Bisphenol, detection

As to the main limitation of MS vs. FTIR detection, namely the inability to distinguish closely related isomers, this rarely plays a role in additive analysis. Notable examples of isomeric additives are the bifunctional stabilisers C22H30O2S as 4,4 -thio-bis-(6-t-butyl-m-cresol), 2,2 -thio-bis-(4-methyl-6-f-butylphenol) and 4,4 -thio-bis-(2-methyl-6-f-butylphenol) (Section 6.3.6), the bisphenolic antioxidants C23H32O2 (Plastanox 2246 and Ethanox 720) and the phenolic antioxidants C15H24O (nonylphenol and di-f-butyl-p-cresol). 

Polymer extracts are frequently examined using GC-MS. Pierre and van Bree [257] have identified nonylphenol from the antioxidant TNPP, a hindered bisphenol antioxidant, the plasticiser DOP, and two peroxide catalyst residues (cumol and 2-phenyl-2-propanol) from an ABS terpolymer extract. Tetramethylsuccino-dinitrile (TMSDN) has been determined quantitatively using specific-ion GC-MS in extracts of polymers prepared using azobisisobutyronitrile TMSDN is highly volatile. Peroxides (e.g. benzoyl or lauroylperoxide) produce acids as residues which may be detected by MS by methylation of the evaporated extract prior to GC-MS examination [258]. GC-MS techniques are... 

Yoon Y, Westerhoff P, Snyder SA, Esparza M (2003) HPLC-fluorescence detection and adsorption of bisphenol A, 17P-estradiol, and 17a-ethynyl estradiol on powdered activated carbon. Water Res 37 3530-3537... 

Monitoring of the PFR can be made spectroscopically because the photoproducts have well-defined absorbtion bands in the UV-visible and infrared (IR) ranges [232]. Fluorescence spectroscopy allows the early detection of phenyl salicylate-type products in the photolysis of bisphenol A-based polycarbonates due to the characteristic emission of this chromophore around 470 nm [233]. 

Numerous bisphenols of the general structure 10 were detected in both the ether and toluene extracts of the transalkylation products from the fresh and oxidized coal samples. 

Bisphenol A causes slight skin and eye irritation. It did not cause contact allergy in a guinea pig maximization test. Furthermore, no cross-reactions were detected when animals sensitized to the diglycidyl ether of bisphenol A were tested with bisphenol A. 

Using simple laboratory equipment, it is possible to detect variations of the density of the order of 1 kg m-3 therefore, density measurements would be useless for diglycidyl ether of bisphenol A and diamino diphenyl methane (DGEBA-DDM), because both components have close Ma values. They would be moderately sensitive for unsaturated polyesters of maleate/ phthalate (1/1) of propylene glycol crosslinked by styrene (36 wt%), and relatively sensitive for DGEBA cured by diamino diphenyl sulphone (DDS) or phthalic anhydride (PA), for which relative variations of the molar ratio y of about 5% could be detected. In certain cases, where some comonomer (PA or styrene) can be lost by evaporation during the cure, density measurements can constitute a simple and efficient method of control way (e.g., for non-filled materials). 

Results for endocrine disrupting phenols in house dust as reported by Rudel et al. (2003) and Butte et al. (2001) are compiled in Table 11.1. Rudel et al. (2003) sampled indoor air in 120 homes as well. They analyzed both house dust and air for 89 organic chemicals identified as EDCs. The most abundant compounds in air included 4-nonylphenol and 4-t-butylphenol with typical concentrations in the range of 0.050-1.500ggm 3. Saito, Onuki and Seto (2004) collected air samples from houses, offices, and outdoor points. 4-t-butylphenol, 4-t-octylphenol and 4-nonylphenol were detected in both indoor and outdoor air. Concentrations and detection frequencies were higher in indoor air than outdoor air. The maximum levels of 4-t-butylphenol, 4-t-octylphenol and 4-nonylphenol in indoor air were 0.387, 0.0457 and 0.680 ggm 3, respectively. 4-t-butylphenol and 4-nonylphenol were detected with high frequencies (more than 97%) in the indoor air samples. Wilson, Chuang and Lyu (2001) reported a mean of 0.0007 gg m"3 Bisphenol A in the air of 10 child care centers and a mean of 0.203 gg m 3 for the sum of nonylphenol and its ethoxylates. 

