JOURNAL OF CHROMATOGRAPHY A
·
2022
·
IF 4.601
Ruijuan Duan,Meiling Qi
This work presents the investigation of two new pentiptycene (PP)-functionalized triblock copolymers (PEPE1, PEPE2) for gas chromatographic (GC) analyses with an aim to address the separation problems toward analytes of high resemblance in properties and a wide variety of components in complex samples. Up to date, these two materials are not reported in any fields. The PEPE1 and PEPE2 columns showed close column efficiency (above 4000 plates/m) but differed in polarity, morphology and separation performance. As testified by the challenging Grob test mixture, the PEPE1 column exhibited comprehensively higher separation capability than the PEPE2 column and the commercial reference columns. Also, the PEPE1 column achieved high-resolution performance for both apolar and polar isomers of high resemblance, such as xylenes, phenols and anilines. Moreover, it displayed high inertness towards carboxylic acids and excellent separation repeatability and reproducibility tested by the aniline isomers with the RSD values in the range of 0.01–0.04% for run-to-run, 0.09–0.13% for day-to-day and 1.2–2.0% for column-to-column, respectively. Its application to GC–MS analysis of the essential oil from tea flowers demonstrated its advantageous separation performance towards a wide range of components and proved its feasibility for practical analyses of complex samples.
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高影响因子
FUEL
·
2022
·
IF 8.035
Wei Ni,Gangtian Zhu,Fei Liu,Can Xie,Wei Li,Shukui Zhu
Carboxylic acids (CAs) are important molecular markers in petroleum geochemistry, which can indicate the origin, migration and biodegradation of oils. In this work, an easy and fast method was developed for the separation and analysis of CAs in crude oils by the combination of gas purge microsyringe extraction (GP-MSE) and comprehensive two-dimensional gas chromatography-mass spectrometry (GC × GC–MS). CAs in oils were firstly reacted with a silylation reagent to improve their volatility and thermal stability. The silylated CAs were then separated from oils together with light hydrocarbons with GP-MSE treatment at a relatively low temperature (200 °C). Subsequently, direct analysis of the extract solutions by GC × GC–MS was performed. Profited from the extremely high peak capacity of GC × GC, the signals of silylated CAs could be easily distinguished from hydrocarbon signals. Under optimal conditions, the extraction time and the solvent consumption of GP-MSE were 8 min and 150 μL, respectively. In the analysis of reservoir crude oils with different biodegradation degrees, abundant CA signals were successfully detected, and the contents of CAs were found to vary regularly with the biodegradation degree.
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MICROCHEMICAL JOURNAL
·
2023
·
IF 4.8
Ruiyu Fu,Tingze Ren,Yanhui Zhang,Qingxin Lu,Xiaoli Guo,Xin Di
A new supramolecular solvent (SUPRAS) was synthesized using hexafluoroisopropanol (HFIP) as hydrogen bond donor and undecanol as hydrogen bond acceptor. Then SUPRAS was used as extraction solvent to enrich triazole fungicides in drinking water and beverages by liquid phase microextraction (LPME). Additionally, several variables that influence extraction efficiency were optimized, and the significant factors were investigated by Box-Behnken design. At optimum condition, the method shows desirable precision (RSDs less than 19.4%) and acceptable recovery (63.4%-112.1%). The low limits of detection and limits of quantitation of this method were found to be in the range of 1.0–5.0 μg/L and 5.0–20 μg/L, respectively. Compared with other analytical techniques, the method demonstrated comparable sensitivity, consumed less extractant (750 μL) and a shorter pre-treatment time (10 min). The formation mechanism of SUPRAS was investigated by density functional theory. The proposed methodology was green, sensitive, time-saving and successfully applied to determine triazole fungicides in drinking water and beverages, making it an alternative technique for the analysis of trace analytes with satisfactory sensitivity.
