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Objective@#To optimize the membrane filtration method for hepatitis A virus concentration from mimicked water samples.@*Methods@#Mimicked water samples containing HAV particles were prepared and concentrated by positively charged membrane and negatively charged membrane respectively. Then different method including direct lysis, shaker, vortex and ultrasonication were used to elute HAV followed by the quantification of HAV by Taqman Real-time RT-PCR. The data were analyzed by professional statistical software.@*Results@#In the present study, when mimicked water samples contained 300 TCID50 of HAV, there was no significant difference between the concentration effects by negatively charged membrane and positively charged membrane (P=0.825>0.05). However, when HAV in mimic water samples was up to 1500 TCID50 and 7500 TCID50, the recycle efficiency by negatively charged membrane was higher than that by positively charged membrane (P<0.01). Additionally, this study found that HAV recycle ratio could be up to (68.17±16.79)% when direct lysis was used for viral elution, therefore direct lysis was proved much better than shaker, vortex and ultrasonication. They were significantly different (P<0.0001).@*Conclusions@#Elution process played the key role in HAV concentration when membrane filtration method was used. Direct lysis was proved much better than other method and it was the most efficient way in HAV recycle from mimicked water samples.
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The environmental organic pollutant of di-2-ethylhexy phthalate ( DEHP ) was analyzed by extractive electrospray ionization mass spectrometry ( EESI-MS ). Effect of some important experimental conditions were investigated systematically, including the electrospray voltage, temperature of ion-transport tube, sample injection rate and extractant composition. Under the optimal conditions, a method for rapid detection of DEHP in water sample was established. DEHP levels in different samples with complex matrixes were measured, including landfill leachate, urban sewage and lake water. The results showed that DEHP in water samples could be ionized by EESI source and obtained the molecule ion (m/ z 391. 28) at the positive detection mode, and then CID experiment were performed to obtain the secondary fragment ions m/ z 279. 26, 167. 12 and 149. 11. The intensity of characteristic peak m/ z 149. 11 possessed a good linearity with the concentration of DEHP in the range of 5-1000 μg / L with the correlation coefficient of R2 = 0. 9991, and the detection limit (LOD) of 0. 21 μg / L. The recoveries of DEHP at three spiked levels (8, 80, 400 μg / L) were 96. 2％ - 111. 2％ , with RSDs of 5. 6％ - 11. 8％ . With the developed EESI-MS method, the concentrations of DEHP in landfill leachate, urban sewage and Yan lake water were 556. 5, 275. 3 and 37. 8 μg / L, respectively. The EESI-MS method possessed many advantages such as no requirement of sample pretreatment, fast analysis speed ( about 3 min per sample), simple operation and high sensitivity, thus providing a new mass spectrometric method for rapid detection of phthalate esters.
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Bacteriological examination of water is one of the most important areas of investigation because upto 80% of all sickness and diseases in the world are water related. Heterotrophic bacteria are the least studied indicator for water quality determination. The present investigation encompasses two different approaches to estimate water quality.e.g a) to modify the conventional culture media for maximal recovery of heterotrophs and b) to assess the load of the total aerobic heterotrophs as an indicator from drinking and surface water. Six samples from different sources were examined with nine different media such as NA, MNA, PCA, PCA-6, SDA-8, R2A, SE, SOE, and SSE for comparative evaluation. Among them,SE,SOE and SSE are newly formulated media using soil extract, soybean extract and the combination of both of them respectively.SDA-8 was found to be superior in most cases in relation to its comparative efficiency.SSE medium was also found to be superior in case of two samples. The range of heterotrophic bacterial count on different media varied from 3.0 x104 cfu/100ml to 8.6x 105 cfu/100ml and 9.5x106 cfu/100ml to 7.5x107 cfu/100ml in case of drinking water and surface water respectively.
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Study of long and short-term impact of hydro-meteorologically induced extreme flood on groundwater from well is a baby science, yet to grow and groom. This article focuses on the environmental impacts of the worst Pakistani floods on water quality of affected areas, Charsadda and Nowshera districts in Khyber Pakhtunkhwa province which experienced a disastrous flood in its record due to torrential monsoon rains in late July 2010. For this purpose, consuming water products from 10 main sources (tube wells), 10 intermediate points in water supply distribution system and 10 consumers’ ends in 30 selected sites of flood affected areas were collected and analyzed for 12 key factors. Most of the parameters with respect to the standard limits of WHO guidelines indicated contamination in all samples that are directly available from tube wells as well as the one supplied through damaged pipe distribution system. This result becomes more fatal in the presence of microbial contamination and makes water risky for domestic consumption. A concrete policy addressing post-flood environmental effects on life and human health should be devised and strictly followed. Individual cases must be assessed from a basinwide perspective in order to make sure that environmental concerns are judiciously and properly represented in flood planning and risk management decisions.
