A capillary gas chromatographic method is described for the determination of cyclohexanone and 2-ethyl-1-hexanol leached from solution administration sets. A preliminary study was made of compounds leached from solution administration sets by 5% sodium bicarbonate solution (pH 8.1), 0.9% sodium chloride solution (pH 6.8), and water. Water was selected as the leaching solvent because similar quantities of the compounds were leached into water and into both types of parenteral solutions. The correlation coefficients were 0.99977 for cyclohexanone and 0.99974 for 2-ethyl-1- hexanol, and recoveries were good (93-94%). Five administration sets from each of 2 manufacturers were analyzed by this method. The amounts of cyclohexanone that were leached from the individual sets varied considerably; however, similar quantities were leached from sets of both manufacturers. 2-Ethyl-1-hexanol was also found in extracts from each of the sets analyzed.

Bacterial recovery by a portable Reuter centrifugal air sampler and a standard Mattson-Garvin slit-to-agar air sampler was compared in a series of experiments. Microbial air quality was monitored in seven typical laboratory locations. Tests showed that the Reuter centrifugal air sampler yielded significantly higher recoveries than did the slit-to-agar unit.

A study was made to determine the effects of temperature and moisture on the D-value of a common biological indicator. Relative humidity (RH) was varied between 10 and 70% in increments of 10%, and temperature was varied between 30 and 70 degrees C in increments of 10 degrees C. Temperature was found to have a pronounced effect on the D-value. At 60% RH, the D-value varied from 15.0 min at 30 degrees C to 1.1 min at 70 degrees C. When RH was plotted against the average D-value at the various temperatures, the temperature curves at or above 50 degrees C were more erratic and the RH had a significant effect. The study showed that temperature and RH must be controlled if biological indicators are to be properly calibrated for use in ethylene oxide sterilization.

No abstract

Three types of penicylinders were compared for their retention of spores of Bacillus subtilis testing for sporicidal activity of disinfectants. Glass, porcelain, and stainless steel penicylinders are inoculated with a water suspension of B. subtilis var. niger (ATCC 9372) spores and dried. One set of each type of penicylinder is submerged 1 h in 0.9% saline. One set of porcelain penicylinders is submerged 15 h in a neutralized chemical germicide, and one set is also inoculated with a culture filtrate of B. subtilis (ATCC 19659), dried according to the AOAC method, and submerged 1 h in 0.9% saline. Microbial loads simulate those held on carriers used to test sporicidal activity of disinfectants. Carriers are immersed in chemical germicide, transferred to a neutralizer, and placed in a culture medium. Average percentages of B. subtilis var. niger spores retained on 10 carriers after 1 h submersion in saline and in water were as follows: glass, 93.6%; porcelain, 99.9%; and stainless steel, 99.5%. Retention of spores after 15 h submersion in a neutralized chemical germicide and in water was 98.9%. Porcelain penicylinders inoculated from a culture filtrate of B. subtilis (ATCC 19659) retained 26% of the spores after being submerged 1 h in saline and placed in water. Glass penicylinders, which retained the lowest and most variable number of spores, were the least suitable for sporicidal activity testing. B. subtilis (ATCC 19659) spores tested on porcelain penicylinders met only the minimum HCI resistance requirements of ≥2 min. On porcelain penicylinders, the resistance of B. subtilis var. niger spores to 2.5N HCI was relative to the number of spores inoculated.