scholarly journals Bisphenol A: Quantification in Complex Matrices and Removal by Anaerobic Sludges

Pollutants ◽  
2021 ◽  
Vol 1 (4) ◽  
pp. 194-206
Author(s):  
Justus Hardegen ◽  
Patrick Braeutigam ◽  
Christian Abendroth ◽  
Thomas Wichard
Keyword(s):  
Bisphenol A ◽  
Biogas Production ◽  
Internal Standard ◽  
Dry Weight ◽  
Gas Chromatography Mass Spectrometry ◽  
Anaerobic Conditions ◽  
Complex Matrices ◽  
Limit Of Quantification ◽  
Biogas Plants ◽  
User Friendly

The endocrine disruptor bisphenol A (BPA) is one of the most commonly found micropollutants in the environment. However, the biodegradation of BPA under anaerobic (methanogenic) conditions is still an understudied process in wastewater treatment systems. The current study thus addresses the need for a simple and user-friendly analytical method for the rapid and accurate quantification of BPA in complex matrices such as digested and co-digester sludges. We established a microwave-assisted extraction method, followed by derivatization and gas chromatography–mass spectrometry to quantify BPA by comparing it with a deuterated internal standard. The BPA removal capabilities of three digester sludges and three co-digester sludges were examined under mesophilic methanogenic conditions in biogas plants. The endogenous BPA concentration (dry weight) ranged from 1596 to 10,973 µg kg−1 in digested sewage sludges, and from below the limit of quantification to 9069 µg kg−1 in co-digester sludges. When BPA was added to the sludges, the removal capabilities ranged from not significant to 50% after 21 days of incubation. Biogas production was unaffected by the addition of BPA (228 µg kg−1) to the aqueous sludge. The study demonstrated that BPA could be removed under anaerobic conditions in accustomed inoculates. The findings have far-reaching implications for understanding BPA persistence and detoxification under anaerobic conditions.

scholarly journals Development and Validation of a GC-MS Method for the Detection and Quantification of Clotiapine in Blood and Urine Specimens and Application to a Postmortem Case

2015 ◽  
Vol 2015 ◽  
pp. 1-5 ◽  
Author(s):  
Giulio Mannocchi ◽  
Flaminia Pantano ◽  
Roberta Tittarelli ◽  
Miriam Catanese ◽  
Federica Umani Ronchi ◽  
...  
Keyword(s):  
Limit Of Detection ◽  
Internal Standard ◽  
Urine Samples ◽  
Gas Chromatography Mass Spectrometry ◽  
Published Data ◽  
Limit Of Quantification ◽  
Blood And Urine Samples ◽  
Development And Validation ◽  
Urine Specimens ◽  
Detection And Quantification

Introduction. Clotiapine is an atypical antipsychotic of the dibenzothiazepine class introduced in a few European countries since 1970, efficient in treatment-resistant schizophrenic patients. There is little published data on the therapeutic and toxic concentrations of this drug.Aims. The aim of the present study is the development and validation of a method that allows the detection and quantification of clotiapine in blood and urine specimens by gas chromatography-mass spectrometry (GC-MS).Methods. Validation was performed working on spiked postmortem blood and urine samples. Samples were extracted with liquid-liquid extraction (LLE) technique at pH 8.5 with n-hexane/dichloromethane (85/15 v/v) and analysis was followed by GC-MS. Methadone-d9 was used as internal standard.Results. The limit of detection (LOD) was 1.2 and 1.3 ng/mL for urine and blood, respectively, while the lower limit of quantification (LLOQ) was 3.9 and 4.3 ng/mL, respectively. Linearity, precision, selectivity, accuracy, and recovery were also determined. The method was applied to a postmortem case. The blood and urine clotiapine concentrations were 1.32 and 0.49 μg/mL, respectively.Conclusions. A reliable GC-MS method for the detection and quantification of clotiapine in blood and urine samples has been developed and fully validated and then applied to a postmortem case.

