Extractability testing phthalates

Luks-Betlej et al. evaluated six different fiber materials for determination of seven different phthalates in water samples [56]. The tested phthalates included DMP, DEP, di-n-butyl phthalate (DBP), BBP, DEHP, di-n-octyl phthalate (DOP) and di-n-nonyl phthalate (DNP). All fibers investigated were favorable for the extraction of BBP. Low molecular weight phthalates (DMP, DEP, DBP) were best extracted by DVB/CAR/PDMS, DBP by CW/DVB and DEHP by PDMS fiber. CW/DVB fiber gave the best repeatability. Application of CW/DVB fibers to different water samples allowed the detection of... 

Brandt [200] has extracted tri(nonylphenyl) phosphite (TNPP) from a styrene-butadiene polymer using iso-octane. Brown [211] has reported US extraction of acrylic acid monomer from polyacrylates. Ultrasonication was also shown to be a fast and efficient extraction method for organophosphate ester flame retardants and plasticisers [212]. Greenpeace [213] has recently reported the concentration of phthalate esters in 72 toys (mostly made in China) using shaking and sonication extraction methods. Extraction and analytical procedures were carefully quality controlled. QC procedures and acceptance criteria were based on USEPA method 606 for the analysis of phthalates in water samples [214]. Extraction efficiency was tested by spiking blank matrix and by standard addition to phthalate-containing samples. For removal of fatty acids from the surface of EVA pellets a lmin ultrasonic bath treatment in isopropanol is sufficient [215]. It has been noticed that the experimental ultrasonic extraction conditions are often ill defined and do not allow independent verification. 

Si element ATR-FTIR spectroscopy was used to analyze this residue, and its spectrum, along with the closest library matches, are shown in Figure 41. The absorbance of this residue is low as a consequence of the thin layer present on the plate. This makes matching the sample spectrum with a reference spectrum somewhat difficult. The closest matches extracted from the library interrogated are to ester-based plasticizer materials, which is consistent with a phthalate-plasticized PVC. A more specific identification could have been made with further testing such as subjecting the residue to GC-MS analysis, but the information suggested by the ATR-FTIR analysis was, in this case sufficient. 

In a static-culture-flask screening test, diethyl phthalate showed significant biodegradation with rapid adaptation. The ester (5 and 10 mg/L) was statically incubated in the dark at 25 °C with yeast extract and settled domestic wastewater inoculum. After 7 d, 100% biodegradation was achieved (Tabak et al, 1981). 

Although pharmacopeial biological reactivity tests for containers are good indicators of the toxicity of extractables, there are species that do not cause an acute toxic reaction but rather a chronic reaction, as is the case of phthalates (DEHP) and metallic species such as aluminum. Moreover, there are species that are extract-able from packaging materials only by action of formulation constituents and therefore are not present in the extracts obtained by conventional pharmacopeial compendia tests. 

Diffusive samplers have also been developed to determine SVOCs but there have been relatively few studies to date. An example is the passive flux sampler developed by Fujii et al. (2003) to determine the rate of emission of phthalate esters from materials. The sampler consisted of a circular metal disc containing activated carbon particles held within an inert matrix of PTFE. The sampler was placed on the material under test giving a diffusion length of 0.5 or 2 mm depending upon the design and adsorbed phthalate esters were extracted from the sampler with toluene and determined by GC-MS. 

The organic phase contained (1) ethanol, (2) propanol, (3) methyl sulphide, (4) acetone, (5) propanol-2. (6) n-butanol, (7) butanone-2 and (8) carbon tetrachloride. Simultaneously, 0.4 ml of sodium bisulphite was added to 1 ml of the aqueous solution under test, and 15 min later the organic compounds were extracted with 3 ml of carbon tetrachloride. The extract was analysed by GC on a column of dinonyl phthalate at 80 C... 

