Cogent Chemistry最新文献_第2页

Determination of ethanol in blood using headspace gas chromatography with flameionization detector (HS-GC-FID): Validation of a method 顶空气相色谱-火焰化检测器(HS-GC-FID)测定血液中乙醇的方法验证

Cogent Chemistry Pub Date : 2020-01-01 DOI: 10.1080/23312009.2020.1760187

L. D. Mihretu, Asfaw Gebretsadik Gebru, K. Mekonnen, Abraha Gebrekidan Asgedom, Ykalo Hadush Desta

{"title":"Determination of ethanol in blood using headspace gas chromatography with flameionization detector (HS-GC-FID): Validation of a method","authors":"L. D. Mihretu, Asfaw Gebretsadik Gebru, K. Mekonnen, Abraha Gebrekidan Asgedom, Ykalo Hadush Desta","doi":"10.1080/23312009.2020.1760187","DOIUrl":"https://doi.org/10.1080/23312009.2020.1760187","url":null,"abstract":"Abstract Ethanol is a common psychoactive substance that has been widely consumed in several parts of the world. Gas chromatography (GC) coupled with flame ionisation detector (FID) has often been used for the determination of blood alcohol concentration. The aim of this study was to develop and validate a very simple and reliable HS-GC-FID method for quantitative determination of ethanol in blood sample. Validation of the method was performed by means of Bias, Linearity, LOD, Selectivity, Specificity, Precision, Robustness and Intermediate precision. The method showed an excellent linearity with correlation coefficient (r2 = 0.993) was observed in the range from 0.1 to 3.5 mg/mL of ethanol. The percent recovery value were between 91.0 and 109.1 which was with an acceptable percent recovery, The precision (repeatability) was reported as 27 % and intermediate precision of the method resulted in 11% and 1 % for two analysts. The limit of detection (LOD) of ethanol was calculated as 0.099 mg/mL and the selectivity of the method for interferents (methanol and acetaldehyde) was totally selective. Generally, the results obtained confirmed that the method is relatively fast, precise, simple, robust and can be used in routine forensic analyses for the determination of blood alcohol concentration (BAC) at a concentration level greater than 0.13 mg/mL.","PeriodicalId":10640,"journal":{"name":"Cogent Chemistry","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/23312009.2020.1760187","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48257682","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 9

Statistical analysis of trace metals content of cocaine using inductively coupled plasma-mass spectrometry calibrations 电感耦合等离子体质谱法校正可卡因痕量金属含量的统计分析

Cogent Chemistry Pub Date : 2019-01-01 DOI: 10.1080/23312009.2019.1671071

Edward Bentil, N. Asiedu, James Ataki

{"title":"Statistical analysis of trace metals content of cocaine using inductively coupled plasma-mass spectrometry calibrations","authors":"Edward Bentil, N. Asiedu, James Ataki","doi":"10.1080/23312009.2019.1671071","DOIUrl":"https://doi.org/10.1080/23312009.2019.1671071","url":null,"abstract":"Abstract The trafficking of cocaine has become a global challenge now and Ghana is no exception. Cocaine is a whitish powder, which is, produced both from natural and synthetic means. This paper studied the metal content of seized cocaine in Ghana and the data used for batch identification. Ten metals, namely, Pb, Cu, Mg, Mn, Cr, As, Ni, Fe, Co and Ca were analyzed in 37 samples which were sampled from 2010 to 2014. Analyses of the metals were done using ICP-MS and data was analyzed using statistical tools. The results showed that, calcium recorded the highest amount in all the samples with a mean of 64.94mg/kg followed by Magnesium, Zinc and Iron with mean values of 24.35mg/kg, 6.25mg/kg and 2.65mg/kg, respectively. All the samples, within-seizure classification under class A showed to significant differences between each pair at a confidence level of 95%. With three sample pairs under class B in the within-seizure classification, one of the pairs; 103A and 105B showed no significant differences between them even though they were sampled from two different packages from the same seizure. Five samples from five different seizures also showed a significant difference among them showing that they came from different batches or origin. It is confirmed that seized cocaine contained poisonous heavy metals like Lead, Arsenic and Chromium, which have the amount that could affect the user-provide figures. Based on the data gathered from the within-seizure class A group, it could be proposed that a missing cocaine could be identified by its metal content.","PeriodicalId":10640,"journal":{"name":"Cogent Chemistry","volume":"5 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/23312009.2019.1671071","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43092524","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