Fast and Sensitive LC-MS Detection of Bisphenol A and Butylhydroxyanisole in WWTP Sewage Sludge

2019 ◽  
Vol 70 (6) ◽  
pp. 2123-2127 ◽  
Author(s):  
Florentina Laura Chiriac ◽  
Iuliana Paun ◽  
Florinela Pirvu ◽  
Vasile Iancu ◽  
Toma Galaon
Keyword(s):  
Sewage Sludge ◽  
Bisphenol A ◽  
Internal Standard ◽  
High Sensitivity ◽  
Dry Weight ◽  
Detector Response ◽  
Assisted Extraction ◽  
Ultrasonic Assisted ◽  
Sensitivity And Selectivity ◽  
Chromatographic Parameters

In this study, a new LC-MS/MS method was developed and optimized in order to detect two omnipresent additives, Bisphenol A (BPA) and Butylhydroxyanisole (BHA), in WWTP sewage sludge. Both analytes are synthetic phenolic compounds known for their endocrine disruptive and toxic properties. BPA and BHA were isolated from sludge samples using ultrasonic assisted liquid-solid extraction followed by silicagel clean-up to remove interferences, and evaporation to dryness and extract re-dissolution with 1 mL methanol prior to LC-MS analysis. All LC-MS parameters were optimized in order to obtain high sensitivity and selectivity. MS detector response was linear in the range 1 � 200 �g/L with correlation coefficient R2 ] 0.999 for both analytes. Intra-day and inter-day precision expressed as RSD values were 4.7% and 10.3% for BPA, whereas for BHA 7.8% and 13.8% RSD values were obtained. Recovery values after ultrasonic assisted extraction were 85.5% for BPA and 79.3% BHA with internal standard correction. Overall method LOQs were established at 1.97 ng/g (BPA) and 1.86 ng/g (BHA) on dry weight. Optimized chromatographic parameters allowed separation and detection of the two additives in less than 10 minutes. Both BPA and BHA were detected in all tested sludge samples with higher levels for BPA (34.6 - 132.6 ng/g), whereas BHA was found at lower levels in the range 3.16 - 5.64 ng/g.

scholarly journals Development and validation of a GC–MS method for the simultaneous determination of acetochlor, fluorochloridone, and pendimethalin in a herbicide emulsifiable concentrate formulation

2020 ◽  
Vol 32 (4) ◽  
pp. 238-241 ◽  
Author(s):  
Dandan Wang ◽  
Shengde Wu
Keyword(s):  
Internal Standard ◽  
Ternary Mixtures ◽  
Gas Chromatography Mass Spectrometry ◽  
Selected Ion Monitoring ◽  
Limit Of Quantification ◽  
Emulsifiable Concentrate ◽  
Relative Standard ◽  
Replicate Measurements ◽  
Development And Validation

This paper describes a rapid method to simultaneously determine acetochlor, fluorochloridone and pendimethalin present in a herbicide emulsifiable concentrate (EC) formulation using gas chromatography–mass spectrometry (GC–MS). Selected ion monitoring mode was performed to increase the sensitivity, with dibutyl phthalate as an internal standard. The method was validated with respect to linearity, accuracy, precision, and stability. Chromatographic separation was carried out on a TG-5 MS column (30 m × 0.25 mm × 0.25 μm) with helium as the carrier gas at a flow rate of 1.0 mL/min. Calibration curves were linear over 2.0–20.0 μg/mL for each analyte, and the limit of quantification was below 20 ng/mL. Good performance in terms of recovery ranging from 94.5% to 102.5% at 3 concentration levels proved excellent accuracy. The intra- and inter-day relative standard deviations for 6 replicate measurements were always less than 5%. The developed method is simple and efficient for the routine determination of the ternary mixtures in a compound herbicide EC formulation product.

scholarly journals Routine analysis of plasma busulfan by gas chromatography–mass fragmentography

1998 ◽  
Vol 44 (12) ◽  
pp. 2506-2510 ◽  
Author(s):  
Wai-Kai Lai ◽  
Chi-Pui Pang ◽  
Lap-Kay Law ◽  
Raymond Wong ◽  
Chi-Kong Li ◽  
...  
Keyword(s):  
Gas Chromatography ◽  
Internal Standard ◽  
Fused Silica ◽  
Routine Analysis ◽  
Gas Chromatography Mass Spectrometry ◽  
High Dose ◽  
Mass Fragmentography ◽  
Limit Of Quantification ◽  
Time Curve ◽  
Fused Silica Capillary