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A method for the analysis of five types of triphenylmethane dye residues in water was developed by using solid phase extraction ( SPE) combined with ultra performance liquid chromatography coupled to triple quadrupole linear ion trap mass spectrometry ( UPLC-MS/MS/MS ) . The water samples were extracted and cleaned with mixed-mode cation exchange solid-phase extraction cartridges ( MCX) . The UPLC separation was performed on a C18 column with a linear gradient elution program of acetonitrile and 5 mmol/L aqueous ammonium acetate ( containing 0. 02% formic acid) as mobile phase. Triphenylmethane dye residues were analyzed by mass spectrometry under an electrospray ionization interface ( ESI ) in positive ion mode with MRM-IDA-EPI mode. The calibration curves of five types of triphenylmethane dyes were linear in the range of 0. 02-20 μg/L, and the correlation coefficients were not less than 0. 998. The recoveries at spiked levels of 5 , 10 and 20 μg/L were in the range of 70 . 9%-101%, and the RSDs were 3 . 4%-11 . 9% ( n=6 ) . The limit of detection and quantification were 0. 42-2. 18 ng/L and 1. 68-8. 73 ng/L, respectively. The method was performed as sensitive and accurate, and also suitable for simultaneous determination of five types of triphenylmethane dye residues in water.
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A high performance liquid chromatography tandem mass spectrometric ( HPLC-MS/MS ) method was developed for the determination of seven perfluorinated alkyl acidin ( C4-C10 ) and perfluorooctane sulfonate in water. After the particulate was removed by leaching, surrogate standard was added, then the sample was loading to a pre-conditioned WAX cartridge for purification, and then the eluent was concentrated and analyzed by HPLC-MS/MS. Due to the situation that the fluoride polymer was unavoidable to be used in the LC system, a delay column was employed and the perfluorooctanoic acid ( PFOA ) of interference was departed from the PFOA in sample. The method detection limit ( MDL) of PFOA was 0. 8 ng/L, and the lowest quantitative concentration (LQC) was 3. 2 ng/L. For other compounds, the MDL was ranged from 0. 2 to 1. 2 ng/L, and the LQC was 0. 8-4. 8 ng/L. This method also had good reproducibility, for six duplicated samples, the relative standard deviations ( RSD ) of all target compounds were less than 16%. And the recoveries of target compounds at six spiked matrix samples ranged from 87% to 129%, and the RSD were less than 15%. Because of the connection of delay column, the background was well controlled, and a relatively lower MDL were obtained.
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Introduction: Diarrhoea caused by contaminated water is among the most prevalent waterborne diseases in the developing countries like India. In the interest of public health, water supplies should be tested regularly to confirm their freedom from contamination. Objective: The objectives of the study were to screen different water sources for bacterial contamination, to know the antibiotic susceptibility of the common bacterial isolates and typing of the bacterial isolates by random amplification of polymorphic DNA (RAPD) technique. Place and Duration of the Study: Kasturba Medical College Hospital, Microbiology Laboratory, Mangalore, Karnataka, India between August 2007 and August 2009. Methodology: Water samples (n=324) were analyzed by standard microbiological techniques for bacterial contamination. Isolates were identified biochemically and antibiotic susceptibility testing was done by disc diffusion method. Escherichia coli isolates were typed by RAPD technique. Results: Among the water samples tested, 246 were excellent and 78 were contaminated. Contaminated samples showed the growth of commensal bacteria belonging to the family Enterobacteriaceae along with pathogens like Salmonella spp. and Vibrio spp. Many of the isolates were found to be sensitive and a few were found to be resistant to the antibiotics tested. RAPD typing showed genetic similarity and differences among the E. coli isolates from different water sources. Conclusion: Genetic similarity among isolates of E. coli indicates a common ancestral origin or a common source. Bacterial contamination of water samples with pathogens like, Salmonella spp. and Vibrio spp. as well as the faecal coliform is a concern, as water quality is an index of health and well - being of the society. Degree of contamination observed in this study suggests a need to be vigilant to monitor water quality, in order to prevent enteric diseases.
