To establish an analytical method for determination of four bisphenols (BPA, BPB, BPF, and BPS) and two alkylphenols (4-n-OP, 4-n-NP) in water by ultra performance liquid chromatography- tandem mass spectrometry ...To establish an analytical method for determination of four bisphenols (BPA, BPB, BPF, and BPS) and two alkylphenols (4-n-OP, 4-n-NP) in water by ultra performance liquid chromatography- tandem mass spectrometry (UPLC/MS/MS). The water samples were extracted and condensed with solid-phase extraction (SPE) using C18 cartridges and eluted by acetonitrile. Separation was carried out with Acquity BEH C8 column and detection were performed by UPLC/MS/MS. Quantification was calculated by using the internal standard BPA-d16 and 4-n-NP-d8. The linear correlation coefficients of these compounds in the range of 1.0-100.0μg/L were all over 0.999. The minimum detectable concentrations were 0.75-1.0 ng/L, and the recoveries ranged from 87.0% to 106.9%.展开更多
The harm of the phenolic compounds to environment was discussed in this paper. The progress of international methods for phenolic compounds was reviewed from 1938 to the end of 1995. The references dealt mainly with t...The harm of the phenolic compounds to environment was discussed in this paper. The progress of international methods for phenolic compounds was reviewed from 1938 to the end of 1995. The references dealt mainly with the progress of study on optical determining methods, e.g. visible , UV , derivative , fluorescent , infrared absorptive , atomic absorptive photometries for phenolic compounds in waste water, and application of the above mentioned methods in environmental monitoring.展开更多
Single wall carbon nanotube modified glassy carbon electrode (SWCNT/GCE) was used for flow-injection analysis (FIA) for phenolic compounds (phenol (P), 4-chlorophenol (CP), 2,4-dichlorophenol (DCP), 2,4,6-trichlorphen...Single wall carbon nanotube modified glassy carbon electrode (SWCNT/GCE) was used for flow-injection analysis (FIA) for phenolic compounds (phenol (P), 4-chlorophenol (CP), 2,4-dichlorophenol (DCP), 2,4,6-trichlorphenol (TCP) and pentachlorophenol (PCP)). Experimental variables such as the detection potential, flow rate and pH of the carrier solution, 0.1 M sodium acetate, were optimized. Under these conditions, the designed electrode showed a very good performance for the amperometric measurements, with no need to apply a cleaning or pre-treatment procedure. The operational stability was tested with 20 repetitive injections of each analyte and was found to be good. The analytical performance of the SWCNT/GCE electrode under flow through conditions was tested and was found to be impressive. When it is compared with other enzymatic and non-enzymatic sensors, it shows wider dynamic range for the detection of phenolic compounds with low limits of detection. These results suggest that the method is quite useful for monitoring and analyzing phenols and chlorophenols.展开更多
A simple isocratic HPLC technique has been developed for the quantitative analysis of phenolic acids (PAs) in fruits and vegetables. Nine benzoic and cinnamic acid derivatives were separated in less than 30 min, and t...A simple isocratic HPLC technique has been developed for the quantitative analysis of phenolic acids (PAs) in fruits and vegetables. Nine benzoic and cinnamic acid derivatives were separated in less than 30 min, and the resolution was all more than 1.23. The ranges of linearity for PAs standards were 0.2-100 ng, even up to 600 ng (r = 0.983-1.000) and the detection limits were 0.02-0.24 mg/kg. Samples of fresh vegetables and fruits were extracted with 80% mcthanol and ethyl acetate, then purified with C18 Sep-Pak cartridge and determined by HPLC. This method was applied to the determination of PAs in 7 kinds of fruits and vegetables, i.e., apple, pear, Chinese cabbage, cauliflower, turnip, soybean sprout and white grape wine. The content of the 9 PAs varied widely in the 7 kinds ol'foods studied. The average concentrations ofchlorogenic acid in apple (100.2 mg/kg) and pear (30.8 mg/kg) were quite high, and sinapinic acid was remarkable (42.5 mg/kg) in Chinese cabbage, and protocatechuic acid had the highest concentration of all the PAs in white wine.展开更多