Abstract Busulfan (BU) is a widely used alkylating agent for antineoplastic therapy and marrow ablation in preparation for bone marrow transplantation (BMT). High-dose BU often leads to successful preparation and low relapse but is associated with veno-occlusive disease of liver. We established a protocol to determine postdosage plasma BU concentrations by gas chromatography–mass fragmentography in an attempt to relate clinical outcome to plasma BU concentrations. We used nonisotopic pusulfan as the internal standard. After extraction into ethyl acetate, BU and pusulfan were iodinated into 1,4-diiodobutane and 1,5-diiodopentane, respectively. Gas chromatography–mass spectrometry (GC–MS) analysis was carried out on an Hewlett–Packard (HP) 5890II gas chromatograph with a 30-m 100% methyl silicon narrow bore, fused-silica capillary column interfaced with an HP 5970A mass spectrometer. Helium was the carrier gas. The sample molecules were identified by total ion monitoring and quantified by selective ion monitoring of m/z 183 and 197. The calibration curve was linear to 4 mg/L. The limit of quantification was 0.04 mg/L, and the analytical recovery was ∼97%. The within-day and between-day imprecision (CV) was <6% and 9%, respectively. In a preliminary study of 12 children, the BU areas under the BU-time curve were 616–949 μmol · min/L after the first dose and 793-1143 μmol · min/L after the fifth dose. We conclude that the GC–MS procedure is suitable for routine analysis of plasma BU.

scholarly journals Simultaneous determination of C4-C9 alkylphenols and bisphenol A in environmental water at the Yellow River Estuary Area in China by gas chromatography-mass spectrometry

2021 ◽  
Author(s):  
hailliang yin ◽  
Tongna ZHOU ◽  
ziqi guo ◽  
xinliang liu ◽  
jian ZHAO
Keyword(s):  
Bisphenol A ◽  
Yellow River ◽  
River Estuary ◽  
Internal Standard ◽  
Environmental Water ◽  
Gas Chromatography Mass Spectrometry ◽  
The Yellow River ◽  
Internal Standard Method ◽  
Relative Standard

Abstract A liquid-liquid extraction combined with derivatization and gas chromatography-mass spectrometry (GC-MS) method was developed for the rapid determination of C4-C9 alkylphenols (4-tert-butylphenol, 4-n-butylphenol, 4-n-pentylphenol, 4-n-hexylphenol, 4-n-heptylphenol, 4-n-octylphenol, 4-tert-octylphenol, 4-n-nonylphenol and 4-nonylphenol) and bisphenol A in the environmental water. The extraction solvent, extraction time, solvent volume, acidity, salt content and the distillation degree were optimized. After drying and dehydration, the extract was derivatized, detected by GC-MS and quantified by internal standard method. After the dehydration, the extract was derivatized with BSTFA, detected by GC-MS and quantified by internal standard method. The results showed that the relative standard deviations of the relative response factors of the target compounds were less than 20%, the method detection limits were 0.002 µg/Lཞ0.006 µg/L, the relative standard deviations of the three spiked levels were 0.67%ཞ13.7%, and the average recoveries of the actual water samples were 68.0%ཞ122%. The method precision and accuracy were good. The method is simple, rapid, accurate, stable and reliable, which is suitable for the detection of target in water. The contents of C4-C9 alkylphenols and bisphenol A in groundwater, surface water, sewage, waste water and sea water samples in Dongying City located at the Yellow River Estuary were determined by this method. The results showed that the contents of 4-nonylphenol and bisphenol A in these samples were lower than the home and abroad requirements.