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BIOTECHNOLOGY AND APPLIED BIOCHEMISTRY
·
2023
·Vol. 70
·期 6
·1806-1816
·
IF 2.8
Jing Zhou,Si-Jia Miao,Shi-Zhong Yang,Jin-Feng Liu,Hong-Ze Gang,Bo-Zhong Mu
Rhamnolipid, as a low-toxic, biodegradable and environmentally friendly biosurfactant, has broad application prospects in many industries. However, the quantitative determination of rhamnolipid is still a challenging task. Here, a new sensitive method for the quantitative analysis of rhamnolipid based on a simple derivatization reaction was developed. In this study, 3-[3′-( l -rhamnopyranosyloxy) decanoyloxy] decanoic acid (Rha-C10-C10) and 3-[3′-(2′- O -α- l -rhamnopyranosyloxy) decanoyloxy] decanoic acid (Rha-Rha-C10-C10) were utilized as the representative rhamnolipids. Liquid chromatography–mass spectrometry and high-performance liquid chromatography-ultra violet results showed that these two compounds were successfully labeled with 1 N1-(4-nitrophenyl)-1,2-ethylenediamine. There was an excellent linear relationship between rhamnolipid concentration and peak area of labeled rhamnolipid. The detection limits of the Rha-C10-C10 and Rha-Rha-C10-C10 were 0.018 mg/L (36 nmol/L) and 0.014 mg/L (22 nmol/L), respectively. The established amidation method was suitable for the accurate analysis of rhamnolipids in the biotechnological process. The method had good reproducibility with the relative standard deviation of 0.96% and 0.79%, respectively, and sufficient accuracy with a recovery of 96%–100%. This method was applied to quantitative analysis of 10 rhamnolipid homologs metabolized by Pseudomonas aeruginosa LJ-8. The single labeling method was used for the quantitative analysis of multiple components, which provided an effective method for the quality evaluation of other glycolipids with carboxyl groups.
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MOLECULES
·
2023
·Vol. 28
·期 22
·7634
·
IF 4.6
Hongbo Yang,Jin Li,Jianfei Mao,Chan Xu,Jieyu Song,Feng Xie
Ochratoxins, a common class of mycotoxin in capsicum, and techniques and methods for the determination of mycotoxins in spices have been increasingly developed in recent years. An innovative and eco-friendly method of dispersive liquid–liquid microextraction (DLLME) was demonstrated in this study, based on a synthesized deep eutectic solvent (DES) combined with LC-MS/MS, for the quantification and analysis of two ochratoxins in capsicum. The DES-DLLME method parameters entail selecting the DES type (thymol:decanoic acid, molar ratio 1:1) and DES volume (100 μL). The volume of water (3 mL) and salt concentration (0 g) undergo optimization following a step-by-step approach to achieve optimal target substance extraction efficiency. The matrix effect associated with the direct detection of the target substance in capsicum was significantly reduced in this study by the addition of isotopic internal standards corresponding to the target substance. This facilitated optimal conditions wherein quantitative analysis using LC-MS/MS revealed a linear range of 0.50–250.00 µg/mL, with all two curves calibrated with internal standards showing correlation coefficients (r2) greater than 0.9995. The method’s limits of detection (LODs) and limits of quantification (LOQs) fell in the ranges of 0.14–0.45 μg/kg and 0.45–1.45 μg/kg, respectively. The method’s spiked recoveries ranged from 81.97 to 105.17%, indicating its sensitivity and accuracy. The environmental friendliness of the technique was assessed using two green assessment tools, AGREE and complexGAPI, and the results showed that the technique was more in line with the concept of sustainable development compared to other techniques for detecting ochratoxins in capsicum. Overall, this study provides a new approach for the determination of mycotoxins in a complex food matrix such as capsicum and other spices using DES and also contributes to the application of green analytical chemistry methods in the food industry.Keywords:deep eutectic solvent;dispersive liquid–liquid microextraction;ochratoxins;capsicum;green analytical chemistry
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Journal of Cleaner Production
·
2023
·
IF 11.1
Lu Huang,Yingjie Guo,Tianqi Jin,Ke Yan,Xianglin Liu,Shuyang He,Lin Li,Ye Gong,Junyi Ma,Hang Yu,Zhoumin Lu,Yupeng Liu,Wuzi Dong,Fangxia Yang
Triterpene acids (TTAs) have promising applications in functional food, medicine and other fields. Here, ultrasonic-assisted hydrophobic deep eutectic solvent (HDES) extraction was employed to gain TTAs from loquat leaves. Combining COSMO-SAC model prediction with experimental verification，the HDES, composed of thymol and benzyl alcohol (molar ratio 2:1), was proved to have the highest extraction ability for TTAs. The preliminarily optimized extraction conditions were solid to solvent ratio 1:10 (g/g), temperature 60 °C and extraction time 60 min. Under these conditions, the extraction yield of ursolic acid (the main component of loquat leaf TTAs) was 17.769 ± 0.799 mg/g dry loquat leaf. HDES and TTAs were recovered from HDES extracting solution via gradient elution (60% and 80% ethanol aqueous solution, respectively) based on C18 reverse-phase silica gel column chromatography under low pressure (0.5 MPa). Recovered HDES could be reused for extracting TTAs from loquat leaves directly and had a similar extraction performance compared to fresh HDES. The purity of the obtained crude TTAs sample was 81.18% based on the total contents of maslinic acid (MA), corosolic acid (CA), oleanolic acid (OA) and ursolic acid (UA), with a mass ratio of 11:26:10:53. Crude TTAs sample was further separated by C18 reverse-phase silica gel column chromatography using 80% ethanol aqueous solution as mobile phase under high pressure (15 Mpa). By this mean, CA sample with 69.30% purity (MA to CA mass ratio 7:18) and UA sample with 93.94% purity (OA to UA mass ratio 4:21) were obtained. The in vitro antioxidant ability order of the attained TTAs samples was CA sample > crude TTAs sample > UA sample. This study laid a good scientific basis for applying HDES and C18 reverse-phase silica gel column chromatography in the bioactive component extraction and separation fields. It also provided theoretical basis and technical support for obtainment and utilization of high-purity loquat leaf TTAs in the fields of medicine, functional food, cosmetics and so on.
