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1.
Biomed Chromatogr ; 37(10): e5705, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37525473

RESUMO

The present study on "acephate persistence on green pea" was conducted in SKUAST-Kashmir. The study aimed to determine the persistence, dissipation kinetics and waiting period of acephate on green pea. Acephate was sprayed at 75% soluble powder (SP) at 560 g a.i.ha-1 at the fruiting stage followed by another application at a 10 day interval. A rapid and accurate method (quick, easy, cheap, effective, rugged and safe, QuEChERS) was used for extraction and the residue was determined by gas chromatography-electron capture detection on a CPSIL-8CB capillary column (0.25um film thickness, 0.25 mm i.d, 30 m length). At the fortification levels of 0.05, 0.1 and 0.5 mg kg-1 , the percentage recovery of acephate on green pea was found in the range of 71-107%. The initial deposit of green pea was estimated to be 0.37 mg kg-1 . At the indicated dose, the residue of acephate on green pea dissipated below the limit of quantification of 0.05 mg kg-1 after 10 days. Acephate degradation was quick in green pea, with a half-life of 4.07 days. For safe eating of green peas, a 10 day waiting period is recommended. The gas chromatography-electron capture detection technique was validated by following the SANTE standards.


Assuntos
Resíduos de Praguicidas , Pisum sativum , Cinética , Pisum sativum/química , Resíduos de Praguicidas/análise , Elétrons , Cromatografia Gasosa/métodos , Medição de Risco
2.
J Pharm Biomed Anal ; 229: 115349, 2023 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-36989666

RESUMO

Static headspace capillary gas chromatography (HSGC) has been employed to monitor the level of residual solvents in the pharmaceutical materials. Most of the HSGC methods, however, consume significant amounts of diluents and require considerable amount of sample preparation time. Accordingly, a HSGC method featured with fast turnaround time, and minimal amount of solvent use has been developed for the quantitative analysis of 27 residual solvents frequently used in the development and manufacturing processes of pharmaceutical industry. This HSGC-FID method employs a commercially available fused silica capillary column, a split injection (40:1), and a programmed temperature ramp. It was qualified for specificity, accuracy, repeatability/precision, linearity, LOQ, solution stability, and robustness using two representative sample matrices. The standards, samples and spiked samples were demonstrated to be stable for at least 10 days at room temperature in sealed headspace vials with a recovery of ≥ 93%. The method was also shown to be robust, and its performance was not affected by small changes of carrier gas flow rate, initial oven temperature or the headspace oven temperature. In this new approach, the analytical sample was prepared by dissolving the sample into 1 mL of the diluent and the standard solution was prepared by diluting 1 mL of the custom-made stock into 9 mL of the diluent whereas the traditional approach requires liters of the diluent, making the new approach environmentally friendly, sustainable, economical, agile, error-proofing and thus appropriate for a variety of pharmaceutical applications.


Assuntos
Indústria Farmacêutica , Cromatografia Gasosa/métodos , Solventes/química , Temperatura , Indicadores e Reagentes , Preparações Farmacêuticas
3.
Environ Sci Pollut Res Int ; 30(11): 28916-28924, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36401015

RESUMO

This research surveyed the concentrations of five organophosphorus pesticides (OPs) in vegetables with the purpose of assessing the potential integrated health risks of residents. From 2018 to 2020, 870 samples of eight kinds of vegetables from Zhejiang Province were collected. Gas chromatography coupled with a flame photometric detector (GC-FPD) analyzed the five OPs. OPs were most frequently detected in celery (18.9% of samples), cowpeas (18.3% of samples), and leeks (16.9% of samples) compared to other vegetables. Among the 11 cities in Zhejiang, the cities with high detection rates of OPs were Ningbo and Hangzhou. The integrated concentrations of OPs in different cities ranged from 71.9 to 376 µg/kg. The cumulative risk assessment revealed that the estimated daily intake (EDI) of leek in Wenzhou was the highest, which was 0.0077 (mg/kg bw) and 0.0059 (mg/kg bw) in adults and children respectively. The health risks of residents who consume these vegetables were within a safe range. The data provided demonstrate the distribution and potential health hazards of OPs in commonly consumed vegetables.


