scholarly journals Novel Chromatographic Separation and Carbon Solid-Phase Extraction of Acetanilide Herbicide Degradation Products

2002 ◽  
Vol 85 (6) ◽  
pp. 1331-1337 ◽  
Author(s):  
Jody A Shoemaker
Keyword(s):  
Drinking Water ◽  
Solid Phase Extraction ◽  
Chromatographic Separation ◽  
Solid Phase ◽  
Degradation Products ◽  
The United States ◽  
Negative Ion ◽  
Phase Extraction ◽  
Herbicide Degradation ◽  
Relative Standard

Abstract One acetamide and 5 acetanilide herbicides are currently registered for use in the United States. Over the past several years, ethanesulfonic acid (ESA) and oxanilic acid (OA) degradation products of these acetanilide/acetamide herbicides have been found in U.S. ground waters and surface waters. Alachlor ESA and other acetanilide degradation products are listed on the U.S. Environmental Protection Agency's (EPA) 1998 Drinking Water Contaminant Candidate List. Consequently, EPA is interested in obtaining national occurrence data for these contaminants in drinking water. EPA currently does not have a method for determining these acetanilide degradation products in drinking water; therefore, a research method is being developed using liquid chromatography/negative ion electrospray/mass spectrometry with solid-phase extraction (SPE). A novel chromatographic separation of the acetochlor/alachlor ESA and OA structural isomers was developed which uses an ammonium acetate–methanol gradient combined with heating the analytical column to 70°C. Twelve acetanilide degradates were extracted by SPE from 100 mL water samples using carbon cartridges with mean recoveries >90% and relative standard deviations ≤16%.

scholarly journals Development of EPA Method 535 for the Determination of Chloroacetanilide and Other Acetamide Herbicide Degradates in DrinkingWater by Solid-Phase Extraction and Liquid Chromatography/TandemMass Spectrometry

2006 ◽  
Vol 89 (1) ◽  
pp. 201-209 ◽  
Author(s):  
Jody A Shoemaker ◽  
Margarita V Bassett
Keyword(s):  
Drinking Water ◽  
Liquid Chromatography ◽  
Solid Phase Extraction ◽  
Environmental Protection Agency ◽  
Method Development ◽  
Solid Phase ◽  
Degradation Products ◽  
Internal Standard ◽  
Phase Extraction ◽  
Relative Standard

Abstract U.S. Environmental Protection Agency (EPA) Method 535 has been developed in order to provide a method for the analysis of Alachlor ESA and other acetanilide degradation products, which are listed on EPA's 1998 Drinking Water Contaminant Candidate List. Method 535 uses solid-phase extraction with a nonporous graphitized carbon sorbent to extract the ethane sulfonic acid (ESA) and oxanilic acid degradates of propachlor, flufenacet, dimethenamid, alachlor, acetochlor, and metolachlor from finished drinking water matrixes. Separation and quantitation of the target analytes are achieved with liquid chromatography/tandem mass spectrometry. Dimethachlor ESA and butachlor ESA were chosen during the method development as the surrogate and internal standard. Drinking water samples were dechlorinated with ammonium chloride without adversely affecting the analyte recoveries. Typical mean recoveries of 92116% in deionized water and 89116% in ground water were observed with relative standard deviations of <5%.

Optimizing Pretreatment Methods and Application for Analysis of Geosmin and 2-Methylisobomeol in Drinking Water

2014 ◽  
Vol 700 ◽  
pp. 525-529 ◽  
Author(s):  
Wu Chang Song ◽  
Xing Li ◽  
Shao Hua Sun ◽  
Yan Ling Yang ◽  
Rui Bao Jia
Keyword(s):  
Drinking Water ◽  
Standard Deviation ◽  
Solid Phase Extraction ◽  
Solid Phase ◽  
Liquid Extraction ◽  
Phase Extraction ◽  
Solid Phase Micro Extraction ◽  
Liquid Liquid Extraction ◽  
Taste And Odor ◽  
Relative Standard

The different pretreatment methods for analysis of geosmin and 2-methylisobomeol by GC-MS in drinking water were systemically studied and applied, such as liquid-liquid extraction, solid phase extraction, and solid phase micro-extraction. The results show that solid phase extraction is the better one, which C18 and carbinol were adopted as filling and washing solvents. The relative standard deviation of SPE-GC-MS for analysis geosmin and 2-Methylisoborneol were 1.5% and 1.7%, the recovery rate were in the range of 98.8%~102.0% and 99.5%~104.0%, respectively. 2-methylisobomeol was the major taste and odor of a micro-polluted reservoir in later autumn to earlier winter, which was secreted by Planktothrix and Oscillatoria.

