No abstract

A single peak is obtained at a rotating gold disc electrode for the anodic stripping of less than one monolayer of deposited Hg in 0.1 M HCI04. The peak at 0.9 V vs. SCE is resolved from the anodic wave for formation of the gold-oxide film. Differential pulse stripping voltammetry was applied for determination of Hg(ll) in the range 0.02-20 ppb.

Adsorbed iodine at a Pt electrode is demonstrated to be anelectrocatalyst for the irreversible electrochemical reduction of Cr(V1) in HCI and H2S04 solutions. Determination of Cr(V1) in a coulometric flow-through electrode is possible in the range 0.4 ng to 80 pg. No interference by dissolved 0, is observed. Application of the coulometrlc detector for chromatographic determinations of Cr(V1) Is presented.

BackgroundMultiple mobile ultraviolet (UV) light devices are available for disinfection of hospital rooms, but few data are available on the relative ability of devices to reduce surface contamination and ease of use. The objective of the present study was to compare the antimicrobial efficacy of several devices in a laboratory setting.MethodsUsing a modification of the ASTM International method E2197, spores of Clostridioides difficile(ATCC strain BAA-1870) suspended in phosphate-buffered saline (PBS) with 5% fetal calf serum were inoculated onto 20 mm stainless steel disks and dried. Disks were attached to right and left bedrails, under bed, call button, chair armrest, floor near device, table top, table bottom, floor far from device, toilet seat and grab bar and sink handle in a mock 6.4 × 4.1-meter hospital room with a 1.5 × 2.4-meter bathroom. Disks were exposed using cycle times and device placements recommended by device manufacturers. Spores from exposed disks and unexposed control disks were recovered in PBS with Triton X-100, enumerated using dilution plating, and log10reductions were determined by comparing the number of spores recovered from exposed and control disks. Times for set-up, treatment and resetting the space were recorded for each device. Results were expressed as mean log10reductions and percent reduction/minute of room vacancy. Results were compared using Kruskall-Wallis nonparametric analysis.ResultsMean log10reductions, percent reductions, run times for patient rooms and bathroom, setup/reset times, total room vacancy times, and percent reduction/minute of room vacancy are shown in the Table. There were no significant differences in percent reductions between different locations for each device. There were, however, statistically significant differences between microbial reductions between the different machines (P < 0.05 for all comparisons).ConclusionThere are many factors to consider in selecting a UV device. These considerations should include mean log10reduction, total vacancy times and percent reduction achieved/minute of room vacancy. Disclosures All authors: No reported disclosures.

No abstract