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Part
2
Analysis of bisphenol A in animal feeds [Outline]
Animal feed samples cleaned up using an alumina A cartridge and
a polymer gel-filled cartridge are analyzed by a high
performance liquid chromatograph/mass spectrometer (LC/MS)
qualitatively and quantitatively1, 2.
[Reagents]
Confirm by chromatography that all the reagents present no
problem in bisphenol A (BPA) analysis.
(i) Standard samples: Environmental analysis grade BPA and
BPA-d16, and 13C-BPA supplied by Cambridge Isotope.
(ii) Standard BPA solution: Place 100 mg standard BPA in a
100-ml measuring flask, and dissolve by adding methanol to
obtain a concentrated standard solution of 1000 μg/ml. Prepare
appropriate standard solutions by diluting the concentrated
standard solution.
(iii) Internal standard solution: Place 10 mg BPA-d16 in a 50-ml
measuring flask, and dissolve by adding methanol to obtain a
concentrated standard solution of 200 μg/ml. Add the internal
standard solution to the standard and sample solutions to a
temporary concentration for measurement of the sample and
standard solution by LC/MS.
(iv) Cartridges for purification: Alumina-A cartridge (500 mg)3.
Wash the cartridge with 5 ml acetone before use. Wash the
polymer gel-filled cartridge4 with 10 ml methanol and then 5 ml
water before use.
(v) Pure water: Milli-Q water hardly contaminated by BPA.
Other reagents should be of the special grade or HPLC grade5.
[Tools]
Test the tools for sampling and sample preparation5 beforehand
for the materials, and choose ones with as little BPA release as
possible. Heat glassware to 350℃ for at least two hours, let
cool down in a place free from BPA contamination from the
environment, and wash with acetone immediately before use.
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