Characterization of frozen hydrated biological specimens by low-loss EELS

1992 ◽  
Vol 50 (2) ◽  
pp. 1572-1573
Author(s):  
Songquan Sun ◽  
Richard D. Leapman
Keyword(s):  
Water Content ◽  
Direct Method ◽  
Internal Standard ◽  
Dry Weight ◽  
Dark Field ◽  
Protein Solutions ◽  
Subcellular Compartment ◽  
Differential Shrinkage ◽  
Electron Energy Loss

Analyses of ultrathin cryosections are generally performed after freeze-drying because the presence of water renders the specimens highly susceptible to radiation damage. The water content of a subcellular compartment is an important quantity that must be known, for example, to convert the dry weight concentrations of ions to the physiologically more relevant molar concentrations. Water content can be determined indirectly from dark-field mass measurements provided that there is no differential shrinkage between compartments and that there exists a suitable internal standard. The potential advantage of a more direct method for measuring water has led us to explore the use of electron energy loss spectroscopy (EELS) for characterizing biological specimens in their frozen hydrated state.We have obtained preliminary EELS measurements from pure amorphous ice and from cryosectioned frozen protein solutions. The specimens were cryotransfered into a VG-HB501 field-emission STEM equipped with a 666 Gatan parallel-detection spectrometer and analyzed at approximately −160 C.

STEM measurement of subcellular water distributions

1993 ◽  
Vol 51 ◽  
pp. 568-569
Author(s):  
R.D. Leapman ◽  
S.Q. Sun ◽  
S-L. Shi ◽  
R.A. Buchanan ◽  
S.B. Andrews
Keyword(s):  
Water Content ◽  
Internal Standard ◽  
Dry Weight ◽  
Dry Mass ◽  
Scanning Transmission Electron Microscope ◽  
Dark Field ◽  
Bulk Water ◽  
Inelastic Electron ◽  
Scanning Transmission ◽  
Annular Dark Field

Recent advances in rapid-freezing and cryosectioning techniques coupled with use of the quantitative signals available in the scanning transmission electron microscope (STEM) can provide us with new methods for determining the water distributions of subcellular compartments. The water content is an important physiological quantity that reflects how fluid and electrolytes are regulated in the cell; it is also required to convert dry weight concentrations of ions obtained from x-ray microanalysis into the more relevant molar ionic concentrations. Here we compare the information about water concentrations from both elastic (annular dark-field) and inelastic (electron energy loss) scattering measurements.In order to utilize the elastic signal it is first necessary to increase contrast by removing the water from the cryosection. After dehydration the tissue can be digitally imaged under low-dose conditions, in the same way that STEM mass mapping of macromolecules is performed. The resulting pixel intensities are then converted into dry mass fractions by using an internal standard, e.g., the mean intensity of the whole image may be taken as representative of the bulk water content of the tissue.

Development and Validation of a New Method for the Determination of Anti-hepatitis C Agent Simeprevir in Human Plasma using HPLC with Fluorescence Detection

2020 ◽  
Vol 16 (4) ◽  
pp. 428-435
Author(s):  
Ahmed F.A. Youssef ◽  
Yousry M. Issa ◽  
Kareem M. Nabil
Keyword(s):  
Hepatitis C ◽  
Human Plasma ◽  
Fluorescence Detection ◽  
Internal Standard ◽  
Protein Precipitation ◽  
Assay Method ◽  
Fluorescence Detector ◽  
Limit Of Quantification ◽  
Relative Standard

Background: Simeprevir is one of the recently discovered drugs for treating hepatitis C which is one of the major diseases across the globe. Objective: The present study involves the development of a new and unique High-Performance Liquid Chromatography (HPLC) method using fluorescence detection for the determination of simeprevir (SIM) in human plasma. Methods: Two methods of extractions were tested, protein precipitation using acetonitrile and liquidliquid extraction. A 25 mM dipotassium hydrogen orthophosphate (pH 7.0)/ACN (50/50; v/v), was used as mobile phase and C18 reversed phase column as the stationary phase. The chromatographic conditions were optimized and the concentration of simeprevir was determined by using the fluorescence detector. Cyclobenzaprine was used as an internal standard. Results: Recovery of the assay method based on protein precipitation was up to 100%. Intra-day and inter-day accuracies range from 92.30 to 107.80%, with Relative Standard Deviation (RSD) range 1.65-8.02%. The present method was successfully applied to a pharmacokinetic study where SIM was administered as a single dose of 150 mg SIM/capsule (Olysio®) to healthy individuals. Conclusion: This method exhibits high sensitivity with a low limit of quantification 10 ng mL-1, good selectivity using fluorescence detection, wide linear application range 10-3000 ng mL-1, good recovery and highly precise and validation results. The developed method can be applied in routine analysis for real samples.