Factorial Design Optimisation of Solid Phase Extraction for Preconcentration of Parabens in Wastewater Using Ultra-High Performance Liquid Chromatography Triple Quadrupole Mass Spectrometry

2020 ◽  
Vol 16 (4) ◽  
pp. 436-446
Author(s):  
Vallerie A. Muckoya ◽  
Philiswa N. Nomngongo ◽  
Jane C. Ngila
Keyword(s):  
Solid Phase Extraction ◽  
Formic Acid ◽  
Factorial Design ◽  
Solid Phase ◽  
Treatment Plant ◽  
Phase Extraction ◽  
Limit Of Quantification ◽  
Analytical Technique ◽  
Relative Standard ◽  
Simulated Wastewater

Background: Parabens are synthetic esters used extensively as preservatives and/or bactericides in personal care personal products. Objective: Development and validation of a novel robust chemometric assisted analytical technique with superior analytical performances for the determination of ethylparaben, methylparaben and propylparaben, using simulated wastewater matrix. Methods: An automated Solid Phase Extraction (SPE) method coupled with liquid chromatographymass spectrometry was applied in this study. A gradient elution programme comprising of 0.1% formic acid in deionised water (A) and 0.1% formic acid in Methanol (B) was employed on a 100 x 2.1 mm, 3.0 μm a particle size biphenyl column. Two-level (2k) full factorial design coupled with response surface methodology was used for optimisation and investigation of SPE experimental variables that had the most significant outcome of the analytical response. Results: According to the analysis of variance (ANOVA), sample pH and eluent volume were statistically the most significant parameters. The method developed was validated for accuracy, precision, Limits of Detection (LOD) and Limit of Quantification (LOQ) and linearity. The LOD and LOQ established under those optimised conditions varied between 0.04-0.12 μgL−1 and 0.14-0.40 μgL−1 respectively. The use of matrix-matched external calibration provided extraction recoveries between 78-128% with relative standard deviations at 2-11% for two spike levels (10 and 100 μgL-1) in three different water matrices (simulated wastewater, influent and effluent water). Conclusion: The newly developed method was applied successfully to the analyses of parabens in wastewater samples at different sampling points of a wastewater treatment plant, revealing concentrations of up to 3 μgL−1.

Green Dispersive Micro Solid-Phase Extraction using Multiwalled Carbon Nanotubes for Preconcentration and Determination of Cadmium and Lead in Food, Water, and Tobacco Samples

2020 ◽  
Vol 16 (4) ◽  
pp. 381-392
Author(s):  
Ayman A. Gouda ◽  
Ali H. Amin ◽  
Ibrahim S. Ali ◽  
Zakia Al Malah
Keyword(s):  
Carbon Nanotubes ◽  
Solid Phase Extraction ◽  
Multiwalled Carbon Nanotubes ◽  
Solid Phase ◽  
Certified Reference Materials ◽  
Phase Extraction ◽  
Multiwalled Carbon ◽  
Flame Atomic Absorption ◽  
Relative Standard ◽  
Separation And Preconcentration

Background: Cadmium (Cd2+) and lead (Pb2+) have acute and chronic effects on humans and other living organisms. In the present work, new, green and accurate dispersive micro solid-phase extraction (DμSPE) method for the separation and preconcentration of trace amounts of cadmium (Cd2+) and lead (Pb2+) ions in various food, water and tobacco samples collected from Saudi Arabia prior to its Flame Atomic Absorption Spectrometric (FAAS) determinations was developed. Methods: The proposed method was based on a combination of oxidized multiwalled carbon nanotubes (O-MWCNTs) with a new chelating agent 5-benzyl-4-[4-methoxybenzylideneamino)-4H- 1,2,4-triazole-3-thiol (BMBATT) to enrich and separate trace levels of Cd2+ and Pb2+. The effect of separation parameters was investigated. The validation of the proposed preconcentration procedure was performed using certified reference materials. Results: Analyte recovery values ranged from 95-102%, indicating that the method is highly accurate. Furthermore, precision was demonstrated by the relative standard deviation (RSD < 3.0%). The limits of detection were 0.08 and 0.1 μg L−1 for Cd2+ and Pb2+ ions, respectively. The preconcentration factor was 200. Conclusion: The proposed method was used for the estimation of Cd2+ and Pb2+ ion content in various real samples, and satisfactory results were obtained. The proposed method has high adsorption capacity, rapid adsorption equilibrium, extremely low LODs, high preconcentration factors and shortens the time of sample preparation in comparison to classical SPE.