Calibration development for nutritional evaluation of Yam (Dioscorea sp.) using Near-Infrared Reflectance Spectrophotometry (NIRS) 近红外反射分光光度法用于薯蓣营养评价的标定方法研究

Cogent Chemistry Pub Date : 2019-01-01 DOI: 10.1080/23312009.2019.1565623

O. E. Alamu, M. Adesokan, B. Maziya-Dixon

{"title":"Calibration development for nutritional evaluation of Yam (Dioscorea sp.) using Near-Infrared Reflectance Spectrophotometry (NIRS)","authors":"O. E. Alamu, M. Adesokan, B. Maziya-Dixon","doi":"10.1080/23312009.2019.1565623","DOIUrl":"https://doi.org/10.1080/23312009.2019.1565623","url":null,"abstract":"Abstract The aim of yam breeders is to produce many hybrids, which can form the basis of selecting quality nutritional traits and other characteristics using certain agronomic criteria. Chemical methods are employed to determine the main constituents of yam, which are time-consuming, expensive, and involve sample destruction. However, the constraints of lengthy analysis time and the cost needed to analyze thousands of these genotypes are major constraints to yam breeding in Nigeria. This study was undertaken to develop and validate calibration equations on the Near-Infrared Reflectance Spectrophotometer (NIRS) for determining chemical compositions of selected yam genotypes. Equations developed for moisture, ash, protein, crude fiber, and tannin showed high coefficients of determination (R2) for the calibration curve (0.87, 0.84, 0.83, 0.80, and 0.89, respectively) and high to medium coefficients of determination in cross-validation (0.80, 0.68, 0.69, 0.68, and 0.50). The standard errors of calibration (SEC) and the standard errors in cross-validation (SECV) were low for most constituents. A total of 360 ascensions of yam flour were predicted for selected traits to test the equations, and the results were comparable with data from conventional methods. Results of this study have shown that NIRS could be a very useful tool to help yam breeders screen large sample sets using limited resources with very short time. This will enhance breeders’ rapid selection of genotypes at screening stage where many breeding lines are to be evaluated within the shortest time possible.","PeriodicalId":10640,"journal":{"name":"Cogent Chemistry","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/23312009.2019.1565623","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46536104","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 10

A comparison of the transition metal concentrations in the faeces, urine, and manure slurry from different livestock animals related to environmentally relevant microbial processes 与环境相关的微生物过程有关的不同家畜的粪便、尿液和粪肥浆中过渡金属浓度的比较

Cogent Chemistry Pub Date : 2019-01-01 DOI: 10.1080/23312009.2019.1644702

S. Svane, H. Karring

{"title":"A comparison of the transition metal concentrations in the faeces, urine, and manure slurry from different livestock animals related to environmentally relevant microbial processes","authors":"S. Svane, H. Karring","doi":"10.1080/23312009.2019.1644702","DOIUrl":"https://doi.org/10.1080/23312009.2019.1644702","url":null,"abstract":"Abstract The microbiological communities in livestock manure slurries produce gases of environmental concern such as ammonia, methane and nitrous oxide and require trace metals such as nickel, iron, and copper to synthesize active metalloenzymes that catalyse key biochemical reactions. Additionally, large quantities of trace metals are supplied to the soil when animal manure/manure slurry is used as a fertilizer, which has led to more strict legislation regarding metal contents in manure slurry. In this study, the concentrations of the environmentally relevant transition metals nickel (Ni), copper (Cu), zinc (Zn), iron (Fe), and manganese (Mn) in faeces and urine from pigs, cattle and horses were determined using graphite furnace and flame atomic absorption spectroscopy. We show that for all three animal species 97–100% of the metal contents in manure slurry originate from faeces. The analyses show that uncontaminated manure slurry from pigs has higher metal contents than the manure slurries from cattle and horses. Specifically, on a dry matter (dm) basis, pig manure slurry contains approximately 8 mg Ni/kg dm, 104 mg Cu/kg dm, 185 mg Zn/kg dm, 1134 mg Fe/kg dm, and 356 mg Mn/kg dm. Comparing the determined transition metal contents with published values for manure/manure slurry reveals that especially Cu, Zn and Fe concentrations in manure slurry have decreased in recent years. Comparing our results with other observations suggest that the levels of Ni, Cu, Zn, Fe, and Mn in manure slurries do not limit the microbial processes involved in the production or assimilation of environmentally relevant biogenic gasses.","PeriodicalId":10640,"journal":{"name":"Cogent Chemistry","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/23312009.2019.1644702","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47075110","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 11