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FOOD CHEMISTRY
·
2023
·
IF 8.8
Xingle Guo,Xiaojiao Zheng,Xu Guo,Junxue Wu,Xu Jing
Emulsive liquid–liquid microextraction (ELLME), a simple, rapid, and environmentally friendly technique, was established to identify chiral prothioconazole and its chiral metabolite in water, juice, tea, and vinegar using ultra-high-performance liquid chromatography (UPLC). Environmentally friendly extractant was mixed with pure water to prepare a high-concentration emulsion, which was added to samples to complete the emulsification and extraction in 1 s. Afterward, an electrolyte solution was added to complete the demulsification without centrifugation. ELLME did not use dispersants compared to the familiar dispersive liquid–liquid microextraction (DLLME), thus reducing the use of toxic solvents and avoiding the effect of dispersants on the partition coefficient. The linear range was from 0.01 to 1 mg/L. The limit of detection was 0.003 mg/L. The extraction recoveries ranged from 82.4 % to 101.6 %, with relative standard deviations of 0.7–5.2 %. The ELLME method developed has the potential to serve as an alternative to DLLME.
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LANGMUIR
·
2023
·
IF 3.9
Longnan Yu,Sihao Li,Yan Lu,Zhongping Wang,Mingming Fu,Sheng Wei,Changgang Xu,Qing Wang,Xiaoqing Liu,Li Wang
The delicate regulation of structural phase transition can provide advanced approaches for fabricating desired and well-organized nanoarchitectures on surfaces. Introduction of metal ions into pure organic systems can facilitate the phase transition from hydrogen-bonded structures to metal–organic structures by coordinating with organic molecules. However, it remains a challenge to attain a phase transition dominated by variable metal coordination configurations through adjustment of the metal ion concentration. Herein, we report the phase transitions of naphthalene-2,3-carbonitride (2,3-DCN) molecules on highly oriented pyrolytic graphite (HOPG) under varying solvents and Cu2+ ion concentrations. By integrating data from scanning tunneling microscopy imaging and density functional theory calculations, it is demonstrated that phase transitions of 2,3-DCN occur through forming diverse coordination configurations where Cu2+ ions can coordinate with 2,3-DCN and 1-nonanoic acid or Cl– ions to form different ligand components with a coordination number of 4 when varying the molar ratios of 2,3-DCN to Cu2+ ion in the 1-nonanoic acid solvent. However, in the case of 1-heptanoic acid as a solvent, the self-assembly structure of 2,3-DCN only changes via the alteration of hydrogen bonding sites and Cu2+ ions do not coordinate with 2,3-DCN molecules. These findings provide valuable insights into the coordination behavior of metal ions in different solvents.
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JOURNAL OF FOOD SCIENCE
·
2021
·Vol. 86
·期 11
·4932-4945
·
IF 3.167
Yuan Chang,Shuqi Wang,Haitao Chen,Ning Zhang,Jie Sun
The solvent-assisted flavor evaporation, sensory evaluation, and partial least squares regression analysis were used to screen the relatively better flavor of pork broth among different stewing time (1, 2, 4, 6, and 8 h). A total of 48 volatile compounds were successfully characterized by gas chromatography-mass spectrometry in the pork broth, which stewed for 4 h. The dominant volatiles were confirmed by aroma extract dilution analysis. Twenty-seven odorants with flavor dilution factors between 2 and 1,024 were identified. Among them, odor activity values of 19 components were greater than or equal to 1. An aroma recombination test was performed, and a similar flavor (93.04 %) was simulated. Omission test further confirmed that 4-hydroxy-2,5-dimethyl-3(2H)-furanone, hexanal, 1-octen-3-ol, ( E )-2-octenal, ( E )-2-decenal, ( E )-2-undecanal, ( E, E )-2,4-decadienal, nonanoic acid, decanoic acid, 2-heptanone, 3-hydroxy-2-butanone, δ -decanolactone, and 2-acetylpyrrole were the key odorants of the aroma profile of pork broth. Practical Application Pork broth is popular in China, but lacks the study of its key aroma compounds, which restricts its industrial production. This study researched the optimum stewing time of pork broth and analyzed its key aroma compounds. Finally, the flavor profile can be obtained and understood. This study could provide a reference and further promote research on pork flavor.
