Quantification of Melamine in Drinking Water and Wastewater by Micellar Liquid Chromatography

2013 ◽  
Vol 96 (4) ◽  
pp. 870-874 ◽  
Author(s):  
Beatriz Beltrán-Martinavarro ◽  
Juan Peris-Vicente ◽  
Maria Rambla-Alegre ◽  
Sergio Marco-Peiró ◽  
Josep Esteve-Romero ◽  
...  

Abstract Because of the large potential health impact caused by deliberate contamination with the synthetic chemical melamine of different products for human and animal consumption, the World Health Organization and the Food and Agriculture Organization of the United Nations provided a range of recommendations in order to facilitate obtaining needed data, among which was the determination of the background levels of melamine in drinking water and wastewater (December 4, 2008). A chromatographic procedure using a C18 column, a micellar mobile phase consisting of sodium dodecyl sulfate (0.1 M), and 1-propanol (7.5%) buffered at pH 3, and detection by absorbance at 210 nm is reported in this paper for the quantification of melamine in drinking water and wastewater. Samples were filtered and directly injected into the chromatographic system, thus avoiding an extraction procedure. The optimal mobile phase composition was obtained by a chemometrics approach that considered the retention factor, efficiency, and peak shape. Melamine was eluted in about 6.2 min without interferences. Validation was performed following U.S. Food and Drug Administration guidelines. The analytical parameters studied were linearity (0.03–5 μg/mL, R2 = 0.998), LOD (13 ng/mL), intraday and interday accuracy (between 4.1 and 12.2%), intraday and interday precision (less than 14.8%), and robustness (RSD < 5.1% for retention time and <9.0% for area). The proposed methodology was successfully applied for analysis of local wastewater and drinking water, in which no melamine was found.

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Irena Malinowska ◽  
Katarzyna E. Stępnik

Micellar liquid chromatography (MLC) with the use of high performance liquid chromatography (HPLC) was used to determine some physicochemical parameters of six biogenic amines: adrenaline, dopamine, octopamine, histamine, 2-phenylethylamine, and tyramine. In this paper, an influence of surfactant’s concentration and pH of the micellar mobile phase on the retention of the tested substances was examined. To determine the influence of surfactant’s concentration on the retention of the tested amines, buffered solutions (at pH 7.4) of ionic surfactant—sodium dodecyl sulfate SDS (at different concentrations) with acetonitrile as an organic modifier (0.8/0.2 v/v) were used as the micellar mobile phases. To determine the influence of pH of the micellar mobile phase on the retention, mobile phases contained buffered solutions (at different pH values) of sodium dodecyl sulfate SDS (at 0.1 M) with acetonitrile (0.8/0.2 v/v). The inverse of value of retention factor () versus concentration of micelles () relationships were examined. Other physicochemical parameters of solutes such as an association constant analyte—micelle ()—and partition coefficient of analyte between stationary phase and water (hydrophobicity descriptor) () were determined by the use of Foley’s equation.


2021 ◽  
Vol 18 (1) ◽  
pp. 1-6
Author(s):  
Roselyn Naidu ◽  
Lionel Joseph ◽  
Syed Sauban Ghani

The current study investigated drinking water quality of samples taken from Arolevu village, a locality situated in Nadi, Fiji. The groundwater samples were collected and subjected to a comprehensive physicochemical and biological analysis. The analysis for the drinking water sample was conducted seasonally, six times a year, that is, three for the dry season and three for the wet season. The results retrieved from the analysis were compared to its maximum contamination levels (MCLs) based on the health-based guidelines provided by the World Health Organization (WHO). The WHO standards were used as an attribute to determine the sources of contaminants likely to be present at the study site. A degradation trend in drinking water quality in the context of climate change may lead to potential health impacts. Hence, it is important to understand seasonal variations in drinking water quality. A proper understanding of the drinking water quality through seasonal water analysis for nitrate, nitrite, potassium, calcium, magnesium and chlorine content as well as its microbiological presence to reduce preventable risks such as using calculated amounts of fertilisers and upgrading the sewerage system to alleviate drinking water contamination is devised through this study.