2,4,6-trichlorophenol molecularly imprinted suspension polymer has been prepared and applied to the molecularly imprinted micro-solid-phase extraction procedure for selective preconcentration of phenolic compounds fro...2,4,6-trichlorophenol molecularly imprinted suspension polymer has been prepared and applied to the molecularly imprinted micro-solid-phase extraction procedure for selective preconcentration of phenolic compounds from environmental water samples. The influence of functional monomer, cross-linker, polymerization condition, porogen, and the ratio of template molecule and functional monomer to cross-linker on the size of the obtained particles were investigated. It was found that methyacrylic acid as functional monomer, divinylbenzene as cross-linker, the molar ratio of template molecule and functional monomer to cross-linker was 1:4:20, the amount of AIBN was 100 mg, ultraviolet radiation at 365 nm were the optimal conditions, and at these conditions, the polymers had the best adsorption efficiency and had the monodispersity of 2 - 3 μm microsphere particles. The characteristics of the MIMSPE method were valid by high performance liquid chromatography. This MIMSPE-HPLC method has been successfully applied to the direct preconcentration and determination of phenolic compounds (phenol, 4-chlorophenol, 2,4-dichlorophenol, 2,4,6-trichlorophenol, pentachlorophenol) in environmental water samples.展开更多
A single-drop liquid phase micro-extraction procedure using 1-butyl-3-methylimidazolium hexafluorophosphate ([C4MIM][PF6]) was demonstrated for the sensitive determination of four phenols in water samples. Under the...A single-drop liquid phase micro-extraction procedure using 1-butyl-3-methylimidazolium hexafluorophosphate ([C4MIM][PF6]) was demonstrated for the sensitive determination of four phenols in water samples. Under the optimized conditions, the linear range of proposed method was excellent in the range of 0.5-100 μg·L^-1, the reproducibility (RSD, n=6) were in the range 5.4%-8.9% and detection limits (S/N=3) were 0.3, 0.3, 0.5 and 0.5 μg·L^-1 for 2, 4-dichlorophenol, 2-naphthol, 2-nitrophenol and 4-chlorophenol, respectively. The experimental results indicated that the effect of complex matrices natural water samples could be resolved with addition of sodium ethylene diamine tetracetate (EDTA) into the samples. Excellent spiked recoveries were achieved for these four phenols ranged from 86.2%-114.9 %. All these facts demonstrated that the proposed method with merits of low cost, simplicity and easy operating would be a competitive alternative procedure for the determination of such compounds at trace level.展开更多
Folin Ciocalteu (F-C) assay is the most widely used and convenient method to determine the total phenolics content in foods, herbs, and other plant extracts. Different phenolics standards such as gallic acid, ferulic ...Folin Ciocalteu (F-C) assay is the most widely used and convenient method to determine the total phenolics content in foods, herbs, and other plant extracts. Different phenolics standards such as gallic acid, ferulic acid, chlorogenic acid, catechol, and vanillic acid have been used for calibration curves in this assay method. Comparison of these standards, in single or combination of two or more, for more accurate determination of phenolics has not been reported so far. This study tested five single phenolics and seven combinations of mixed phenolic standards to evaluate the optimal standards for F-C method. The different standards were tested to calculate the phenolic content in three known test solutions. We also evaluated interference effect of various compounds in phenolics estimation by F-C method that is usually present in the lignocellulosic biomass-derived sugar solution, and in food products along with phenolics. Finally, the optimal standards with five phenolics were used for the determination of phenolics in alkali pretreated biomass extract. The results indicated that gallic acid was the best standard among the single phenolic compounds and five phenolic compounds solution was the best standard among the mixed phenolic solutions. The presence of glucose, HMF, furfural, and vitamin-B12 did not interfere in phenolic determination;whereas ascorbic acid, tyrosine, formic acid, and acetic acid strongly interfered the results. The results also showed that biomass pelleting process did not affect the generation of phenolics in alkali pretreatment extract.展开更多