Assuntos
Resíduos de Praguicidas , Praguicidas , Adulto , Criança , Humanos , Praguicidas/análise , Verduras/química , Compostos Organofosforados/análise , Cromatografia Gasosa/métodos , Cebolas , China , Resíduos de Praguicidas/análise , Contaminação de Alimentos/análise
4.
Ann Pharm Fr ; 81(1): 64-73, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-35803334

RESUMO

OBJECTIVE: A simple and robust head space/gas chromatography with flame ionisation sensor (HS/GC/FIS) approach for the trace evaluation of carcinogenic impurity, methyl chloride, in trimetazidine dihydrochloride (TRD) drug ingredient and its formulation is described. METHOD: This HS/GC/FIS approach was based on separation and analysis of CH3Cl content on DB-624 [75.0m - length, 0.53mm - internal diameter, 3.0µm - film thickness] column using nitrogen as carrier gas flowing through the column at 3mL/min stream rate. Detection of eluted CH3Cl was accomplished with flame ionization sensor at a set temperature of 260̊C. RESULTS: The optimised HS/GC/FIS methodological approach was thoroughly validated, demonstrating that it was linear with range of 5.0ppm to 1508.4ppm, sensitive with detection limit of 1.65ppm and quantification limit of 5.01ppm, reproducible with RSD values of 2.10-2.35%, accurate with recoveries of 81.9-99.0%, robust with percent variation of 7.5-12.22% with respect to changes in oven temperature, injector temperature, detector temperature and practical for regular TRD quality control. CONCLUSION: The findings revealed that with this optimised HS/GC/FIS methodological approach, the trace amounts of carcinogenic impurity (methyl chloride) in TRD drug ingredient and formulation could be successfully measured.


Assuntos
Cloreto de Metila , Trimetazidina , Trimetazidina/análise , Cloreto de Metila/análise , Carcinógenos/análise , Cromatografia Gasosa/métodos , Temperatura , Ionização de Chama
5.
Artigo em Inglês | MEDLINE | ID: mdl-35970072

RESUMO

The performance of different enzymes towards the bioprocessing of aroma-related compounds was investigated and a strategy based on GC-FID analysis was developed to facilitate assessment of the stages of characterisation, screening and optimisation, including chiral ratio determination. Characterisation included activity assays (UV-Vis and GC-FID), protein quantification (NanoDrop spectrophotometry) and molar mass estimation (SDS-PAGE electrophoresis). Screening experiments assessed different enzymes, substrates, solvents, acyl donors or mediators. Aroma-related substrates comprised terpene and phenolic compounds. The enzymes tested included the lipases CALA (Sigma-Aldrich), NZ-435, LZ-TLIM, NC-ADL, LZ-CALBL and the laccases NZ-51003 and DL-IIS (all from Novozymes). Among those, NZ-435 and NZ-51003 had the highest activities in the characterisation stage and, along with CALA, achieved conversions above 70% for citronellol (lipases) or 50% for eugenol (laccases) at the screening stage. The lipases had preference for the primary alcohol and laccases for phenolic compounds, among the tested substrates. The transesterification reaction between the lipase CALA and the standards mixture (citronellol, menthol, linalool) was used to demonstrate the optimisation stage, where the best levels of temperature, enzyme and acyl donor concentrations were investigated. Optimum conditions were found to be 37-40 °C, 3-4 mg/mL of enzyme and 58-60% (v/v) vinyl acetate. Additional confirmation experiments using the same terpene standards mixture and citronella oil sample, gave a conversion of > 95% for citronellol after 1 h (for both, standards mixture and sample), and 20% or 74% for menthol after 1 h or 24 h, respectively. None of the tested enzymes demonstrated significant enantioselectivity under the tested conditions. The GC-FID approach demonstrated here was suitable to determine the reaction profiles and chiral ratio variations for biocatalysed reactions with aroma compounds in low complexity samples. Advanced separations will be applied to more complex samples in the future.


