Quantitative Analysis of Bisphenol A and Bisphenol F Leaching Out of Baby Feeding Bottles Using Capillary Electrophoresis

Christina DrescherSupervisor: Dr. Kingsley Donkor

Introduction Bisphenol A (BPA) and Bisphenol F (BPF) are endocrine disrupters

that can easily leach out of plastic materials baby feeding bottles

An endocrine disrupter can easily lead to harmful health effects due to its ability to mimic bodily hormones

Area of high interest in the plastic industry, especially when regardingthe safety of infants

The goal of this research is to develop a sensitive and rapid capillaryelectrophoresis (CE) method to analyze and quantify Bisphenol A andBisphenol F within baby feeding bottles from Indonesia and China.

CE experimental conditions were established to successfully separateBPA and BPF with good resolution and timely migration.

Although there has been some research conducted with regards toBisphenol A and F in baby bottles, to the best of our knowledge, this is the first analysis done using capillary electrophoresis (CE).

Method Development Four months of method development was involved for determination of

a CE separation method for BPA and BPF Gallet-Ayala et al. method1 was used as a starting point Optimization of the CE buffer was neededThe buffer comprised of SDS (sodium dodecyl sulfate) and phosphate

adjusted to pH 2.5After multiple trials and increasing concentrations of SDS, an optimum

buffer concentration was obtained for timely separation of BPA and BPF (Figure 2 & Table 1)

ExperimentalNeat Calibration StandardsFive BPA standards were prepared ranging from 200-900 ppb BPAEach standard was prepared from a 1000 ppb BPA stock solution and

diluted with 18 MΩ H2OEach standard contained 50 µL of dilution buffer (Table 1) Sample PreparationBPA was leached from baby bottles according to the flow chart2

The boiling water bath was placed in a shaker to ensure full BPA exposure to the water sample within the bottles

Key steps for this procedure are shown in Figures 3-5Total leaching/extraction procedure took 6 hStandard Addition Standards36 standard addition standards were prepared (3 real replicates for both

China and Indonesia bottles)Known BPA concentration ranged from 0-500 ppbEach standard also included 50 µL of dilution buffer, 100 µL sample,

and the remaining diluted with 18 MΩ H2OTable 2: CE Beckman P/ACE MDQ Capillary Electrophoresis System Instrument Parameters

DiscussionThe qualitative separation of BPA and BPF was

achieved (Figure 2) The quantification of BPA within the baby bottle

samples was also determinedThe leaching process followed was effective in

extracting the BPA from the samplesStandard addition was found to be the most

advantageous technique to determine quantitative results for such low concentrationsat ppb level

The BPA levels found were below the BPA threshold, but still raise concern with regards to infants

Data and Results

Thank you to Dr. Kingsley Donkor and to Laiel Soliman for all of their continuous support, knowledge, and wisdom.

Acknowledgements

Conclusions The method developed for BPA detection and quantification using

capillary electrophoresis was successful Both types of feeding bottles were determined to contain BPA The bottles from Indonesia appear to leach a significantly higher

amount of BPA compared with the bottles from China Quantification of BPF within the bottles has not yet been completedThe method is not yet flawless for the detection of BPA and BPF, and

future work is needed

Future Work Continued replication of this method is needed to confirm any

results found to date. Collect more data to give full certainty of concentrations determined.

Continued work adjusting the method for the separation of BPA and BPF within a sample

Analysis of other samples, aside from baby bottles, such as foodcontainers (canned tomato soup and paste)

References 1. Gallart-Ayala, H.; Nunez, O.; Moyano, E.; Galceran, M. T.

Electrophoresis, 2010, 1550-1559

2. Lateef, S. S. Agilent Applications, 2011, 1-11

Table 3: Calibration and standard addition curve data

Curve Type Equation R2

Neat BPA Calibration y = 3.3344x + 166.95 0.9948

Indonesia Sample Standard Addition y = 0.9301x + 268.56 0.9661

China Sample Standard Addition y = 1.3373x + 225.17 0.9560

Table 4: BPA concentrations determined for each baby feeding bottle

Sample[BPA]found µg/kg bw

Country ppb avg 12 month infantIndonesia

(150 mL bottle) 9.62 0.145China

(250 mL bottle) 3.37 0.084Table 1: Optimum Buffer Optimum Concentration (mM)

Buffer Component mM, diluted with 18 MΩ H2OSeparation/Rinse Buffer Sample Dilution Buffer

SDS 75 150Phosphate Buffer

(pH 2.5) 25 25

Figure 3: Solid Phase Extraction Apparatus

Figure 1: Structures of BPA and BPF

Figure 2: BPA and BPF optimized CE separation electropherogram

Figure 4: Ice bath to cool samples post-

leaching

Figure 5: N2 Gas Evaporation Apparatus

Figure 6: Beckman Coulter P/ACE MDQ CE with samples loaded

Figure 7: CE Standard Addition BPA electropherogram

Capillary Fused silica, 50 µm O.D. x 50 cm total length (40 cm to detector)Operating Temperature 25°C

Detection UV, 214 nm (indirect)Rinse pressure 20 psi: 3.0 min (0.1 M NaOH), 2.0 min (Water), 5.0 min (Buffer)

Injection of Sample Pressure, 0.5 psi for 15.0 sSeparation voltage + 25 kV

Separation time 10 min, 0.17 min ramp time

Minutes

4.6 4.8 5.0 5.2 5.4 5.6 5.8 6.0 6.2 6.4 6.6 6.8 7.0 7.2 7.4 7.6 7.8 8.0

AU

0.0006

0.0008

0.0010

0.0012

0.0014

0.0016

0.0018

0.0020

Minutes

16.4 16.6 16.8 17.0 17.2 17.4 17.6 17.8 18.0 18.2 18.4 18.6 18.8 19.0

AU

-0.03

-0.02

-0.01

0.00

0.01

0.02

0.03

0.04

BPA

BPF