scholarly journals UV Stimulated Manganese Dioxide for the Persulfate Catalytic Degradation of Bisphenol A

Catalysts ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 502
Author(s):  
Guihua Dong ◽  
Bing Chen ◽  
Bo Liu ◽  
Stanislav R. Stoyanov ◽  
Yiqi Cao ◽  
...  
Keyword(s):  
Bisphenol A ◽  
Reaction Mechanisms ◽  
Reduction Rate ◽  
Catalytic Degradation ◽  
Gas Chromatography Mass Spectrometry ◽  
Degradation Pathways ◽  
Industrial Chemicals ◽  
Oh Groups ◽  
Long Term Adverse Effects

One of the most commonly produced industrial chemicals worldwide, bisphenol A (BPA), is used as a precursor in plastics, resins, paints, and many other materials. It has been proved that BPA can cause long-term adverse effects on ecosystems and human health due to its toxicity as an endocrine disruptor. In this study, we developed an integrated MnO2/UV/persulfate (PS) process for use in BPA photocatalytic degradation from water and examined the reaction mechanisms, degradation pathways, and toxicity reduction. Comparative tests using MnO2, PS, UV, UV/MnO2, MnO2/PS, and UV/PS processes were conducted under the same conditions to investigate the mechanism of BPA catalytic degradation by the proposed MnO2/UV/PS process. The best performance was observed in the MnO2/UV/PS process in which BPA was completely removed in 30 min with a reduction rate of over 90% for total organic carbon after 2 h. This process also showed a stable removal efficiency with a large variation of pH levels (3.6 to 10.0). Kinetic analysis suggested that 1O2 and SO4•− played more critical roles than •OH for BPA degradation. Infrared spectra showed that UV irradiation could stimulate the generation of –OH groups on the MnO2 photocatalyst surface, facilitating the PS catalytic degradation of BPA in this process. The degradation pathways were further proposed in five steps, and thirteen intermediates were identified by gas chromatography-mass spectrometry. The acute toxicity was analyzed during the treatment, showing a slight increase (by 3.3%) in the first 30 min and then a decrease by four-fold over 2 h. These findings help elucidate the mechanism and pathways of BPA degradation and provide an effective PS catalytic strategy.

scholarly journals Analysis of Pembrolizumab in Human Plasma by LC-MS/HRMS. Method Validation and Comparison with Elisa

Biomedicines ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 621
Author(s):  
Aurélien Millet ◽  
Nihel Khoudour ◽  
Jérôme Guitton ◽  
Dorothée Lebert ◽  
François Goldwasser ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Human Plasma ◽  
High Resolution Mass Spectrometry ◽  
Internal Standard ◽  
Therapeutic Drug ◽  
Limit Of Quantification ◽  
Immunoglobulin G4 ◽  
Positive Mode ◽  
Surrogate Peptide ◽  
First Time

Pembrolizumab is a humanized immunoglobulin G4-kappa anti-PD1 antibody used in the treatment of different solid tumors or haematological malignancies. A liquid chromatography coupled with a high resolution mass spectrometry (orbitrap technology) method was fully developed, optimized, and validated for quantitative analysis of pembrolizumab in human plasma. A mass spectrometry assay was used for the first time a full-length stable isotope-labelled pembrolizumab-like (Arginine 13C6-15N4 and Lysine 13C6-15N2) as an internal standard; the sample preparation was based on albumin depletion and trypsin digestion and, finally, one surrogate peptide was quantified in positive mode. The assay showed good linearity over the range of 1–100 μg/mL, a limit of quantification at 1 μg/mL, excellent accuracy from 4.4% to 5.1%, and also a between-day precision below 20% at the limit of quantification. In parallel, an in-house ELISA was developed with a linearity range from 2.5 to 50 µg/mL. Then, results were obtained from 70 plasma samples of cancer patients that were treated with pembrolizumab and quantified with both methods were compared using the Passing-Bablok regression analysis and Bland-Altman plotting. The LC-MS/HRMS method is easy to implement in the laboratory for use in the context of PK/PD studies, clinical trials, or therapeutic drug monitoring.

Sign in / Sign up

Export Citation Format

Share Document