Determination of Adsorbed Ethylene and Propylene Oxides by Distillation and Titration.

Abstract

the solution being titrated is made 12M in chloride ion, the decomposition rate is diminished to 0.3% per minute, but almost no chlorination of benzamide was noticed after 30 minutes. Bromine was also substituted for chlorine, but no ,IT-bromination was noticed in a reasonable time period.The following technique was then developed to eliminate errors due to the slight instability of the chlorinating agent. A direct titration was carried out, but the first experimental point after the end point was taken with only a ilight excess (usually about 25y0) of hypochlorite. The remaining points, which determined the second segment of the titration curve, were then assumed to be constant if the current decreased less than 1 pa. per minute.This procedure can be used successfully for primary aliphatic amides and for aromatic amides which are not substituted or which are substituted only with alkyl groups. The presence of other functional groups substituted on the aromatic ring in general causes interference in the determination of the amide group.Electron-withdrawing groups such as nitro and carboxyl reduce the rate of N-chlorination, and also adversely affect the equilibrium constant. Electron-donating groups activate the ring so that chlorination of the ring takes place readily, and the exact stoichiometry of the titration reaction becomes uncertain. In addition, substituted groups such as amino, carbonyl, and hydroxy are easily oxidized by hypochlorous acid in the titration medium.Preliminary experiments indicate that a possible solution to this problem of interference by ring substituents is exhaustive bromination in acid solution. If the unknown sample is treated w-ith bromine, most of the ring sites which would ordinarily be chlorinated during the titration are brominated. Also, easily oxidizable groups are oxidized by the bromine, and the excess bromine can then be driven off by heating. t-nder these conditions bromination on the amide nitrogen does not take place.

Determination of Ethylene Oxide, Ethylene Chlorohydrin, and Ethylene Glycol by Gas Chromatography

“…Several analytical methods have been reported in the literature for the determination of ethylene oxide (25)(26)(27)(28)(29)(30)(31)(32)(33), ethylene glycol (27,34), and ethylene chlorohydrin (35)(36)(37)(38)(39). However, the present analytical requirements with respect to sensitivity, specificity, and time of analysis for the quantitative determination of ethylene oxide, ethylene chlorohydrin, and ethylene glycol in water-absorbable fabrics did not readily adapt to these methods.…”

GLC Determination of Ethylene Chlorohydrin following Co‐Sweep Extraction

“…Numerous researchers have reported on various aspects of ethylene oxide sterilization. Until 1965, the only residues found from the use of this epoxide were ethylene oxide per se, ethylene glycol, and diethylene glycol (1)(2)(3)(4)(5)(6)(7)(8). Wesley et al (9) showed that chlorohydrins could be formed in foods fumigated with ethylene oxide or propylene oxide in the presence of inorganic chloride, Methods for analyzing ethylene oxide-sterilized foods, plastic, and rubber materials for residual ethylene chlorohydrin (Zchloroethanol) were reported by various researchers (10)(11)(12)(13)(14)(15)(16)(17).…”

Toxicological Studies on Certain Medical Grade Plastics Sterilized by Ethylene Oxide

“…The introduction of gas sterilization of plastics has raised questions as to the possible entrapment of ethylene oxide in a plastic, which may cause a toxic effect when placed in contact with living tissues, and the effect sorbed ethylene oxide will have on possible changes in the physical-chemical properties of the medical plastic. It has been demonstrated (5) that higher concentrations of the epoxide can be taken up by polyethylene, gum rubber, and plasticized polyvinyl chloride (PVC) which reemphasizes the problem of gas entrapment in plastics. Hirose et al (2) and Clarke et al (3) have found that plastic tubings which have been ethylene oxide sterilized can cause significant hemolysis when placed in contact with human blood.…”

“…The samples were analyzed by a procedure previously described by Gunther (5). Prior to milling each film, the rollers were carefully cleaned with practical grade stearic acid.…”

“…Prior to milling each film, the rollers were carefully cleaned with practical grade stearic acid. The bottle was then removed from the bath and titrated rapidly with a standardized HBr-glacial acetic acid reagent according to the method described by Gunther (5). During the final phase of the operation, the separation of the rollers was adjusted so as to furnish films having thicknesses in the range of 0.040-0.045 in.…”