ABSTRACT
@#COVID-19 has spread rapidly worldwide. The role of fomites in facilitating onward transmission is plausible. This study aimed to determine the presence of viable virus and its persistence on the surfaces of fomites in wards treating COVID-19 patients in Malaysia. This study was conducted in two stages. First, environmental sampling was performed on random days in the intensive care unit (ICU) and general wards. Then, in the second stage, samples were collected serially on alternate days for 7 days in two selected general wards. In Stage 1, a total of 104 samples were collected from the surfaces of highly touched and used areas by patients and healthcare workers. Only three samples were tested positive for SARS-COV-2. In Stage 2, three surface samples were detected positive, but no persistence of the virus was observed. However, none of the SARS-CoV-2 RNA was viable through tissue culture. Overall, the environmental contamination of SARS-CoV-2 was low in this hospital setting. Hospitals’ strict infection control and the compliance of patients with wearing masks may have played a role in these findings, suggesting adherence to those measures to reduce occupational exposure of COVID-19 in hospital settings.
ABSTRACT
A novel method for the determination of metallic elements in environmental samples was developed based on the matrix-assisted plasma surface sampling atomic emission spectrometry ( AES system) . A piece of filter paper was used as sample substrate. By direct interaction of the plasma tail plume with the filter paper surface, the filter paper absorbed energy from the plasma source and released combustion heating to the analytes originally present on its surface, thus to promote the atomization and excitation process. Surface sampling was performed in both cases of liquid and solid state analytes. Therefore, no flow injection system was required and sample pretreatment process was simplified. The proposed method provides several advantages, including fast analysis speed ( about 240 samples/h ) , little sample consumption (μL or μg level) , simplicity in instrument design, and also ease of system operation. These advantages made it attractive as a potential miniaturized AES system for in situ and high-throughput elemental analyses. Quantitative analysis of metal ions were achieved in this study for elements Ag, Au, Ba, Cd, Cr, Cu, Eu, La, Mn, Ni, Pb, Sr and Y. Under optimal conditions, the LOD values of the 13 elements ranged from 1. 0 to 88 μg/L. The repeatability, expressed as relative standard deviation ( RSD) from 10 replicates, ranged from 2. 3% to 6. 8%. To validate the proposed method, the system was employed to determine metal elements in standard reference materials of environmental samples. The content of each element was well in agreement with the certified values.