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Analysis of heavy metals of water samples from Tube wells, Ring wells, Ponds and Rivers were carried out during year 2008 and 2009. Samples were analyzed using standard methods. To assess the quality of drinking water, each parameter was compared with the standard desirable limit of that parameter in drinking water as prescribed by different agencies. The results from the analysis of water show that the highest PH was recorded in premonsoon season, but lowest value recorded in monsoon season. All the sources have PH within the maximum limit. The copper and zinc concentrations in all sources were below the permissible limit but in case of nickel all the sources have its value exceed the limit. Chromium was detected during post monsoon and winter seasons. Two sources have chromium values exceed the permissible limit. In the present study, maximum amount of arsenic in all seasons is recoded from Ring wells only. The statistical parameters such as Mean, Variance, Standard deviation (SD) and Coefficient of variation (CV) were calculated. Correlation Coefficient Matrix among the parameters was calculated and correlations between various parameters were worked out. Significant positive and negative correlations among the parameters were determined.
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The aim of this study was to apply a molecular protocol to detect leptospiral DNA in environmental water samples. The study was carried out in a peri-urban settlement in Petrópolis, state of Rio de Janeiro. A multiplex PCR method employing the primers LipL32 and 16SrRNA was used. Three out of 100 analysed samples were positive in the multiplex PCR, two were considered to have saprophytic leptospires and one had pathogenic leptospires. The results obtained supported the idea that multiplex PCR can be used to detect Leptospira spp in water samples. This method was also able to differentiate between saprophytic and pathogenic leptospires and was able to do so much more easily than conventional methodologies.
Subject(s)
DNA, Bacterial/analysis , Leptospira/isolation & purification , Polymerase Chain Reaction/methods , Water Microbiology , Brazil , Leptospira/genetics , Poverty AreasABSTRACT
OBJECTIVE To observe the effect of flushing dental handpieces to prevent suction-induced contamination and to lower the bacterial level in dental unit waterlines,and then to analyze the time-effect relationship of flushing.METHODS Twelve BienAir handpieces(group A) and 12 W&H TA-96 handpieces(group B) were employed in this study.The water samples from each handpiece′s outlet were immediately taken once when operations of de-caries,cavity-preparing and dental-drilling had been completed,and then taken once per 0.5 min while the handpieces were being flushed by running without work for 4 min.The bacterial colony formation of these water samples was counted on R2A agar plates.Colony forming units vs flushing time were then compared.RESULTS Alike in groups A and B,water bacterial levels were lowered the most significantly while flushing the handpieces for 0.5 min.BienAir or W&H TA-96 handpieces still showed decreased levels of water bacteria when being flushed for 3 or 2.5 min respectively.Afterwards,the flushing effect reached to a platform,that was,more flushing time didn′t bring the bacterial level down further.CONCLUSIONS Flushing handpieces by running without work can significantly reduce the level of bacterial contamination in the waterlines.Different types of handpieces may have different flushing time at which the most effect is reached.
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Objective To establish a continuous flow analytical method for determination of potassium in environmental water sample.Methods The concentration of patassium in environmental water sample was determined by ALLIANCE auto-matic analyzer,and its data were compared with the data obtained from atomic absorption spectrophotometry.Results The de-tection limit of this method was0.5?g /ml.The method revealed linear relationship at the potassium concentrations of5-1000?g /ml.The recovery rate of standard addition method ranged from to97%to102%.The relative standard deviations were0.82%-1.23%.Conclusion The contents of potassium in environmental water samples could be accurately and rapidly deter-mined by continuous flow analysis.
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ve To establish a method of high performance liquid chromatography (HPLC) for determi-nation of nitrite in water. Methods The trace content of nitrite in water sample was determined by indirect UV-HPLC. The mixture of methanol/o-phthalic acid (pH value was adjusted to 8.6 by 0.10 mol/L NaOH solution)5: 95 was defined as mobile phase. The water sample was directly filtered by chromatographic column pack with ODP. Results Under the conditions of wave length of 270 nm and flow rate of 0.9 ml/ min, the linear range of this assay was 0.0~20.0?g/ml nitrite, the relative standard deviation was 3.9%. The average recovery rate and detection limit were 99.9% and 0.001?g/ ml respectively. Conclusion This method could be applied to the determination of trace amount of nitrite in drinking water, purified water and mineral water.