FOOD CHEMISTRY
·
2014
·
IF 3.259
Peijin Wang,Yu Xiao,Wenjun Liu,Juan Wang,Yaling Yang
A rapid, simple, sensitive and environmentally friendly method has been developed for the determination of three oestrogens (17β-estradiol (17β-E2), estrone (E1), and diethylstilbestrol (DES)) in milk samples by using vortex-assisted hollow fibre liquid-phase microextraction (VA-HF-LPME) and high performance liquid chromatography. Method is based on the microextraction of oestrogens from sample solution into 15 μL of nonanoic acid as extracting agent, which is placed inside the hollow fibre followed by vortex-mixing. Vortex provided effective and mild mixing of sample solution and increased the contact between analytes and boundary layers of the hollow fibre, thereby enhancing mass transfer rate and leading to high recovery of target analytes. The extraction equilibrium is achieved within 2 min. Parameters influencing the recovery were investigated and optimized. The proposed technique provided good linearity (>0.9984), repeatability (RSD = 2.56–4.38), low limits of detection (0.06–0.17 ng mL −1 ), and high enrichment factor (330).
研究领域:
分析化学
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环境科学
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产品关联
DOI
PubMed
高影响因子
Crystals
·
2023
·Vol. 13
·期 7
·1099
·
IF 2.7
Li He,Niansheng Huang,Donglin Lu,Pengfei Sheng,Wenjing Zou
Due to its high bonding energy and low self-diffusion coefficient, silicon nitride (Si3N4) ceramics cannot form a dense structure with prolonged high-temperature insulation or by raising the sintering temperature. To improve the density of the sintered Si3N4ceramics, additives are added to promote the rearrangement–dissolution–precipitation process of the crystal grains. However, the liquid phase formation temperature of different sintering aid chemical compositions varies, making it challenging to isolate the mechanism and the effect of liquid phase formation temperatures on sintering. Hence, we developed three sintering aids, namely Y2O3-Al2O3(YA), Y2Si2O7(Y2S), and Y2Si2O7-Al6Si2O13(Y2SM), with homologous elements and different liquid phase formation temperatures. These sintering aids can form a liquid phase with SiO2on the surface of Si3N4at varying temperatures. We analyzed the sintered Si3N4ceramic’s density, volume shrinkage rate, and microstructure to verify the YA’s lower liquid phase formation temperature effect, providing more rearrangement time and increasing sintering density. Conversely, sintering aids with too low liquid phase formation temperatures are more prone to volatilize during high-temperature sintering stages, thereby reducing sintering density. This research found that different liquid phase formation temperatures do not affect the α→β phase transition temperature of Si3N4ceramics. We also evaluated the Y2S sintering aid contents’ effect on Si3N4ceramics sintering. The results revealed that aiding sintering with too little Y2S content is insufficient for liquid phase production, and hence does not improve sintering density. Conversely, excessive liquid phase can improve density and refine grain size but increases weight loss rate during sintering due to volatilization.Keywords:liquid phase sintering;liquid phase formation temperature;sintering aids;silicon nitride sintering
研究领域:
材料科学
·
陶瓷工程
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DOI
高影响因子
JOURNAL OF CHROMATOGRAPHIC SCIENCE
·
2014
·Vol. 53
·期 5
·830-835
·
IF 1.026
Zhou Yuxia,Zou Qiaogen,Sun Lili,Wei Ping,Ouyang Pingkai
Dispersive liquid–liquid microextraction based on the solidification of a floating organic droplet combined with high-performance liquid chromatography with ultraviolet detection (HPLC-UV) was developed for the determination of clevidipine and its primary metabolite in Sprague-Dawley rat plasma samples. During the extraction procedure, to facilitate an efficient procedure, the plasma protein was precipitated first by using a mixture of a zinc sulfate solution and acetonitrile. Several extraction parameters were carefully evaluated and optimized, including the type and volume of the extraction solvent, salt effect, pH and extraction time. Under the optimum conditions, the limits for quantification were 2.5 and 5.0 ng mL−1 for clevidipine and its primary metabolite, respectively. Sufficient linearity of clevidipine or its primary metabolite was observed with the coefficient of correlation (r) above 0.9979. The method showed good precision and accuracy, with intra- and inter-assay coefficients of variation <6.1% at all concentrations. The proposed pretreatment technique with HPLC was successfully applied to the determinate of clevidipine and its primary metabolite in rat plasma samples. Furthermore, the method, which requires less time than conventional techniques, is environmentally friendly and requires only a small amount of low-toxicity extraction solvent.