Voltammetric determination of paracetamol in pharmaceutical tablet samples using anthraquinone modified carbon paste electrode 蒽醌修饰碳糊电极伏安法测定片剂中扑热息痛的含量

Cogent Chemistry Pub Date : 2019-01-01 DOI: 10.1080/23312009.2019.1576349

Meareg Amare, Welday Teklay

{"title":"Voltammetric determination of paracetamol in pharmaceutical tablet samples using anthraquinone modified carbon paste electrode","authors":"Meareg Amare, Welday Teklay","doi":"10.1080/23312009.2019.1576349","DOIUrl":"https://doi.org/10.1080/23312009.2019.1576349","url":null,"abstract":"Abstract After cyclic voltammetric investigation of the electrochemical behavior of paracetamol and dependence of peak current on scan rate and pH; square wave voltammetric method based on anthraquinone modified carbon paste electrode was developed for direct determination of paracetamol in pharmaceutical tablet samples. In contrast to the peak potential at the unmodified electrode, appearance of the oxidative peak at a lower potential at the modified electrode indicated a catalytic property of the modifier towards paracetamol oxidation. While the observed peak potential shift with scan rate confirmed the irreversibility of the reaction, comparable correlation coefficients for the dependence of peak current of scan rate and square root of scan rate indicated that the irreversible oxidation reaction was controlled by both diffusion and adsorption. The peak current response of the developed method showed a linear dependence on the paracetamol concentration in the range 5 to 150 ppm. Excellent recoveries (93.5%), wide dynamic range, low limit of detection (0.13 µM), and limit of quantification (0.43 µM) validated the method for determination of paracetamol in real samples. The proposed method was applied for paracetamol determination in four brands of tablet samples (Julphare Aldol, Panadol Adva, Kelvin, and Para Denk) all of which labeled 500 mg/tablet. The paracetamol content of the analyzed four brands of tablet samples using the reported method was ranged between 83.04% (Panadol Adva, Kenya) and 95.08% (Para Denk, Germany) of the labeled amount. The discrepancy might be ascribed to the possible matrix difference among the companies and/or failure of the companies to comply the standard.","PeriodicalId":10640,"journal":{"name":"Cogent Chemistry","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/23312009.2019.1576349","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48486426","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 19

Palladium-catalyzed amination of 2-chlorothienopyridone with primary aromatic amines 钯催化2-氯噻吩并吡啶酮与伯芳香胺的胺化反应

Cogent Chemistry Pub Date : 2019-01-01 DOI: 10.1080/23312009.2019.1567894

Samir A. Al-taweel, Salah A Al-Trawneh, Wal'A M. Al-Trawneh

引用次数: 1

AmberliteTM IRA67: A novel and efficient ion exchange resin catalyst for the synthesis of 1, 8-dioxoxanthene derivatives AmberliteTM IRA67：一种新型高效离子交换树脂催化剂，用于合成1,8-二氧杂蒽衍生物