2013 ◽  
Vol 96 (6) ◽  
pp. 1315-1324 ◽  
Author(s):  
Mohamed I Walash ◽  
Fathalla Belal ◽  
Nahed El-Enany ◽  
Manal Eid ◽  
Rania N El-Shaheny

Abstract A stability-indicating micellar liquid chromatography (MLC) method was developed and validated for the assay of floctafenine (FLF) in the presence of its degradation product and main metabolite, floctafenic acid (FLA). The analysis was carried out on a CLC Shim-Pack octyl silane (C8) column (150 × 4.6 mm id, 5 μm particle size) using a micellar mobile phase consisting of 0.15 M sodium dodecyl sulfate, 10% n-propanol, and 0.3% triethylamine in 0.02 M orthophosphoric acid (pH = 3). The mobile phase was pumped at a flow rate of 1.0 mL/min with UV detection at 360 nm. The method showed good linearity for FLF and FLA over the concentration ranges of 0.5–25.0 and 0.4–10.0 μg/mL, with LODs of 0.16 and 0.12 μg/mL, respectively. The developed method was successfully applied to the determination of FLF in commercial dispersible tablets, with mean recovery of 98.87 ± 1.37%. Also, the proposed method was specific for the analysis of FLF in presence of the co-formulated drug thiocolchicoside in laboratory-prepared tablets, with mean recovery of 100.50 ± 1.07%. Statistical comparison of the results obtained by the proposed MLC method with those obtained by a comparison method showed good agreement. Moreover, the method was extended to study the degradation behavior of FLF under different International Conference on Harmonization recommended conditions such as alkaline, acidic, oxidative, thermal, and photolytic. The method was further applied for direct determination of FLA as the main metabolite of FLF in human plasma without prior extraction steps, with mean recovery of 110.50 ± 6.5%.


2015 ◽  
Vol 13 (4) ◽  
pp. 1073-1084 ◽  
Author(s):  
Nida Gul ◽  
Mohammad Tahir Shah ◽  
Sardar Khan ◽  
Nimat Ullah Khattak ◽  
Said Muhammad

The present study was conducted to investigate the physico-chemical characteristics in drinking water of Mardan District, Pakistan. Furthermore, water quality was evaluated for the risk assessment of arsenic and heavy metals (HMs) and their contamination sources. Representative groundwater samples of shallow and deep sources were collected in the study area. These samples were analyzed for physical parameters, anions, light metals (LMs) and HMs. Results were compared with the drinking water guideline values set by the World Health Organization and the US Environmental Protection Agency. Average concentrations of anions, LMs and HMs were found within the maximum allowable contaminant levels except for bicarbonates, Fe, Cu, and Pb. Results revealed that hazard quotients >1 were observed for shallow groundwater for 10% samples only, suggesting potential health risk from water consumption. Correlation analysis and principal component analysis showed a relationship among various physico-chemical parameters in both shallow and deep groundwater. Statistical analyses suggested the geogenic and anthropogenic sources for possible enhancement of various physico-chemical parameters in the aquifer system of the study area.


2012 ◽  
Vol 34 (2) ◽  
pp. 24-29
Author(s):  
Jeffery Deal

The United Nations Millennium Development Goal Number 7 states that it wants to "Halve, by 2015 the proportion of the population (global) without sustainable access to safe drinking water and basic sanitation" (United Nations 2010). Most waterborne diseases result in diarrhea, which continues to be a leading cause of morbidity and mortality worldwide. According to World Health Organization data, if existing technologies were widely used, ten percent of the worldwide burden of disease would be removed by the water supply, sanitation, hygiene, and management of water resources. This estimate makes water related diseases arguably the most manageable set of health problems affecting humans (Prüss-Üstün et al. 2008).


