Absorbance of Bisphenol A by Plastics
Anna Foote, Dr. Alfred Conklin, Jr.
Chemistry Department
Wilmington College
RESULTS
Abstract
The BPA standard showed the absorbance of 2.8530 at the expected wavelength
276nm. When the BPA standard was filtered through cotton the average absorbance
was 1.9157 at 276nm indicating BPA was absorbed by the cotton. The absorbance of
BPA through the PETE plastic was 1.9509 at 274nm. The absorbance of BPA
through the HDPE plastic was 1.8174 at 277nm. The absorbance of BPA through the
PP plastic was 1.8165 at 277nm.
Previous work has shown Bisphenol A (BPA) is absorbed by filter and
extraction media. In this work we investigated the sorbance of BPA by
used plastics (the structure of BPA is shown in Figure 1). We hypothesize
that used plastics can be ground and used to remove BPA from aqueous
solution. A standard BPA solution was passed through different kinds of
ground plastic and their sorbance of BPA was measured using Ultra-Violet
visible spectroscopy.
Introduction
BPA is used in plastics such as polycarbonates and for epoxy resins used to
line metal food cans and baby formula containers. It has been found to be a
hormone disruptor and poses a risk to human development. BPA became a
household name within the last decade when it was proven that the
chemical could leach from plastics that were heated and could leach from
epoxy resins used to cover the inside of baby formula containers. Over a
dozen states including California, Delaware, Minnesota, Connecticut, New
York, Washington, Wisconsin, and New Jersey have banned the use of BPA
in baby bottles and products for children. According to the U.S.
Environmental Protection Agency over one million pounds of BPA is
released into the environment each year. Due to BPA’s carcinogenic
properties removal of BPA from the environment has become of great
interest.
Sample
BPA Standard
Wavelength (nm)
276.6
Absorbance
2.853
Cotton
PETE
HDPE
PP
276
273.4
277.6
277
1.9157
1.9509
1.8174
1.8165
Table 1. Absorbance of a BPA standard solution through cotton
and different plastics.
CONCLUSIONS
Figure 2. The UV-vis spectrum in red shows the absorbance of
the BPA standard. The UV-vis spectrum in black shows the
absorbance of the BPA solution after cotton filtration.
The UV-vis spectrum of BPA shows strong absorbance at 277nm as shown in Figure
2. The UV-vis spectrum of the 200ppm standard BPA used in this experiment showed
a strong absorbance at 276nm confirming the standard solution did contain BPA
(Table 1). The difference in absorbance around the wavelength 276nm for the BPA
standard and the filtrered BPA standard through cotton showed that the cotton filter
had absorbed some BPA from the aqueous solution (Table 1). The filtration of BPA
standard through PETE plastic and cotton did not appear to absorb BPA from the
aqueous solution. The filtration of the BPA standard through HDPE plastic and PP
plastic did show that the plastic adsorbed some BPA from the aqueous solution.
Larger numbers of test samples need to be run in order to confirm that these plastics
are removing significant amounts of BPA from aqueous solution.
Figure 1. Structure of Bisphenol A
Experimental
Figure 4. Symbols, found on the bottoms of plastic containers, showing the composition of plastic.
Acknowledgements
A 200ppm BPA standard solution was prepared by adding 0.0204g of fine
ground BPA powder to 100mL of distilled water. A UV-vis spectrum of the
BPA standard was obtained. 1mL of BPA standard was then filtered through
cotton and UV-vis spectra of each sample was obtained. Absorbance at
wavelength 276nm was noted for each UV-vis spectra. A1mL sample of
BPA standard was then added to about 0.200g of a ground plastic and
filtered though cotton as shown in Figure 3. The plastics used for each
sample were polyethylene terephthalate (PETE), high density polyethylene
(HDPE), and polypropylene (PP). Standard symboles for these plastics are
shown in Figure 4. UV-vis spectra of the filtered BPA solution was then
obtained for each plastic and the absorbance at 277 nm measured.
I’d like to thank my research advisor Dr. Al Conklin and the Wilmington College
Chemistry Department for supplying materials and guidance on my research. This
work was supported by the Wilmington College Chemistry Department.
References
Figure 3. Experimental set-up of cotton filtration.
1. Bisphenol A Released From Polycarbonate Drinking Bottles and Mimics
Neutotoxic Actions of Estrogen Developing Cerebellar Neurans. Science Direct
9 Nov 2007: 149-156
2. Biro, Frank (2011) Research Horizons: All Around Us. Cincinnati Children’s
Research Foundation. Pg 20-23
3. Hogue, Cheryl. States Continue to Ban Chemicals. Chemical and
Engineering News. Published by The American Chemical Society Oct 3, 2011.
Pg 32
4. Weng,Yu-I et al (2011) Epigenetic influences of low-dose biphenyl A in
primary human breast epithelial cells. Toxicology and Applied Pharmacology
248:111-121
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