研究领域:
药理学
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分析化学
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DOI
PubMed
高影响因子
FOOD CHEMISTRY
·
2023
·
IF 8.8
Di Chen,Xinmiao Bu,Xinli Xu,Bin Wang,Manyu Zhang,Yumei Gan,Hang Yuan,Xu Xia
This study presents an in-pipette-tip kapok fiber-supported liquid extraction/ in-situ derivatization (in-pipette-tip KF-SLE-ISD) method for simultaneous enrichment and derivatization of furfurals . Briefly, 3 mg of natural kapok fiber, which was loaded in an assembled pipette-tip, was used to support 12.5 μL of extractant (ethyl acetate/toluene, 75:25, v/v) containing 10 mM 2,4-dinitrophenylhydrazine. The in-pipette-tip KF-SLE-ISD procedure was conveniently conducted by aspirating/releasing 1 mL of sample solution 10 cycles, allowing simultaneous extraction and derivatization of furfurals. Then, 100 μL of acetonitrile was aspirated/released 5 cycles for elution, 10 μL of which was directly analyzed by high-performance liquid chromatography. The limits of quantitation were in ranges of 0.10–0.45 μg/mL. The method showed satisfied linearity (R 2 > 0.99), precision (RSD < 8.53%) and relative recovery (90.34–114.71%), which was successfully applied to determine furfurals in various samples (e.g., honeys, juices and glucose injections). The proposed method has the merits of effectiveness, simplicity, low cost, wide availability and ease of automation.
研究领域:
分析化学
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食品科学
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产品关联
DOI
PubMed
高影响因子
ANALYTICAL AND BIOANALYTICAL CHEMISTRY
·
2020
·Vol. 413
·期 2
·577-584
·
IF 3.637
Xie Qilong,Xia Ming,Sun Dekui,Cao Jiangping,Xiao Yong,Lin Mingui,Hou Bo,Jia Litao,Li Debao
For simultaneous analysis of four fat-soluble tocopherols (α-, β-, γ-, and δ-) in edible oils, an efficient and green method using deep eutectic solvent-based liquid-phase microextraction (DES-LPME) coupled with reversed-phase high-performance liquid chromatography (RP-HPLC) was developed. The DESs formed by different quaternary ammonium salts and ethanol were used as the extractants. Tetrabutylammonium chloride (TBAC)-ethanol DES at a molar ratio of 1:2 achieved the best extraction efficiency. Under the optimized conditions, the detection limits were in the range of 2.1–3.0 ng mL −1 . The intra-day and inter-day repeatability were in the ranges of 3.9–5.3% and 4.8–7.1%, respectively, and the recoveries for the real samples varied from 80.7% to 105.4%. The developed method was successfully employed for the determination of all four tocopherol homologues with an RP-HPLC system containing a COSMOSIL π-NAP column in five edible oils collected locally.
Graphical abstract
研究领域:
分析化学
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食品科学
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DOI
PubMed
高影响因子
Analytical Methods
·
2024
·Vol. 16
·期 16
·2513-2521
·
IF 2.7
Zhengming Qian,Qinggui Lei,Dan Tang,Guoying Tan,Qi Huang,Fucai Zhou,Wenhao Wang
Sweet tea is a functional herbal tea with anti-inflammatory, anti-diabetic, and other effects, in which phloridzin and trilobatin are two functional compounds. However, the current methods for their quantification are time-consuming, costly, and environmentally unfriendly. In this paper, we propose a rapid method that integrates online pressurized liquid extraction and high-performance liquid chromatography featuring a superficially porous column for fast separation. Moreover, we employ an equal absorption wavelength method to eliminate using multiple standard solutions and relative calibration factors. Our verification process corroborated the technique's selectivity, accuracy, precision, linearity, and detection limitations. Separately, our methodology demonstrated excellent analytical efficiency, cost-effectiveness, and environmental friendliness. Practical application using six distinct batches of sweet tea samples yielded results in congruence with the external standard method. The analytical rate of this technique is up to over 18 times faster than traditional methods, and organic solvent consumption has been reduced to less than 1.5 mL. Therefore, this method provides a valuable way to achieve quality control and green analysis of sweet tea and other herbal teas.