2021 ◽  
Author(s):  
Allison Portnoy ◽  
Kaja Abbas ◽  
Steven Sweet ◽  
Jane Kim ◽  
Mark Jit

Background: Cervical cancer is the second most common cancer among women in Ethiopia, India, Nigeria, and Pakistan. However, of these four countries, only Ethiopia has introduced human papillomavirus (HPV) vaccination at the national level in 2018 and India in a few states in 2016. Our study objective was to estimate the potential health impact of HPV vaccination among ten cohorts of 9-year-old girls from 2021-2030 in Ethiopia, India, Nigeria, and Pakistan using two independent mathematical models, and assess similarities and differences in vaccine impact projections through comparative modelling analysis. Methods: Using two widely published models (Harvard and PRIME) to estimate HPV vaccination impact, we simulated a vaccination scenario of 90% annual coverage among 9-year-old girls from 2021-2030 in Ethiopia, India, Nigeria, and Pakistan. We estimated the potential health impact in terms of cervical cancer cases, deaths, and disability-adjusted life years (DALYs) averted among vaccinated cohorts from the time of vaccination until 2100. We also conducted a comparative modelling analysis to understand the differences in vaccine impact estimates generated by the two models. Results: Prior to harmonising model assumptions, the range between the PRIME model and the Harvard model for the potential health impact of HPV vaccination in terms of the number of cervical cancer cases averted among girls vaccinated 2021-2030 between the year of vaccination and 2100 was: 262,000 to 270,000 in Ethiopia; 1,640,000 to 1,970,000 in India; 330,000 to 336,000 in Nigeria; and 111,000 to 133,000 in Pakistan. When harmonising model assumptions, alignment on HPV type distribution significantly narrowed the differences in vaccine impact estimates. Conclusions: The main difference in estimates for cases, deaths, and DALYs averted by vaccination between the models are due to variation in interpretation around data on cervical cancer attribution to HPV-16/18; differences in estimates for DALYs averted are additionally due to differences in age-specific remaining life expectancy over time between the two models. As countries make progress towards the World Health Organization targets for cervical cancer elimination, continued explorations of underlying differences in model inputs, assumptions, and results when examining cervical cancer prevention policy will be critical.


2012 ◽  
Vol 9 (1) ◽  
pp. 443-450 ◽  
Author(s):  
Hoonka Subhra ◽  
Bose Devasish ◽  
Esteve-Romero Josep ◽  
Durgbanshi Abhilasha

A simple chromatographic procedure is reported for the determination of some less prescribed but equally important benzodiazepines (Clotiazepam, clozapine and pinazepam) in serum. The optimization studies have been made in CN, C18and C8columns, using mobile phase containing sodium dodecyl sulphate (SDS) modified with either propanol, butanol or pentanol. The method proposed for the determination of the three benzodiazepines using a mobile phase of 0.13 M SDS, 2.4% pentanol-0.01 M phosphate buffer- 0.1% triethylamine (pH 7) at 25°C and UV detection (240 nm) in a C8column. The serum samples was injected directly, without any pretreatment, eluted in less than 8 min, in accordance to their relative polarities, as indicated by their octanol-water partition coefficients. The limits of detection (ng/mL) was in the 1.6 to 5.6 and 7 to 87 range, for aqueous and serum samples, respectively. Repeatability and intermediate precision was tested for three different concentrations of the drugs, resulting in the 0.1 to 2 range. The results obtained here for the separation of the three benzodiazepines in serum were also counter checked at Department of Bio-analytical Chemistry, Universitat Jaume I, Castelló, Spain.


2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Danielle Cristina da Silva ◽  
Cláudio Celestino Oliveira