Assuntos
Mentol , Odorantes , Monoterpenos Acíclicos , Cromatografia Gasosa/métodos , Lipase , Odorantes/análise , Terpenos/análise
6.
Molecules ; 27(13)2022 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-35807216

RESUMO

Rice cultivation is one of the most significant human-created sources of methane gas. How to accurately measure the methane concentration produced by rice cultivation has become a major problem. The price of the automatic gas sampler used as a national standard for methane detection (HJ 38-2017) is higher than that of gas chromatography, which greatly increases the difficulty of methane detection in the laboratory. This study established a novel methane detection method based on manual injection and split pattern by changing the parameters of the national standard method without adding any additional automatic gas samplers. The standard curve and correlation coefficient obtained from the parallel determination of methane standard gas were y = 2.4192x + 0.1294 and 0.9998, respectively. Relative standard deviation (RSD, <2.82%), recycle rate (99.67−102.02%), limit of detection (LOD, 0.0567 ppm) and limit of quantification (LOQ, 0.189 ppm) of this manual injection method are satisfying, demonstrating that a gas chromatography-flame ionization detector (GC-FID), based on manual injection at a split ratio (SR) of 5:1, could be an effective and accurate method for methane detection. Methane gases produced by three kinds of low-methane rice treated with oxantel pamoate acid, fumaric acid and alcohol, were also collected and detected using the proposed manual injection approach Good peak shapes were obtained, indicating that this approach could also be used for quantification of methane concentration.


Assuntos
Metano , Oryza , Cromatografia Gasosa/métodos , Ionização de Chama , Gases/análise , Humanos , Metano/análise
7.
Braz. J. Pharm. Sci. (Online) ; 58: e21609, 2022. tab, graf
Artigo em Inglês | LILACS | ID: biblio-1420501

RESUMO

Abstract The potential of the biome caatinga (exclusive from northeastern Brazil) has been evaluated in recent research for application in the pharmaceutical industry. Among the species of medicinal plants from caatinga, one can highlight the Commiphora leptophloeos (umburana), which has been used as infusions and syrups by the regional population for inflammatory and infectious diseases. Essential oils from umburana leaves and barks were obtained in a Clevenger apparatus and analyzed by gas chromatography/mass spectrometry, and total phenolic and flavonoids were determined by spectrophotometric analysis. It was observed that a large part of the major compounds present in the essential oil is described as having antitumor activity, enabling research in investigational oncology with umburana (C. leptophloeos). In addition, some little explored components have been identified, such as cadinene, alpha-selinene, and elemenone. Despite being easily found in several plants, there are no clinical trials involving their biological activity in a well-defined isolated form, which could make exploring new studies possible. Furthermore, the presence of phenolic compounds and flavonoids allows future studies about the potential antimicrobial and antioxidant activity.


Assuntos
Plantas Medicinais/classificação , Óleos Voláteis/análise , Folhas de Planta/classificação , Bursera/efeitos adversos , Espectrometria de Massas/métodos , Cromatografia Gasosa/métodos , Indústria Farmacêutica/classificação
8.
Nutrients ; 13(11)2021 Oct 29.
Artigo em Inglês | MEDLINE | ID: mdl-34836142

RESUMO

The nutritional relevance of food compositional data could be improved by taking the bioaccessibility of these constituents into account. A lack of routine methods to assess the bioaccessibility of fatty acids (FAs) in food is one of the limiting factors of doing so. An analytical protocol is proposed for routine assessment of the extent of lipolysis via in vitro digestion simulation methods in food products. The established method provides specific information on each FA individually. Steps of the protocol including the Bligh and Dyer chloroform/methanol/water extraction of esterified and free FAs from in vitro digesta, methyl ester derivatization, and GC-FID analysis were specifically tailored to help routine work and were harmonized with the Infogest in vitro digestion simulation protocol (both v1.0 and v2.0). The method was applied to assess the degree of FA-specific lipolysis in a baked fish (carp) meal and the results showed that the FA composition of the original food significantly differed from that of the distribution of FFAs in the digesta. The use of gastric lipase (in Infogest v2.0 protocol) increased total FA release by 9.5% and its specific impact on palmitic acid was the most prominent.


Assuntos
Cromatografia Gasosa/métodos , Digestão , Ácidos Graxos/análise , Técnicas In Vitro/métodos , Lipólise/efeitos dos fármacos , Ácidos Graxos não Esterificados/análise , Humanos , Modelos Biológicos , Valor Nutritivo , Alimentos Marinhos/análise
9.
Pak J Biol Sci ; 24(3): 357-365, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34486321