研究领域:
植物化学
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分析化学
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药学
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DOI
PubMed
高影响因子
RSC Advances
·
2016
·Vol. 6
·期 43
·36223-36230
·
IF 3.289
Lu Hu,Wanyu Shan,Ying Zhang,Songqing Li,Haixiang Gao,Runhua Lu,Sanbing Zhang,Wenfeng Zhou
A novel liquid phase microextraction method based on the solidification of floated ionic liquids (SFIL-LPME) was developed to determine four phthalate esters (diethyl phthalate, diallyl phthalate, benzyl butyl phthalate, and dicyclohexyl phthalate) in environmental waters and bottle beverages and subsequently separate them using high-performance liquid chromatography. In this work, we customized a tributyldodecylphosphonium tetrafluoroborate ([P4 4 4 12][BF4]) ionic liquid (IL) to obtain a low density such that it can be solidified at a low temperature, and then used as an extraction solvent in liquid-phase microextraction based on the solidification of floated organic drops (SFO-LPME). This means that more potential ILs can be customized to broaden extraction solvents in SFO-LPME. To identify the significant factors that affect extraction efficiency, parameters such as the volume of [P4 4 4 12][BF4], the extraction time, the rotation speed, the extraction temperature and the ionic strength were optimized using a Plackett–Burman design. A central composite design was then used to optimize the identified significant factors to study the effect of interactions on the experiment. Under these optimized conditions, the extraction recoveries of the four phthalate esters in water samples ranged from 73.0 to 94.6% and in bottled beverage were from 70.2 to 101.3%, with relative standard deviations (RSDs) ranging from 0.6 to 8.2% and 0.6 to 7.8%. Good linearity for both water samples and bottled beverages were obtained in the range of 5–500 μg L−1, with correlation coefficients greater than 0.9993. The limits of detection for the four phthalate esters varied from 0.27 to 1.1 μg L−1 for water samples and 1.22 to 2.36 μg L−1 for bottled beverages. The two developed methods were then successfully applied to the determination of phthalate esters in environmental waters and bottled beverages.
研究领域:
分析化学
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环境科学
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DOI
高影响因子
JOURNAL OF SEPARATION SCIENCE
·
2018
·Vol. 42
·期 2
·574-581
·
IF 2.415
Kaige Zhang,Shuangying Li,Chuang Liu,Qi Wang,Yunhe Wang,Jing Fan
In recent years, hydrophobic deep eutectic solvents as new generation of green solvents have attracted wide attention in liquid microextraction technique. In this article, four hydrophobic deep eutectic solvents composed of trioctylmethylammonium chloride and oleic acid were designed and prepared firstly. Combined with high-performance liquid chromatography, these deep eutectic solvents were used as an extraction solvent in vortex-assisted dispersive liquid–liquid microextraction for the selective enrichment and indirect determination of trace nitrite from real water and biological samples. This method is based on the diazotization-coupling reaction of nitrite with p -nitroaniline and diphenylamine in acidic water, and then the nitrite is quantified indirectly by measuring the obtained azo compounds. Some factors influencing the extraction efficiency, including the reaction and extraction conditions, were investigated. Under the optimized conditions, the method has a linear range of 1–300 μg/L with a correlation coefficient of 0.9924, limit of detection of 0.2 μg/L, limit of quantitation of 1 μg/L, intraday and interday relative standard deviations of 4.0 and 6.0%. This method was successfully applied in determination of nitrite from three environmental water and two biological samples with the recovery in the range of 90.5–115.2%. In addition, these results were well agreement with those obtained by the conventional Griess method.
研究领域:
分析化学
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环境科学
·
生物学
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DOI
PubMed
高影响因子
Analytical Methods
·
2013
·Vol. 5
·期 21
·5983-5989
·
IF 1.855
Wei Yu,Zhongling Liu,Shiqian Gao,Shusen Cui,Xiao Yang,Wei Qiu,Hanqi Zhang,Aimin Yu,Yanfu Huan
An acetonitrile–salt aqueous two-phase extraction system (ATPS) was developed and applied in the extraction of sulfonamides in blood. HPLC and HPLC–MS were applied in the determination of the analytes. 3 mL of blood sample was diluted with 1 mL pure water and 6 mL of acetonitrile and 1 g of K2HPO4 were added to the sample. The mixture was ultrasonically shaken for 5 min. The ATPS was formed. The hemoglobin in blood was gathered together and suspended between the acetonitrile and aqueous phases. The parameters affecting the extraction efficiency, such as type and volume of extraction solvent, type and amount of salt, pH value of sample solution, extraction time and the amount of dissolution solvent were investigated. The limits of detection for sulfamonomethoxine, sulfachlorpyridazine, sulfamethoxazole and sulfafurazole were 4.81, 1.87, 2.73, 2.17 μg L−1, respectively. When the present method was applied in the analysis of blood samples, the recoveries of the analytes ranged from 80.1 to 96.9% and the relative standard deviations were lower than 7.13%.