Method for extraction and determination of amoxicillin, caffeine, ciprofloxacin, norfloxacin, tetracycline, diclofenac, ibuprofen, nimesulide, levonorgestrel, and 17α-ethynylestradiol exploiting micellar liquid chromatography with PDA detector and solid-phase extraction was proposed. The usage of toxic solvents was low; the chromatographic separation of the medicaments was performed using a C18 column and mobile phases A and B containing 15.0% (v/v) ethanol, 3.0% (m/v) sodium dodecyl sulfate (SDS), and 0.02 mol·L−1 phosphate at pHs 7.0 and 8.0, respectively. The method is simple, selective, and fast, and the analytes were separated in 23.0 min. For extraction, 1000 mL of sample containing 2.0% (v/v) ethanol and 0.002 mol·L−1 citric acid at pH 2.50 was loaded through a 1000 mg of C18 cartridge. The analytes were eluted using 3.0 mL of ethanol, which were evaporated and redissolved in 0.5 mL of mobile phase. Concentration factors better than 1200, except amoxicillin (224), were obtained. The analytical curves were linear (R2 better than 0.992); LOD and LOQ n=10 presented values in the range of 0.019–0.247 and 0.058–0.752 mg·L−1, respectively. Recoveries of 99% were obtained, and the results are in agreement with those obtained by the comparative methods.


2017 ◽  
Vol 7 (16) ◽  
pp. 31-37 ◽  
Author(s):  
Leonard Smith ◽  
Mitko Voutchkov

Background. Radon is a known carcinogen and contaminant in drinking water wells, but is not monitored in drinking water quality programs in Jamaica. Objective. The present study was conducted to obtain radon data in local drinking water and evaluate potential health risks. The data will contribute to determining the level of compliance to public health criteria for radon and to develop a monitoring program based on the identified risks. Methods. This study assesses the concentration of radon in 22 drinking water wells in the parish of St. Catherine, Jamaica. Samples were collected for radon, with 12 other measurements gathered including pH, conductivity, TDS, alkalinity, hardness, phosphates, nitrates, chloride, sulfates, turbidity, well depth and geological features. The data were analyzed for compliance to international limits and association with geological and other parameters. Results. The average radon level was 18 Bq/L ± 2 Bq/L and varied from a low of 11 Bq/L ± 1 Bq/L to a high of 41 Bq/L ± 1 Bq/L. There was a positive correlation between radon levels and both alkalinity and turbidity. No relationship of any significance, however, was identified with the other physicochemical parameters. All the study results fell within the European Union (EU) limit of 100 Bq/L, and well within the United States Environmental Protection Agency (USEPA) limit of 147 Bq/L. Most of the wells in this parish have radon levels exceeding the proposed USEPA limit of 11 Bq/L. The proposed limits are intended to support radon mitigation programs to manage radon in air. No limits are provided in the newest edition of the World Health Organization's (WHO) Guidelines for Safe Drinking Water Quality. Conclusions. Most wells in the study area met existing international limits. Almost all, however, did not meet the proposed USEPA limit for locations without radon mitigation programs. This indicates the need to establish national screening levels for radon, consistent with WHO and USEPA recommendations. Competing Interests. The authors declare no competing financial interests.


Molecules ◽  
2021 ◽  
Vol 26 (13) ◽  
pp. 3791
Author(s):  
Ewelina Patyra ◽  
Krzysztof Kwiatek

Rapid chromatographic procedure for quantification of five sulfonamides in medicated feeds are proposed. Satisfactory separation of sulfonamides from medicated feeds was achieved using a Zorbax Eclipse XDB C18 column (4.6 × 150 mm, 5 µm particle size) with a micellar mobile phase consisting of 0.05 M sodium dodecyl sulphate, 0.02 M phosphate buffer, and 6% propan-2-ol (pH 3). UV quantitation was set at 260 nm. The proposed procedure allows the determination of sulfaguanidine, sulfadiazine, sulfamerazine, sulfamethazine, and sulfamethoxazole in medicated feeds for pigs and poultry. Application of the proposed method to the analysis of five pharmaceuticals gave recoveries between 72.7% to 94.7% and coefficients of variations for repeatability and reproducibility between 2.9% to 9.8% respectively, in the range of 200 to 2000 mg/kg sulfonamides in feeds. Limit of detection and limit of quantification were 32.7–56.3 and 54.8–98.4 mg/kg, respectively, depending on the analyte. The proposed procedure for the quantification of sulfonamides is simple, rapid, sensitive, free from interferences and suitable for the routine control of feeds. In the world literature, we did not find the described method of quantitative determination of sulfonamides in medicated feeds with the use of micellar liquid chromatography.


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