RESUMO

<b>Background and Objective:</b> Preservation of agricultural products remains a hallmark of all farmers as a result, both pesticides and herbicides are being applied during planting and after harvesting with the sole aim of maximizing profits. Research had shown the various degree of toxicity of organochlorine pesticides residues, the objective of the research was to identify the organochlorine pesticide residues, analyze their risk assessment vis-a-vis, Hazard Index (HI), Estimate Dietary Intake (EDI), Target Hazard Quotient (THQ) and compare the results with Acceptable Dietary Intake (ADI), Reference dose standard (Rfd) and Maximum Residue Limit (MRL) and characterized the identified organochlorine pesticides residue for their toxicological properties. <b>Materials and Methods:</b> <i>Phaseolus vulgaris</i> were purchased in a local market in Igbara -Oke, Ondo state Nigeria, the sample was powdered using a grinder (Sumeet CM/L 2128945) and solid phase extraction techniques were employed, the extract was subjected to fractionation into two fractions of aliphatic hydrocarbons and the pesticides. The pesticide extract was subjected to characterization using gas chromatography-mass spectrophotometer. <b>Results:</b> Total 4 organochlorine pesticide residues were identified and the contaminant rates (mg kg<sup>1</sup>) were less than 1. Furthermore, EDI values were lower than the ADI, MRL, also, the THQ values were less than 1, an indication that the <i>Phaseolus vulgaris</i> was safe for consumption. <b>Conclusion:</b> The research had shown no toxicity of the <i>Phaseolus vulgaris</i> purchased from the local market and it shows compliance by the local farmers on the application of pesticides to the food crop by obeying the recommended dose.


Assuntos
Hidrocarbonetos Clorados/efeitos adversos , Resíduos de Praguicidas/análise , Phaseolus/metabolismo , Medição de Risco/métodos , Cromatografia Gasosa/métodos , Hidrocarbonetos Clorados/uso terapêutico , Nigéria , Resíduos de Praguicidas/toxicidade , Praguicidas/efeitos adversos
10.
J Chromatogr A ; 1648: 462191, 2021 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-34000596

RESUMO

Consumers are daily exposed to a range of mineral oil hydrocarbons via food consumption. Major sources of MOH in food are packaging and additives, processing aids, and lubricants. In 2019, an EU guidance was released covering specific directions for sampling and analysis of mineral oil saturated hydrocarbons (MOSH) and mineral oil aromatic hydrocarbons (MOAH) in food and food contact materials within the frame of Recommendation (EU) 2017/84 for the monitoring of mineral oils. The parameters required by the guide are increasingly stringent, and coping with this type of analysis is now very challenging. It is within such a context that the present research is confined, inasmuch that it is focused on the construction of a low-cost, lab-made Y-interface for liquid-gas chromatography coupling used for the determination of MOSH and MOAH in foodstuffs. The response ratios of alkanes comprised between C10 and C50 were measured and were comprised between 0.9 and 1.1, with a maximum coefficient of variation of 4% (n = 5). Intermediate precision was evaluated for the fat/oil category during a period of 48 days obtaining a value of 10%. Qualitative and quantitative analysis of both MOSH and MOAH were performed in a single run and in a fully-automated manner. Seventeen different foods were analyzed in order to cover the categories reported in the EU guide. Saturated hydrocarbon contamination was detected only in a few samples (in the range 1-153 ppm); MOAH contamination was found only in one sample (sunflower oil: 15 ppm).


Assuntos
Cromatografia Gasosa/métodos , Contaminação de Alimentos/análise , Óleo Mineral/análise , Hidrocarbonetos/análise
11.
Food Chem ; 347: 129030, 2021 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-33515968

RESUMO

A modified quick, easy, cheap, effective, rugged, and safe (QuEChERs) method for determining triazine herbicide residues in bivalves (Mussels, Scallops, Cockles) was developed. The use of molecularly imprinted polymers (MIPs) as a selective purification material during dispersive-solid phase extraction (d-SPE) increased the removal rate of pigments interference. With 4% acidic acetonitrile as the organic modifier, the modified QuEChERs method achieved good extraction rate of herbicide residues. The satisfactory recoveries (80%-118%) and RSDs (1.0%-11.6%) of herbicide residues were obtained at three spiked levels. The limits of quantification of herbicide residues ranged from 0.10 µg/kg to 1.59 µg/kg. Further, the herbicide residues in bivalves collected in the eastern coasts of China was analyzed. The developed QuEChERs procedure coupled with GC-MS/MS was successfully applied to the herbicide residues detection in bivalves, and due to the extensive use of herbicides and the large consumption of bivalves in globally, the ongoing risk evaluation is needed.


