The present study aimed to evaluate the stability of Human Adenovirus type 2 (HAdV2) and Murine Norovirus 1 (MNV-1) in surface freshwater samples stored at different temperatures. For HAdV2 the stability decreased with increasing temperatures (−80 > −20 > 4 > 22 °C). The time required to reach one log reduction in viral titers (T90) was similar among all the times and temperatures by different cell-culture based methods and reverse transcription-quantitative polymerase chain reaction (RT-qPCR). The HAdV2 stability decreased with the time of storage temperature and methods employed, aside from samples stored at 22 and 4 °C which showed the lowest T90 values (50 days). For MNV-1, the samples stored at 22 and −20 °C showed higher log10 decay values, followed by 4 and −80 °C; while genome persistence was ranked as −80 > −20 > 4 > 22 °C. The T90 values were lower for samples stored at 22 °C (33 days), followed by 4, −20 and −80 °C with 111, 100 and 333 days, respectively. The results indicate that, under laboratory storage conditions, freshwater samples should be kept at 4 °C and at −80 °C for short- and long-term periods, respectively. This study provided useful information about thermal and temporal stability of the enteric viruses regarding sample storage conditions.
Sample preparation is the key to quality analysis with a laser analyser
Sample preparation is the most important step of any chemical analysis. To get the best results with any elemental alloy analyser regardless of the technology, the sample must be clean before taking a measurement. Otherwise the results are always compromised at least to some extent. The effect of dirty surfaces will vary and some technologies are more forgiving to sample surface conditions than others. How well an analyser can tolerate dirty surfaces depends on many variables such as the nature of physical...
Surface/bathing water monitoring (Denmark) - Case Study
In order to find the possible fecal sources to the sporadic high concentrations of bacteria, the municipality of Hjørring (DK) has set up a BACTcontrol in the ditch to monitor the E.coli levels.For this purpose the BACTcontrol is built into a movable trailer and powered by solar panels. This allows the BACTcontrol to run continuously (6 samples per day) for 7-14 days depending on the sunlight concentration.
Influence of surface modification by sulfuric acid on coking coal's adsorption of coking wastewater
Coking coal, the raw material of a coke plant, was applied to the adsorption of coking wastewater. In this study, coking coal was directly treated with sulfuric acid to improve its surface properties and adsorption ability. Acid treatment was carried out at various concentrations, by varying from 0.001 to 1 mol/L. The samples were characterized by ash content analysis, scanning electron microscope (SEM), N2 adsorption-desorption analysis, Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectrosc...
Nitrate Analysis of Water Samples Using a Benchtop UV-Vis Spectrophotometer
Nitrogen is naturally found in groundwater and surface water in the form of nitrate, nitrite, or ammonium. The EPA has established a maximum contaminant level of nitrate-nitrogen in potable water of 10ppm. This application presents results of UV-Vis analysis of nitrate concentrations in drinking water, ground water, and industrial wastewater, showing that the manual colorimetric method is suitable for analysis of nitrate contamination in water systems. The data included is part of a data set being used to...
World Oil: Holistic optimization approach improves coring efficiency, sample quality
To acquire a high-quality core in as few runs as possible, and reduce operational costs, a provider must maximize ROP while ensuring efficient, safe surface handling of the rock sample and coring assembly. To satisfy these requirements, HT30 Max, a full-gauge core barrel system with jam mitigation technology, has been introduced.To improve initial production and ultimate recovery, we must first fully understand the reservoir rock. Full-gauge coring is the first line-of-sight into a reservoir. The actual formation...