Plastics extractives

Part 20 Determination of epichlorohydrin in plastics Extraction of epichlorohydrin with dioxane, followed by microdistillation and derivitization with 9,10-dimethoxyanthracene-2-sulfonic add followed by reverse phase HPLC with fluorescence detection... 

El-Abbes Faouzi et al. [77] studied the stability, compatibility and plasticizer extraction of miconazole injection added to infusion solutions and stored in polyvinyl chloride containers. The stability of miconazole in various diluents and in... 

Precautions should be taken when selecting various vessels of differing materials for the extraction of these steroids from their matrices. For example, the compatibility of some solvents with plastic extraction tubes may present some problems. If glass vessels are to be selected, it is recommended that all glassware is silanized prior to use since several steroids bind to glass surfaces. 

Faouzi, M. A., Khalfi, F., Dine,T.,Luyckx, M., Brunet, C., Gressier, B., Goudaliez,F., Cazin, M., Kablan, J., Belabed, A., and Cazin, J. C. (1999), Stability, compatibility and plasticizer extraction of quinine injection added to infusion solutions and stored in polyvinyl chloride (PVC) containers,/ Pharm. Biomed. Anal., 21, 923-930. 

Because of the many different plasticizers, it frequently becomes important to analyze the composition of a plasticizer extracted from a plastic. A chromatographic method has been developed for analyzing plasticizers by D. Braun and is described in his chapter. 

The list of potentially hazardous materials includes drugs, food additives, preservatives, ores, pesticides, dyes, detergents, lubricants, soaps, plastics, extracts from plant and animal sources, plants and animals that are toxic by contact or consumption, and industrial intermediates and waste products from production processes. Some of the information refers to materials of undefined composition. The chemicals included are assumed to exhibit the reported toxic effect in their pure state unless otherwise noted. However, even in the case of a supposedly pure chemical, there is usually some degree of uncertainty as to its exact composition and the impurities that may be present. This possibility must be considered in attempting to interpret the data presented because the toxic effects observed could in some cases be caused by a contaminant. Some radioactive materials are included but the effect reported is the chemically produced effect rather than the radiation effect. 

The principal concerns with the biocompatability of polymers are additives, residual monomers, and contaminants that are leachable in the body. Plastic extractables include such chemicals as base polymers, fillers, lubricants, plasticizers, antioxidants, pigments, and slip agents. They may also include reaction... 

Waugh, W.N. Trissel, L.A. Stella, V.J. Stability, compatibility, and plasticizer extraction of taxol (NSC-125973) injection diluted in infusion solutions and stored in various containers. Am.J.Hosp.Pharm., 1991, 48, 1520-1524 [stability-indicating simultaneous degradation products injections 5% dextrose saline]... 

A simpler, lower cost technique which can readily separate the antioxidants from plastic extracts and give a qualitative analysis is thin layer chromatography (BS6630, 1985). In thin layer chromatography (TLC), the stationary phase is comprised of a thin layer of adsorbent such as cellulose, alumina, or silica gel on a plastic sheet, thick aluminium foil, or a glass plate. A small spot of solution containing the sample is applied to a plate, about 1 cm from the base. The plate is then placed in a sealed container which holds a suitable solvent, such as ethanol, so that it does not come into contact with the spots. The solvent moves up the plate by capillary action and meets the sample mixture, which is dissolved and is carried up the plate by the solvent. Components in the sample mixture travel at different rates due to differences in solubility in the solvent, and due to differences in their attraction to the plate. 

Uses Prod, of chlorodifluoromethane (a refrigerant and propellant), fluorocarbon plastics extraction solvent for pharmaceuticals, nat. oils solvent for perfume analytical chemistry intermediate in prep, of dyes, drugs, pesticides fumigant insecticides ingred. in drugs and cosmetics preservative, solvent, flavor in pharmaceuticals in food-pkg. adhesives adjuvant for PC food-pkg. resins Features Sweet pleasant flavor... 

FIGURE 15.45 Decabromodiphenyl ether, congener BDE-209 (a) upper, total ion chromatograph showing detection of BDE-209 in an acrylonitrile butadiene styrene (ABS) plastic extract (a) lower, product ion mass spectrum of BDE-209 showing the loss of Brj from each of the ions of the molecular ion cluster (b) %RSD in the chart is obtained from raw peak area data for a standard solution run after 10 injections of the ABS extract. 

Re.si.stance to extraction. If a polymeric material comes into contact with liquids (water, solvents, oil) the probability of plasticizer extraction increases. Plasticizer molecule size, the concentration of plasticizer, polymer-plasticizer compatibility, and temperature are essential parameters controlling potential for extraction. An incompatible plasticizers can be extracted almost completely in matter of hours. 