Development of a solid-phase extraction – spectrofluorimetric method for trace glutathione determination

2011 ◽  
Vol 89 (4) ◽  
pp. 517-523 ◽  
Author(s):  
Ke-Jing Huang ◽  
Cong-Hui Han ◽  
Ying-Ying Wu ◽  
Chao-Qun Han ◽  
De-Jun Niu ◽  
...  
Keyword(s):  
Solid Phase Extraction ◽  
Limit Of Detection ◽  
Solid Phase ◽  
Signal To Noise Ratio ◽  
Calibration Graph ◽  
Extraction Column ◽  
Phase Extraction ◽  
Selective Reaction ◽  
Spectrofluorimetric Method ◽  
Relative Standard

A simple and efficient solid-phase extraction – spectrofluorimetric method has been developed to determine glutathione (GSH). Fluorescent probe N-(4,4-difluoro-5,7-dimethyl-4-bora-3a,4a-diaza-s-indacene-3-yl)methyl)iodoacetamide (BODIPY Fl-C1-IA) was used as the derivatization reagent. The procedure was based on a BODIPY Fl-C1-IA selective reaction with GSH to form the highly fluorescent product BODIPY Fl-C1-IA–GSH, using a solid-phase extraction column and spectrofluorimetric determination. The variables affecting analytical performance were studied and optimized. The calibration graph using the preconcentration system for GSH was linear over the range of 1–200 nmol/L with a limit of detection of 0.05 nmol/L (signal-to-noise ratio = 3). The relative standard deviation for six replicate determinations of GSH at the 100 nmol/L concentration level was 3.9%. The method was applied to water samples and average recoveries between 87.5% and 111.5% were obtained for spiked samples.

scholarly journals Solid-Phase Extraction and Reverse-Phase HPLC: Application to Study the Urinary Excretion Pattern of Benzophenone-3 and its Metabolite 2,4-Dihydroxybenzophenone in Human Urine

2008 ◽  
Vol 3 ◽  
pp. ACI.S396 ◽  
Author(s):  
Helena Gonzalez ◽  
Carl-Eric Jacobson ◽  
Ann-Marie Wennberg ◽  
Olle Larkö ◽  
Anne Farbrot
Keyword(s):  
Solid Phase Extraction ◽  
Urinary Excretion ◽  
Human Urine ◽  
Solid Phase ◽  
Whole Body ◽  
Phase Extraction ◽  
Reverse Phase Hplc ◽  
Reverse Phase ◽  
Excretion Pattern ◽  
Relative Standard

Background Benzophenone-3 (BZ-3) is a common ultraviolet (UV) absorbing compound in sunscreens. It is the most bioavailable species of all UV-absorbing compounds after topical application and can be found in plasma and urine. Objectives The aim of this study was to develop a reverse-phase high performance liquid chromatography (HPLC) method for determining the amounts BZ-3 and its metabolite 2,4-dihydroxybenzophenone (DHB) in human urine. The method had to be suitable for handling a large number of samples. It also had to be rapid and simple, but still sensitive, accurate and reproducible. The assay was applied to study the urinary excretion pattern after repeated whole-body applications of a commercial sunscreen, containing 4% BZ-3, to 25 healthy volunteers. Methods Each sample was analyzed with regard to both conjugated/non-conjugated BZ-3 and conjugated/non-conjugated DHB, since both BZ-3 and DHB are extensively conjugated in the body. Solid-phase extraction (SPE) with C8 columns was followed by reverse-phase HPLC. For separation a Genesis C18 column was used with an acethonitrile-water mobile phase and the UV-detector was set at 287 nm. Results The assay was linear r 2 > 0.99, with detection limits for BZ-3 and DHB of 0.01 µmol L-1 and 0.16 µmol L-1 respectively. Relative standard deviation (RSD) was less than 10% for BZ-3 and less than 13% for DHB. The excretion pattern varied among the human volunteers; we discerned different patterns among the individuals. Conclusions The reverse-phase HPLC assay and extraction procedures developed are suitable for use when a large number of samples need to be analyzed and the method fulfilled our objectives. The differences in excretion pattern may be due to differences in enzyme activity but further studies, especially about genetic polymorphism, need to be performed to verify this finding.

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