The other study on human cord blood collected in a Kuala Lumpur hospital (Benjamin Tan and Mustafa, 2003) reported that only chlopyrifos was found in 18% of the samples at levels of ND-1.15ng mL-1 while other pesticides analyzed, such as lindane, diazinon, endrin, and endosulfans were not detected. In the same study, bisphenol-A and nonylphenols were detected in more than 80% of the samples at concentration levels of ND-4.05 and ND-15.17ng mL-1, respectively. Several alkylphenols were also found in these blood samples. 

Matsumoto, K., T. Sakai, A. Torimaru, et al. 2005. A surface plasmon resonance-based immunosensor for sensitive detection of bisphenol A. J. Fac. Agric. Kyushu Univ. 50 625-634. 

Braunrath, R., D. Podlipna, S. Padlesak, et al. 2005. Determination of bisphenol A in canned foods by immunoaffinity chromatography, HPLC, and fluorescence detection. J. Agric. Food Chem. 53 8911-8917. 

Biedermann M. Grob K, Bronz M, Curcio R, Huber M and Lopez-Fabal F, 1996, Bisphenol-A-diglyci-dyl ether (BADGE) in edible-oil-containing canned foods determination by LC-LC-Fluorescence detection. Mitt. Gebiete Lebensm. Hyg. 87. 547-558. 

Sharman. M., Honeybone, C.A., Jickells, S.M., and Castle, L., 1995, Detection of residues of the epoxy adhesive component bisphenol A diglycidyl ether (BADGE) in microwave susceptors and its migration into food.. Food Add. Contam. 12,6,779-787. 

The bisphenol A contents of PVC stretch films for food packaging were investigated. Major components were identified by FTIR and horizontal attenuated total reflectance. Migration of bisphenol A from these materials was determined by HPLC using both fluorescence and UV detection. 33 refs. 

In the last few years, special attention has also been paid to the exposure of humans to bisphenol A (4 -dihydroxy-2,2-diphenyl, BPA Fig. 7.1), well-known for its estrogenic properties. BPA [28] is commonly used as an industrial plasticizer and is found in paints, flame retardants, unsaturated polyester resins, plastic food packaging, containers for water, infant feeding bottles, and foils used for food storage. Several studies have confirmed the presence of BPA, at a detectable level, in a wide variety of food containers [29-31]. Views on the potential danger... 

One of the main issues with concentration data is how the non-detectable (ND) values are treated. In many instances the substance(s) of interest is non-detectable in either food simulants or real foodstuffs. In a UK FSA survey (2000) for BADGE (bisphenol A diglycidyl ether) in caimed foodstuffs, in more than 95% (105 of III targeted samples tested) of the foodstuffs tested the levels were non-detectable. Using targeted foodstuffs in any surveillance will always skew any results to a higher level, in that only foodstuffs considered most likely to contain the substance will typically be analysed. 

Bisphenol A (chemically similar to MDA but having -OH groups rather than amine groups) was identified in the water and 3% acetic extracts from Sample 2. Bisphenol A was not detected in the extracts from Sample 1. Infrared transmission spectra recorded through Samples 1 and 2 showed that the MDl isocyanate was slower to react in Sample 2 and so the bisphenol A could possibly relate to the laminating adhesive. As a result, LC-MS tests were undertaken later in the research, on extracts from Sample 3 (laminated with the same adhesive) specifically looking for bisphenol A - none was detected. Tri-ethyl phosphate, thought to be used as a cure catalyst, was identified in the extracts from both Sample 1 and Sample 2. 

---