Figure 13.8 shows dependence of the ntigration rate of the plasticizer from PVC into sunflower oil on the chemical structure of the plasticizer. The rate of ntigration depends on the plasticizer and the food simulant. For example, DOP had a very similar rate of ntigration into three tested simulants (sunflower oil, isooctane, and ethanol). Migration of TOM into sunflower oil was shown already to be faster than DOP but it is still slower than its ntigration into isooctane. Compatibihties of plasticizer, extractant, and matrix polymer affect the rate of ntigration. 

The specified conditions in the plastics extraction test and the standard extractants prescribed by different authorities differ considerably. As an example, the extractants quoted by the British Plastics Federation [1] and the US Food and Drug Administration [2, 3] are given in Table 20.2. 

Caution Some plastic tubing, including polyvinylchloride (PVC), may have its plasticizer extracted by the solvent and deposited on the surface being cleaned. For this same reason, rubber, neoprene, and nylon tubing should not be used with these solvents when cleaning oxygen equipment. Polyethylene, polypropylene, and polytetrafluoroethylene (PTFE) tubing are satisfactory with the frequently used solvents. 

Relative purity measured by LC-UV or LC-ELSD is higher than quantitative purity determined by weight percentage of the compound. This suggests that there are undetectable impurities in the sample. These may include inorganics, TFA, plastic extracts, solvents. 

The de-plasticized (extracted or otherwise) cells are then packaged into vapor-impermeable, flexible, multilayer polymer-aluminum bags, dried under reduced pressure and elevated temperature to remove any adsorbed water, activated with a measured amount of liquid electrolyte solution, and sealed. The liquid electrolyte is rapidly absorbed into the microporous structure of the electrodes and separator, thus making the spillage of the liquid electrolyte from an open battery highly improbable. 

In the presence of fuels, polyamide 12 swells with increases in volume and length until it reaches equilibrium. If the polyamide is plasticizer-modified, swelling proceeds faster initially and then decreases again because of plasticizer extraction. Figure 5.334. 

The largest class of polymeric plasticizers is polyesters, which are prepared by the reaction of differing diols, dibasic acids (such as adipic acid or phthalic anhydride), and an aliphatic primary alcohol or an aliphatic acid acting as a chain stopper to help control the molecular weight. These products typically range from high viscosity liquids to gels or semisolids at room temperature. Polymeric plasticizers offer improved performance in resistance of plasticizer extraction by solvents or oils, resistance to... 

The specified conditions of the plastic extraction test and food simulating extraction solvents prescribed in the test by various authorities differ considerably. As an example of the type of test procedure recommended, those of the European Union (EU) and those of the Food and Drug Administration (FDA) of the USA are discussed next in some detail as examples of procedures which receive recognition in countries other than the country of origin. 

Use 6 ml/25 ml portions of the twenty ether extracts for calibration on the infrared procedure. Dilute each of the extracts (ether removed) up to 10 ml with spectroscopic grade carbon tetrachloride, and measure the absorbance (in a 1 mm path length rock salt cell) of the carbonyl peak occurring at 575 nm, as described previously. Prepare a calibration graph for each of the four extraction liquids by plotting determined absorbance (A) versus ppm DLTDP added to 800 ml of original extraction liquid (i.e., between 0 and 94 ppm w/v). Use this calibration graph to determine the DLTDP content of plastic extraction liquids of unknown composition. 

In view of the evidence concerning the possible degradation of DLTDP during the analysis, it is desirable to apply the same treatment to the standard DLTDP calibration solutions as applied during the analysis of plastic extraction liquids of unknown DLTDP. This would cancel out errors in the analysis caused by partial degradation of DLTDP. To calibrate the procedure, various standard concentrations of DLTDP were made up in each of the extractants, which were then heated for 10 days at 60 °C. The aqueous extractants were then ether-extracted and the extracts used to calibrate the Schoniger combustion and the infrared procedures. 

The azeotropic-distillation procedure cannot be applied to this alcoholic extraction liquid. Transfer 16 ml of the aqueous alcohol plastic-extraction liquid and 16 ml of the blank alcoholic extraction liquid into two 25 ml stoppered graduated cylinders. To each cylinder add 2 ml of 0.2 M TMAI and 2 ml of distilled water and mix. Examine these solutions polarographically as described previously. 

The amount of acrylonitrile in the plastic-extraction liquid, ppm w/v, is given by ... 

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