Cogent Chemistry Pub Date : 2019-01-01 DOI: 10.1080/23312009.2019.1708160

N. Babu G., W. Belay, Teju Endale

{"title":"AmberliteTM IRA67: A novel and efficient ion exchange resin catalyst for the synthesis of 1, 8-dioxoxanthene derivatives","authors":"N. Babu G., W. Belay, Teju Endale","doi":"10.1080/23312009.2019.1708160","DOIUrl":"https://doi.org/10.1080/23312009.2019.1708160","url":null,"abstract":"Abstract The catalytic performance of AmberliteTM IRA67, the heterogeneous weak Base Exchange resin which bears tertiary amine functional group, for the synthesis of 1, 8-dioxoxanthene derivatives were investigated. The AmberliteTM IRA67 heterogeneous resin catalyst was found to be efficient and easily recoverable in the reaction of aromatic aldehydes and 5,5-dimethyl-1,3-cyclohexanedione to their corresponding 1, 8-dioxoxanthene derivatives under novel reaction conditions. Short reaction times, excellent yields (88–98%) and simple experimental procedure with an easy work-up are some of the advantages of the procedure. A total of 11 new compounds have been synthesized with a variety of substituent. The characterization of the compounds was completed using melting point determination, FT-IR, 1H-NMR, and 13C-NMR spectroscopic methods. The AmberliteTM IRA67 catalyst could be easily recovered after reaction completion and reused six times with an excellent durability and without any noticeable loss in activity. Furthermore, this general and simple method may be of much significance in many of other catalytic applications. Graphical Abstract","PeriodicalId":10640,"journal":{"name":"Cogent Chemistry","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/23312009.2019.1708160","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47952861","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 4

Electrochemical determination of paracetamol, rutin and sulfonamide in pharmaceutical formulations by using glassy carbon electrode – A Review 玻璃碳电极电化学测定药物制剂中扑热息痛、芦丁和磺胺的研究进展

Cogent Chemistry Pub Date : 2019-01-01 DOI: 10.1080/23312009.2019.1681607

A. Kassa, Meareg Amare

引用次数: 12

Modelling the distribution of arsenic and mercury in urine using chemometric tools 利用化学计量工具模拟尿液中砷和汞的分布

Cogent Chemistry Pub Date : 2019-01-01 DOI: 10.1080/23312009.2019.1586064

Bernard Adu-Poku, N. Asiedu, O. Akoto, James Ataki

{"title":"Modelling the distribution of arsenic and mercury in urine using chemometric tools","authors":"Bernard Adu-Poku, N. Asiedu, O. Akoto, James Ataki","doi":"10.1080/23312009.2019.1586064","DOIUrl":"https://doi.org/10.1080/23312009.2019.1586064","url":null,"abstract":"Abstract Among the heavy metals and other chemicals that contaminate the immediate environment of all gold mining communities, Arsenic and Mercury compounds are some of the most prevalent, exposing residents to their health risks. This menace is the result of the mining activities, particularly, Artisanal and Small-scale gold mining, in these communities. Among the mining areas in Ghana, Artisanal and small-scale gold mining is a recent activity only in the Eastern Region, particularly in the Aduasena, Afosu, Intronang, Hweakwae, New Abirem, Mamano and Hamlets communities. The objective of this research is to investigate the levels of Arsenic and Mercury in the residents of these seven communities using spectroscopic analysis of their urine samples and to identify which gender and at what age does any resident in a typical Ghanaian mining community stand most endangered by the levels of these contaminants. Samples of first urine void of residents upon waking up in the morning were taken, digested with nitric acid and analysed for the concentrations of Arsenic and Mercury using the Perkin Elmer PinAAcle 900T Graphite Furnace AAS. The spectroscopic analysis of the urine samples showed that more than 20% of the residents had concentrations of Arsenic higher than the (normal) recommended level, with some reaching as high as 221 for Arsenic and 3.90 for mercury. Statistical analysis of the results showed that the levels of both Arsenic and Mercury seem to increase with increasing age, despite some extremely high concentrations for arsenic in the Aduasena youth between 31 and 40 years. This trend indicates that males were seen to be more at risk from these contaminants, with the youth between 11 and 20 years standing most endangered.","PeriodicalId":10640,"journal":{"name":"Cogent Chemistry","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/23312009.2019.1586064","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47738050","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 4

Erratum 勘误表

Cogent Chemistry Pub Date : 2018-01-01 DOI: 10.1080/23312009.2018.1457128

V. E. Tarabanko

引用次数: 3