This study aimed in the identification and quantification of phenolic compounds in different four varieties of rapeseeds (Brassica napus L.) using LC-MS and HPLC. LC-MS analysis guided to identify 12 phenolic compound...This study aimed in the identification and quantification of phenolic compounds in different four varieties of rapeseeds (Brassica napus L.) using LC-MS and HPLC. LC-MS analysis guided to identify 12 phenolic compounds including sinapine, sinapine(4-O-8')guaiacyl, feruloyl choline(4-O-8') guaiacyl, kaempferol-3-O-sinapoyl-sophoroside-7-O-glucoside, kaempferol-3-O-β-sophoroside, cyclic spermidine-alkaloid, feruloyl choline(5-8')guaiacyl, kaempferol-sinapoyl-trihexoside,1,2-di- O-sinapoyl-gentiobiose, 1,2-di-O-sinapoyl-glucose, feruloyl choline(4-O-8')guaiacyl-di-sinapoyl, and sinapine(4-O-8')guaiacyl-di-sinapoyl, respectively. Total phenolic compounds in rapeseed meals were ranged from 38.50 (2012 “Sunmang”) to 63.95 mg/g dry weight (DW) (2014 Jeju local cultivar). Main phenolic compositions were cyclic spermidine-alkaloid, kaempferol, feruloyl choline, and sinapine. Sinapine was predominant compound among all the samples ranged from 29.74 to 52.24 mg/g DW (mean 79% of total phenolic contents). This study provided the information for the variation of phenolic compounds between the varieties of rapeseeds and the cultivation periods. Furthermore, this information can be developed for bio-energy industry as a reducer of the cost of the bio-energy products.展开更多
A rapid, simple and sensitive method was demonstrated for the determination of phenolic compounds in water samples by alternating-current oscillopolarographic titration. With the presence of sulfuric acid, phenol coul...A rapid, simple and sensitive method was demonstrated for the determination of phenolic compounds in water samples by alternating-current oscillopolarographic titration. With the presence of sulfuric acid, phenol could be transferred into a nitroso-compound by reacting with NaNO2. The titration end-point was obtained by the formation of a sharp cut in the oscillopolarographic with infinitesimal NaNO2 on double platinum electrodes. The results showed that phenol had an excellent linear relationship over the range of 4.82×10^-6 -9.65×10^-3 mol/L, the RSD of the proposed method was lower than 1.5%, and the spiked recoveries of three real water samples were in the range of 95.6%-106.9%.展开更多
Total anthocyanins of spices (Syzygium aromaticum L., Coriadrum sativum L., Cuminum cyminum L., Zingiber officinale Rosc., Elettaria cardamomum, Curcuma longa, Rhus coriaria L., Cinnamomum zeylanicum Blume, Foeniculum...Total anthocyanins of spices (Syzygium aromaticum L., Coriadrum sativum L., Cuminum cyminum L., Zingiber officinale Rosc., Elettaria cardamomum, Curcuma longa, Rhus coriaria L., Cinnamomum zeylanicum Blume, Foeniculum vulgare Mill and Laurus nobilis L.) were determined using acidified (1% HCl) solvents (methanol, ethanol and acetone) at three temperatures (20℃, 40℃ and 60℃). Also phenolic acids were separated and identified by RP-HPLC. Results showed that sumac and cinnamon had the highest levels of anthocyanins, while for the acetone the cinnamon indicated the highest amount of anthocyanins when methanol and ethanol were used as extracting solvents at 20℃. At 40℃ using ethanol, sumac showed the highest level of anthocyanins whereas acetone solvent yielded the highest anthocyanin contents for cinnamon. At 60℃, cinnamon showed the highest level of anthocyanins when methanol and acetone were the solvents, while sumac had the highest anthocyanins level using ethanol as solvent. HPLC results showed ten phenolic acids found in those spices and varied in their concentrations. Gallic acid had the highest level (1642.3 mg/100g) (cloves). Gentisic acid had the lowest level (1.2 mg/100g) in ginger. Also sumac showed the highest level of chlorogenic acid (1528.7 mg/100g). Some acids were not found in some spices, for instance, benzoic acid was not found in coriander, cumin, ginger, green cardamom, cinnamon and sweet laurel.展开更多
During the Folin Ciocalteu (F-C) micro-assay for the determination of phenolics in the presence of methanol, fine solids can form. In a previous paper, we hypothesized that the interference from alcohol on the F-C rea...During the Folin Ciocalteu (F-C) micro-assay for the determination of phenolics in the presence of methanol, fine solids can form. In a previous paper, we hypothesized that the interference from alcohol on the F-C reaction can be minimized depending on the particular procedure used to reach the alkalinity condition. In order to demonstrate our hypothesis we studied, by spectrophotometrically monitoring, the time-behaviour of the reactions carried out in the presence of different methanol concentrations at the same alkalinity condition from two protocols. The results showed that the interfering effect of methanol on the F-C micro-method can be affect and even prevented depending on working conditions. In particular, the formation of fine solids can be delayed, slowed down and prevented depending on the initial carbonate concentration used. We have explained why the initial carbonate concentration, used to reach the final alkalinity condition, plays an important role in the F-C reaction carried out in the presence of methanol. Moreover, the results from real-time monitoring showed that, differently from traditional F-C procedure, our procedure allows us to carry out the F-C micro method in the presence of 6% methanol, as an extreme concentration, reading the absorbance at real time 24 min. The real-time monitoring of absorbance can be considered as a useful means to explore the effect of other parameters on precipitate formation caused by the presence of methanol in the F-C reaction.展开更多