Assuntos
Bivalves/química , Resíduos de Praguicidas/análise , Extração em Fase Sólida/métodos , Triazinas/análise , Animais , China , Cromatografia Gasosa/métodos , Herbicidas/análise , Espectrometria de Massas em Tandem/métodos , Triazinas/isolamento & purificação
12.
J Chromatogr A ; 1632: 461596, 2020 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-33045497

RESUMO

Despite nearly 80 years of advancements in gas chromatography (GC), indirect chemical matrix effects (MEs), known as the matrix-induced response enhancement effect, still occur to cause a high bias in the GC analysis of susceptible analytes, unless precautions are taken. Matrix-matched calibration is one common option used in GC to compensate for the MEs, but this approach is usually inconvenient, imprecise, and inefficient. Other options, such as the method of standard additions, surface deactivation techniques, chemical derivatizations, priming the GC, and/or use of internal standards, also have flaws in practice. When methods are accommodating, the use of analyte protectants (APs) can provide the best practical solution to not only overcome MEs, but also to maximize analyte signal by increasing chromatographic and detection efficiencies for the analytes. APs address the source of MEs in every injection by filling active sites in the GC inlet, column, and detector, particularly in GC-MS, rather than the analytes that would otherwise undergo degradation, peak tailing, and/or diminished response due to interactions with the active sites. The addition of an adequate amount of APs (e.g. sugar derivatives) to all calibration standards and final extracts alike often leads to lower detection limits, better accuracy, narrower peaks, and greater robustness than the other options to compensate for MEs in GC. This article consists of a critical review of the scientific literature, proposal of mechanisms and theory, and re-evaluation studies involving APs for the first time in GC-orbitrap and GC-MS/MS with a high-efficiency ion source design. The findings showed that 1 µg each of co-injected shikimic acid and sorbitol in the former case, and 1 µg shikimic acid alone in the latter case, led to high quality results in multi-residue analysis of pesticides and environmental contaminants.


Assuntos
Cromatografia Gasosa/métodos , Calibragem , Cromatografia Gasosa-Espectrometria de Massas , Publicações , Processamento de Sinais Assistido por Computador
13.
J Sep Sci ; 43(15): 3061-3073, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32399997

RESUMO

In the following work, a new method for the analysis of the phthalate monoesters in human urine was reported. Phthalate monoesters are metabolites generated as a result of phthalate exposure. In compliance with the dictates of Green Analytical Chemistry, a rapid and simple protocol was developed and optimized for the quantification of phthalate monoesters (i.e., monoethyl phthalate, monoisobutyl phthalate, mono-n-butyl phthalate, mono-(2-ethylhexyl) phthalate, mono-n-octyl phthalate, monocyclohexyl phthalate, mono-isononyl phthalate) in human urine, which entails preceding derivatization with methyl chloroformate combined with the use of commercial solid phase microextraction and the analysis by gas chromatography-triple quadrupole mass spectrometry. The affinity of the derivatized analytes toward five commercial coatings was evaluated, and in terms of analyte extraction, the best results were reached with the use of the divinylbenzene/carboxen/polydimethylsiloxane fiber. The multivariate approach of experimental design was used to seek for the best working conditions of the derivatization reaction and the solid phase microextraction, thus obtaining the optimum response values. The proposed method was validated according to the guidelines issued by the Food and Drug Administration achieving satisfactory values in terms of linearity, sensitivity, matrix effect, intra- and inter-day accuracy, and precision.


Assuntos
Cromatografia Gasosa/métodos , Ésteres/urina , Ácidos Ftálicos/urina , Microextração em Fase Sólida/métodos , Espectrometria de Massas em Tandem/métodos , Adulto , Feminino , Voluntários Saudáveis , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem
14.
Food Chem ; 322: 126743, 2020 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-32283368

RESUMO

Sensory properties are critical characteristics that determine quality and can be evaluated by trained tasting panels. The panels function as multi-sensor measuring instrument and need the use of reference materials (RMs) for training. The homogeneity between units packaged from a batch of RM can be evaluated by gas chromatography coupled to flame ionization detection (GC-FID), using this instrumental technique as an alternative to sensory analysis. For this purpose, the fingerprint methodology is applied, taking into account that the homogeneity assessment will be based on evaluating the similarity between the fingerprints of the fraction of volatile organic compounds acquired from samples representative of the batch. The proposed methodology is applied with good results to evaluate the homogeneity of several RMs for sensory analysis of virgin olive oil samples, using similarity indices, control charts and exploratory analysis of multivariate data to observe the grouping RM and fingerprint regions representative of each defect.