One of the important requirements of any packaging material is that it should not release any component into the drug product. Preparation of containers free of any leachables such as monomeric component is especially important for the containers of ophthalmics, parenteral products, and any liquid products. It was shown that di(2-ethylhexyl) phthalate was released from the PVC bags and that caused haziness of the taxol solution (37), USP/NF offers the protocol of chemical, spectral, and water vapor permeation tests and tolerances for plastic containers (55). Among those, chemical test is designed to give a quantitative assessment of the extractable materials in both organic solvents and water. 

Crosslinked PBU [(VeA o) 0-20 kmol/m ] and crosslinked elastomer of butadiene-nitrile rubber SCN-26 [(VeA o) 0.07 kmol/m ] were used in this study. The tests were carried out at 25+0.10 C in the following mixtures n-nonane-tributyl phosphate (TBP), n-hexane-dibutyl phthalate (DBP), n-hexane-dibutyl maleate (DBM), and dioctyl sebacate (DOS)-diethyl phthalate (DEP). A crosslinked elastomer SCN-26 was immersed to equilibrate in amyl acetate-dimethyl phthalate mixture. Liquid phase composition was in range of 5 to 10%. A sol-fraction of samples (plates of 0.9x10 m diameter and in 0.3x10 m thickness) was preliminary extracted with toluene. 

Osman B, Ozer ET, Besirli N, Gucer S. Development and application of a solid phase extraction method for the determination of phthalates in artificial saliva using new synthesized microspheres. Polym test 2013 32 810-818. 

In case of printing paste, more than 5% w/w volatile organic compounds (VOCs) should not be permitted. These include acrylates, styrene monomers like acrylamide, butadiene, polyols, acrylonitrile, formaldehyde, hydrocarbons, ahphatic hydrocarbons (C10-C20), ammonia, etc. MSDS for printing formulation has to be supplied, and the testing can be done by solvent extraction and GC-MS methods. There is a restriction on the use of plastisols in printing binders and restricted phthalates including PVC. The threshold limit is 0.1%. 

It was found that isosorbide diesters are functionally comparable with the equivalent phthalates. Required properties, such as volatility, can be tuned by variation of the ester groups. Extensive testing in PVC formulations has shown that isosorbide diesters are primary plasticisers, are highly compatible with PVC, have good thermal stability, have excellent optical properties and have good migration/extraction characteristics. 

Nerin and co-workers [15] in their stndy of migration of various phthalate plasticisers from paper board into FDA extraction liquids used various test conditions including 10 days at 40 °C, 1 hour at reflux temperature for all aqueous stimulants, 10 days at 40 °C and 1 hour at 175 °C for olive oil and 2 days at 20 °C and 3 hours at 60 °C for the isooctane stimulant. 

Several studies have been conducted on the stability of selected plastics additives for food contact in EU aqueous, fatty and alternate stimulants. Thus, Simoneau and Hannaert [17] showed that bis(2-ethylhxyl)phthalate plasticiser and octadecyl 3-(3,5-di-ter -butyl 4-hydroxy phenyl) propionate antioxidant are quite stable under all heat exposure conditions tested (20-40 °C, 1 h to 10 days) and all food simulents used (15% ethanol, 95% ethanol, 3% acetic acid, olive oil and iso-octanol). In these tests, the amounts of additives remaining in the plastic at the end of the test were between 90% and 107% of the amounts present in the plastic before extraction. 

Methods for analysis of AE are well established. ASTM standard D4252 specifies determination of water by Karl Fischer titration, pH of a 1% aqueous solution, hydroxyl number by phthalation, and PEG by extraction, as well as other tests (19). NMR determination of ethoxy content is the subject of CTFA Method J 3-1 (96). 

Water solubility of each higher MW phthalate ester plasticizer for PVC is exceedingly low as is water extractability. Water typically removes plasticizer from flexible PVC sheet by invading the plastic and causing some plasticizer incompatibility. In theory, plasticizer on the surface of the film or sheet can be removed even without being dissolved in the water. [5] However, in a static test, plasticizer extractabilities from flexible PVC sheet by plain water are always somewhat lower than (but in the same relative direction as) plasticizer extractabilities by soapy water. 

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