Phenolic compounds have become one kind of the important pollutants of the marine environment. Single-walled Carbon nanotubes, as one-dimensional nano materials, have light weight and perfect hexagonal structure of co...Phenolic compounds have become one kind of the important pollutants of the marine environment. Single-walled Carbon nanotubes, as one-dimensional nano materials, have light weight and perfect hexagonal structure of connections, with many unusual mechanical, chemical and electrical properties. In recent years, with the research of carbon nanotubes and other nano materials, the application prospect is also constantly discussed. In this paper, homemade single-walled carbon nanotubes(SWCNTs) coating was used for establishing an analytical approach to the determination of five kinds of phenolic compounds in seawater using SPME-GC-MS. Optimal conditions: After saturation was conducted with Na Cl, and p H was adjusted to 2.0 with H_2SO_4, the extract was immersed in a water bath at 40 for GC℃-MS determination through 40-min agitating extraction at 500 rmin^(-1) and 3-min desorption at 280℃. The liniearities ranged between 0.01-100 μg L^(-1), and the determination limits ranged between 1.5-10 ngL^(-1). The relative standard deviation(RSD, n = 5) was less than 6.5%. For the phenolic compounds obtained from the spiked recovery test for actual seawater samples, the rates of recovery were 87.5%-101.7%, and the RSDs were less than 8.8%, which met the requirements of determination. Due to its simplicity, high efficiency and low consumption, this approach is suitable for the analysis of trace amounts of phenolic compounds in marine waters.展开更多
[Objectives] To study on colorimetric method and content determination of total phenol in homemade plum wine. [Methods]The optimal determination condition of total polyphenols content in plum wine( commercially availa...[Objectives] To study on colorimetric method and content determination of total phenol in homemade plum wine. [Methods]The optimal determination condition of total polyphenols content in plum wine( commercially available and homemade) by Folin-Ciocalteu method was inspected,and commercially available and homemade plum wine was evaluated by the method. [Results]The optimal determination conditions of total polyphenols content: sample dose of 1. 0 m L,Folin-Ciocalteu reagent of 1 m L,4% Na_2CO_3 solution of 4. 0 m L,reaction temperature of 50 ℃,reaction time of 1. 5 h,and determination wavelength of 756 nm. Absorbance showed good linear relationship with total polyphenols content within the range of 17. 73-59. 12 μg/m L( y = 14. 878 x + 0. 0739,R^2= 0. 9998). Recovery rate of adding standard sample was between 98. 8% and 103. 5%,and relative standard deviation was 2. 0%( n = 5). [Conclusions]The method had high precision degree and good stability,which was suitable for measuring total polyphenols content in plum wine( commercially available and homemade).展开更多
The product of the reaction among phenol, sodium nitroprusside and hydroxylamine hydrochloride in an alkaline solution can be extracted by chloroform in the presence of cetylpyridinium bromide(CPB), on the basis of ...The product of the reaction among phenol, sodium nitroprusside and hydroxylamine hydrochloride in an alkaline solution can be extracted by chloroform in the presence of cetylpyridinium bromide(CPB), on the basis of which a new extraction spectrophotometric method for the determination of phenol in water is developed. The optimum determination wavelength is 720 nm. The molar absorptivity is 1. 05 × 10~5 mol^(-1)· L· cm^(-1) and the detection limit is 4. 0 μg/L. For 30. 0 and 60. 0 μg/L standard solutions, the relative standard deviations are 4. 5% and 2.2 %, respectively(n=6). F values of the statistical analysis show that there is no notable difference between the proposed method and 4-AAP method. The results of the standard addition method for the natural water samples are satisfactory.展开更多