Assuntos
Cromatografia Gasosa/métodos , Azeite de Oliva/normas , Cromatografia Gasosa/normas , Análise por Conglomerados , Azeite de Oliva/química , Óleos de Plantas/química , Análise de Componente Principal , Padrões de Referência , Compostos Orgânicos Voláteis/análise , Compostos Orgânicos Voláteis/normas
16.
J Chromatogr A ; 1610: 460530, 2020 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-31522802

RESUMO

In this article we describe a method using flow-modulated comprehensive two-dimensional gas chromatography with electron capture detector (FM-GC×GC-ECD) for the determination of polychlorinated biphenyls (PCBs) in complex transformer oils bypassing the need for sample preparation. A two-fold improvement in method development was attained. First, the solvation parameter model (SPM) was used to guide column selection. A highly cohesive ionic liquid-based phase (low l system constant), namely 1,12-di(tripropylphosphonium)dodecane bis(trifluoromethanesulfonyl)imide, was used in the primary stage leading to negligible retention of interfering aliphatic hydrocarbons, which are eluted in the first upper quadrant of the chromatogram. The resulting separation space was used to resolve the critical class of compounds, namely, PCBs and polyaromatic hydrocarbons. Second, a unique combination of column geometries and phase ratios enabled highly efficient reverse fill/flush flow modulation using very low pressure for auxiliary gas flow. The proof of concept method described herein exhibited linearities ranging from 0.990 to 0.994, limits of quantitation (LOQ) from 2.23 and 6.85 µg mL-1, precision below 5% relative standard deviation (RSD), and accuracy from 84.2% to 108.9% showcasing the potential of FM-GC×GC for routine analysis.


Assuntos
Cromatografia Gasosa/métodos , Óleos/química , Bifenilos Policlorados/análise , Reprodutibilidade dos Testes
17.
Artigo em Inglês | MEDLINE | ID: mdl-31877809

RESUMO

The reliable quantification of perfluoroalkyl carboxylic acids (PFCAs) in environmental samples like surface water by using gas chromatography (GC) remains challenging because the polar PFCAs call for derivatization before injection and problems involving the integration of sample pretreatment and derivatization procedures. Here we proposed a cost-effective method for the GC based determination of C4-C12 PFCAs in surface water samples by integrating solid phase extraction and PFCAs anilide derivatization. First, we assessed the performance of different PFCAs derivatization methods, namely esterification and amidation. Esterification was unable to derivatize C4-C6 PFCAs. On the contrary, amidation procedures by using 2,4-difluoroaniline (DFA) and N,N'-dicyclohexylcarbodiimide (DCC) could successfully transform all the PFCA analogs to produce anilide derivatives, which could be easily detected by GC. Then the reaction conditions in the amidation approach were further optimized by using orthogonal design experiments. After optimizing the instrumental parameters of GC, the limits of detection (LOD) of this derivatization method were determined to be 1.14-6.32 µg L-1. Finally, in order to establish an intact method for the quantification of PFCAs in surface water samples, solid phase extraction (SPE) was used for extraction and cleanup, which was further integrated with the subsequent amidation process. The SPE-amidation-GC method was validated for application, with good accuracy and precision reflected by the PFCAs recoveries and derivatization of triplicates. The method reported here could provide a promising and cost-effective alternative for the simultaneous determination of C4-C12 PFCAs in environmental water samples.


Assuntos
Ácidos Carboxílicos/análise , Cromatografia Gasosa/métodos , Monitoramento Ambiental/métodos , Fluorocarbonos/análise , Monitoramento Ambiental/economia
18.
J Pharm Biomed Anal ; 165: 366-373, 2019 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-30580085

RESUMO

Within the pharmaceutical industry, the determination of residual solvents by Gas Chromatography Flame Ionization Detection (GC-FID) is a highly utilized analytical test that often employs helium (He) as the carrier gas. However, many do not realize that helium is a non-renewable resource that will eventually become progressively more difficult to source. In recent years, analytical chemists are increasingly adopting hydrogen (H2) in place of helium for routine GC analysis. In this study, a simple and efficient generic/universal GC-FID method using H2 as the carrier gas has been developed with the capability of baseline resolution of over 30 of the most commonly used solvents in development and manufacturing with a method run time of less than eight minutes. The use of this method for the separation and analysis of solvents within a pharmaceutical manufacturing process is demonstrated with additional method validation data presented using five different diluents as a means to increase flexibility for the chromatographer. Furthermore, it is the recommendation of the authors that the current compendia for residual solvent analysis be updated to allow for hydrogen as a carrier gas. The similarity between He and H2 observed within this study supports the use of hydrogen as a suitable replacement for helium, and an update of the EU and USP compendia for residual solvent analysis should be made to reflect this.