研究领域:
分析化学
·
医学检验
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DOI
PubMed
高影响因子
JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE
·
2020
·Vol. 100
·期 13
·4840-4848
·
IF 2.614
Tingting He,Tong Zhou,Hao Wan,Quanbin Han,Yaqian Ma,Ting Tan,Yiqun Wan
BACKGROUND Aflatoxins, a kind of carcinogen, have attracted increasing attention due to their toxicity and harmfulness to human health. Traditional methods for aflatoxins analysis usually involve tedious extraction steps with a subsequent derivatization process. Herein, a simple and efficient liquid-phase microextraction method based on deep eutectic solvents (DESs) for direct analysis of aflatoxins was developed. RESULTS Adopting DESs as the extractant, we surprisingly found out that DESs could either achieve good extraction performance or play a similar role to the derivatization agent, achieving an enhancement of fluorescence intensity for direct analysis of aflatoxins by high-performance liquid chromatography combined with fluorescent detection. Under optimal conditions obtained by response surface methodology, the method provided satisfactory linear ranges (0.01–0.75 μg kg −1 for AFB1 and AFG1, 0.003–0.25 μg kg −1 for AFB2 and AFG2) with good determination coefficients ( R 2 > 0.9988), a low detection limit (0.0005–0.003 μg kg −1 ), and good recovery rates (72.05–113.54%). CONCLUSION These results highlighted superiorities of the one-step DES strategy for analysis of aflatoxins in edible oils, providing insights for future development of efficient methods in food analysis. © 2020 Society of Chemical Industry
研究领域:
食品科学
·
分析化学
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF CHROMATOGRAPHY A
·
2009
·
IF 3.756
Yunli Wu,Bin Hu
A simple, selective, sensitive and inexpensive method of hollow fiber-based liquid–liquid–liquid microextraction (HF-LLLME) combined with high performance liquid chromatography (HPLC)-ultraviolet (UV) detection was developed for the determination of four acidic phytohormones (salicylic acid (SA), indole-3-acetic acid (IAA), (±) abscisic acid (ABA) and (±) jasmonic acid (JA)) in natural coconut juice. To the best of our knowledge, this is the first report on the use of liquid phase microextraction (LPME) as a sample pretreatment technique for the simultaneous analysis of several phytohormones. Using phenetole to fill the pores of hollow fiber as the organic phase, 0.1 mol L −1 NaOH solution in the lumen of hollow fiber as the acceptor phase and 1 mol L −1 HCl as the donor phase, a simultaneous preconcentration of four target phytohormones was realized. The acceptor phase was finally withdrawn into the microsyringe and directly injected into HPLC for the separation and quantification of the target phytohormones. The factors affecting the extraction efficiency of four phytohormones by HF-LLLME were optimized with orthogonal design experiment, and the data was analyzed by Statistical Product and Service Solutions (SPSS) software. Under the optimized conditions, the enrichment factors for SA, IAA, ABA and JA were 243, 215, 52 and 48, with the detection limits (S/N = 3) of 4.6, 1.3, 0.9 ng mL −1 and 8.8 μg mL −1 , respectively. The relative standard deviations (RSDs, n = 7) were 7.9, 4.9, 6.8% at 50 ng mL −1 level for SA, IAA, ABA and 8.4% at 500 μg mL −1 for JA, respectively. To evaluate the accuracy of the method, the developed method was applied for the simultaneous analysis of several phytohormones in five natural coconut juice samples, and the recoveries for the spiked samples were in the range of 88.3–119.1%.
研究领域:
分析化学
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植物学
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产品关联
DOI
PubMed
高影响因子
MICROCHIMICA ACTA
·
2013
·Vol. 180
·期 5
·341-346
·
IF 3.434
Hou Fang,Deng Ting,Jiang Xinyu
We have developed a simple and efficient method for dispersive liquid-liquid microextraction of 4-nitrophenol, 2-naphthol and bisphenol A in real water samples. It is making use of solidified floating organic droplets of 1-dodecanol which has low density and a proper melting point. The type and volume of extraction solvent and dispersive solvent, the effect of salts, pH value and extraction time were optimized and resulted in enrichment factors of 84 for 4-nitrophenol, 123 for 2-naphthol, and 97 for bisphenol A. The limits of detection by HPLC are 1.50, 0.10 and 1.02 ng · mL −1 , respectively. Excellent linearity is observed in the concentration range from 10 to 800 ng · mL −1 , with coefficients of correlation ranging from 0.9988 to 0.9999. The relative standard deviations (for n = 5) are from 3.2 to 5.3 %, and relative recoveries for the three phenols in tap, river and spring water range from 85.0 to 105.0 %, 98.3 to 110.0 %, and 98.6 to 109.0 %, respectively.
Chromatograms of river water blank (b) and spiked river water (a, 500 ng ∙ mL −1 ) analyzed with DLLME-SFO-HPLC. Peak identification: (1) p-nitrophenol; (2) 2-naphthol; (3) bisphenol A. Liquid-liquid microextraction method based on solidification of floating organic droplet (DLLME-SFO) has a high enrichment factor (84, 123and 97), acceptable relative recovery (85.0 %–110.0 %), good repeatability (5.27 %, 3.54 % and 3.16 %) and a wide linear range (10–800 ng · mL −1 ) for the determination of p-nitrophenol, 2-naphthol and bisphenol A.
研究领域:
分析化学
·
环境科学
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产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）