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FOOD CHEMISTRY
·
2021
·
IF 7.514
Tong Wang,Qing Wang,Qing Guo,Ping Li,Hua Yang
Green extraction and separation of natural products is crucial for food industry, and has been widely concerned. Compared with hydrophilic natural products, the green extraction and separation of hydrophobic natural products is more challenging. In this work, a novel method which coupled the ultrasound-assisted extraction with high-speed countercurrent chromatography (HSCCC) separation based on hydrophobic deep eutectic solvent (DES) was proposed for hydrophobic compounds extraction and recovery. By using the developed method, the hydrophobic compounds in Rosmarinus officinalis leaves , Ginkgo biloba leaves and Salvia miltiorrhiza roots have been successfully extracted and recovered. The results indicated that hydrophobic DESs are more effective for extraction hydrophobic compounds than hydrophilic DESs and traditional solvents. And hydrophobic DESs can be used as HSCCC separation solvents to separate and recover hydrophobic compounds effectively. The infinite possibilities of DESs components and their combinations can provide inexhaustible selective space for hydrophobic compounds in the HSCCC separation process.
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Food Additives and Contaminants Part A-Chemistry Analysis Control Exposure & Risk Assessment
·
2020
·
IF 2.34
Xin Huang,Zhiyi Du,Beiqi Wu,Liyan Jia,Xiaowen Wang,Xu Jing
In this paper, a dispersive liquid–liquid microextraction method based on the solidification of floating organic droplets, combined with high-performance liquid chromatography (DLLME-SFOD-HPLC), was developed for the detection of strobilurin fungicides (azoxystrobin, pyraclostrobin, and trifloxystrobin) in cereals. Natural fatty acids were used as an extractant and have low toxicity, density, and freezing point. The extractant nonanoic acid was evenly dispersed as droplets in sample solution and was then solidified in the upper layer of sample solution after centrifugation and ice bath, which improved the extraction and collection efficiency. The dispersive liquid-liquid microextraction procedure was optimised by univariate analysis and the Box-Behnken response surface methodology. Optimum conditions were as follows: the volume of nonanoic acid was 82 μL, the volume of acetonitrile was 620 μL, and the amount of salt was 256 mg. Under optimised conditions, the method had good linearity with a correlation coefficient higher than 0.997, and the limit of detection was 2.57–4.87 μg kg−1. The recoveries of azoxystrobin, pyraclostrobin, and trifloxystrobin in rice, corn, and wheat were 82.0%-93.2%, and the relative standard deviations were 1.6%-7.4%. Therefore, the method was successfully applied to detect target fungicides in cereals.
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JOURNAL OF CHROMATOGRAPHIC SCIENCE
·
2020
·Vol. 58
·期 9
·880-886
·
IF 1.28
Li Xiao,Yuan Tao,Zhao Ting,Wu Xiaomei,Yang Yaling
An environmentally friendly method for the determination of testosterone and methyltestosterone by acid–base-induced deep eutectic solvents liquid–liquid microextraction (DES-ABLLME) combining with high-performance liquid chromatography was established. The deep eutectic solvent (DES) consisting of menthol:lauric acid:decanoic acid (3:1:1) can act as both hydrogen bond donor and hydrogen bond acceptor. In this approach, ammonia solution (NH3•H2O) is used as an emulsifier to react with DESs in the extraction process to generate salt and form milky white solution, achieving high extraction efficiency. Hydrochloric acid was used as a phase separator to change the emulsification state and promote the separation of extraction agent from water phase. A series of parameters were optimized including the volume of DES and the emulsifying agent, glucose concentration as well as hydrochloric acid volume. The method was linear in the range 0.5–100 μg mL−1 with a correlation coefficient (R) of 0.9999, and the limits of detection were 0.067 and 0.2 μg mL−1 for testosterone and methyltestosterone, respectively. This method was applied to analyze testosterone and methyltestosterone in milk samples, and the recoveries were between 89.2 and 108.2%.
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