, W. Zhang, D. Pestov, P. Ramsinghani, R. Wickham, and K. J. Wynne, Polymer, 2015, 76, 70.
M. Zhang, Y.-Q. Liu, and B.-C. Ye, Chem. Commun., 2011, 47, 11849.
G. M. Ziarani, R. Moradi, N. Lashgari, and H. G. Kruger, in “Metal-Free Synthetic Organic Dyes”, ed. G. M. Ziarani, R. Moradi, N. Lashgari, and H. G. Kruger, 2018, Elsevier, 165.
M. N. Bobrow, G. J. Litt, K. J. Shaughnessy, P. C. Mayer, and J. Conlon, J. Immunol. Methods, 1992, 150, 145.
H. Yanagisawa, A. Hirano, and M. Sugawara, Anal. Biochem., 2004, 332, 358.
W. C. W. Chan and S. Nie, Science, 1998, 281, 2016.
R. Sjöback, J. Nygren, and M. Kubista, Spectrochim. Acta, Part A, 1995, 51, L7.
B. C. Pan, Y. Xiong, A. M. Li, J. L. Chen, Q. X. Zhang, and X. Y. Jin, React. Funct. Polym., 2002, 53, 63.
T. Litovitz, Pediatr. Clin. North Am., 1986, 33, 311.
Acknowledgments
The authors are grateful to Dr. K. Nakagawa, Mr. Y. Kudo, and Mr. H. Miyagawa of the Analytical & Measuring Instrument Division, Shimadzu Corporation, and Mr. Maruyama Fumitaka of SGS Japan Inc. for their thoughtful suggestions and helpful discussions.
Author information
Authors and Affiliations
Corresponding author
Electronic supplementary material
Rights and permissions
About this article
Cite this article
Yanagisawa, H., Fujimaki, S. Simple Colorimetric Determination of Phthalates in Polymers by Dye Formation. ANAL. SCI. 35, 1215–1219 (2019). https://doi.org/10.2116/analsci.19P165
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.2116/analsci.19P165