Assuntos
Cromatografia Gasosa/métodos , Ionização de Chama/métodos , Hidrogênio/química , Solventes/análise , Indústria Farmacêutica/métodos , Solventes/química
19.
Environ Sci Pollut Res Int ; 25(34): 34510-34518, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30311117

RESUMO

Production and use of most organochlorine pesticides (OCPs) was banned through the Stockholm Convention on persistent organic pollutants. However, appreciable amounts are still detected in the environment due to their persistence, illegal use, and releases from contaminated soils and obsolete stocks. The present study investigated the levels of OCP residues in Nairobi River. Sediment and water samples were collected from three sites along the river and screened for 17 OCPs using gas chromatography electron capture detector (GC-ECD). Mean pesticide residues ranged from 0.01 to 41.9 µg kg-1 in sediment and below detection limit to 39.7 ng L-1 in water. In sediment α-HCH, ß-HCH, γ-HCH, heptachlor epoxide, and p,p'-DDD were detected in all samples, while α-HCH, γ-HCH, δ-HCH, heptachlor epoxide, endosulfan I, and endrin were detected in all water samples. Levels of OCPs in water were below the WHO maximum allowable limits for surface water. However, values higher than the sediment quality guidelines for sediment samples in Racecourse Road Bridge and Outering Road Bridge were reported, thus confirming the toxicity to aquatic organisms. Consequently, as these compounds are known to bio-accumulate in fatty tissues, continued use of the river water poses a health risk to animals and humans.


Assuntos
Sedimentos Geológicos/análise , Resíduos de Praguicidas/análise , Poluentes Químicos da Água/análise , Cromatografia Gasosa/métodos , Monitoramento Ambiental/métodos , Hexaclorocicloexano/análise , Humanos , Hidrocarbonetos Clorados/análise , Quênia , Medição de Risco , Rios/química
20.
Int Heart J ; 59(4): 808-812, 2018 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-29794390

RESUMO

Exhaled acetone concentration is one of the expected compounds to be a breath biomarker in heart failure. However, it has not been clarified how exhaled acetone concentration changes in clinical course of heart failure.To investigate whether exhaled acetone concentration changes after treatment in acute decompensated heart failure (ADHF).This study included 19 patients with ADHF (ADHF group) and eight patients with stable heart failure (control group). Exhaled acetone was collected from these patients, and the concentration was measured with gas chromatography.The ADHF group had higher heart rates (P = 0.046), higher New York Heart Association class (P < 0.001), higher levels of brain natriuretic peptide (P = 0.026), blood total ketone bodies (P = 0.015), and exhaled acetone concentration (P < 0.001), compared with the control group. In ADHF group, exhaled acetone concentration significantly decreased after treatment (median: 2.40 versus 0.92 ppm, P < 0.001). However, in the control group, exhaled acetone concentration did not significantly change (median: 0.73 versus 0.49 ppm, P = 0.141).In these preliminary findings, exhaled acetone concentration in patients with ADHF drastically decreased by treatment. Serial exhaled acetone measurement might be useful to evaluate the course of ADHF.


Assuntos
Acetona/análise , Insuficiência Cardíaca , Hospitalização/estatística & dados numéricos , Idoso , Biomarcadores/análise , Testes Respiratórios/métodos , Cromatografia Gasosa/métodos , Ecocardiografia , Expiração , Feminino , Insuficiência Cardíaca/diagnóstico , Insuficiência Cardíaca/fisiopatologia , Insuficiência Cardíaca/terapia , Frequência Cardíaca , Humanos , Japão , Masculino , Conduta do Tratamento Medicamentoso , Pessoa de Meia-Idade , Peptídeo Natriurético Encefálico/análise , Eliminação Pulmonar , Reprodutibilidade dos Testes
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