[Objectives]This study aimed to establish a QAMS(quantitative analysis of multi-components by single-marker)method for simultaneous determination of four phenolic acids,salvianolic acid B,tanshinol,lithospermic acid a...[Objectives]This study aimed to establish a QAMS(quantitative analysis of multi-components by single-marker)method for simultaneous determination of four phenolic acids,salvianolic acid B,tanshinol,lithospermic acid and rosmarinic acid in Radix Salviae Miltiorrhizae by HPLC and conduct methodological investigation.[Methods]Salvianolic acid B,with moderate retention time,good resolution,great response value and easy availability was selected as the internal standard,and the relative retention values and relative correction factors between tanshinol,rosmarinic acid,lithospermic acid and salvianolic acid B were established.The results of QAMS were compared with those of external standard method to verify the accuracy and applicability of QAMS.[Results]There were no significant differences between the calculated values of QAMS and the measured values of external standard method.The relative deviation was less than 3%,and the relative correction factors obtained from the experiment were credible.[Conclusions]QAMS can be used to determine the contents of phenolic acids in Radix Salviae Miltiorrhizae formula granules.展开更多
Reproduction via cis-binary mechanisms appears to have evolved fairly early in the evolution of complex organisms, and a system committed to prior to evolution of humans. While the evolution of a chromosomal-specific ...Reproduction via cis-binary mechanisms appears to have evolved fairly early in the evolution of complex organisms, and a system committed to prior to evolution of humans. While the evolution of a chromosomal-specific approach has been a successful strategy for survival of a large variety of species including humans, the fidelity of sex determination leading to 100% cis-binary outcomes is not achieved in many species, with evidence for homosexual or bisexual behaviour evident in more than 1500 species. Thus, such outcomes indicates that sex determination is a multi-step process and not a single event, and as such, could lead to the appearance of variants during the process which developed much earlier than humans. Variants could arise either due to intrinsic variation in the steps of determination, or also be influenced by environmental factors of a biological or psychological nature. In contrast to homosexual variants which do not require interventions such as hormone therapy or surgery, expression of gender dysphoria, is more based in psychology, but also has biological underpinnings and can be influenced by such hormonal interventions and surgery. While the numbers of those with gender dysphoria is small (~0.6% - 1.0% of population), the attention given to this issue raises the possibility of biological and psychological environmental factors impacting the emergence of some of those expressing gender dysphoria. Furthermore, transitioning from male-to-female or female-to-male can have consequences regarding disease risks latter in life, including the appearance of autoimmune diseases. This review will attempt to review some of the evidence regarding sex determination, discuss why the system has potentially not been improved upon during evolution, how a potential role for sex chromosome function on neurodevelopment may be central to variation in humans, and how commitment to the current strategy is likely integrated into other sex-related events such as puberty, pregnancy, and menopause to ensure species survival. It will also discuss how variants in sex determination could contribute to sex differences in disease risk and how epigenetic modifications could play a role in such risk. .展开更多
[Objectives] To determine the optimum extraction technology for total phenols of leaves in Acanthopanax giraldii Harms.[Methods]The single factor test and orthogonal design were adopted to study the extraction technol...[Objectives] To determine the optimum extraction technology for total phenols of leaves in Acanthopanax giraldii Harms.[Methods]The single factor test and orthogonal design were adopted to study the extraction technology for total phenols of leaves in Acanthopanax giraldii Harms. [Results]The optimum extraction conditions were determined as follows: extraction solvent( 70% methanol),solid-liquid ratio( 1∶ 35),and reflux extraction time( 60 min). Under these conditions,the yield of crude extract from total phenols of leaves in Acanthopanax giraldii Harms was 38. 67 mg/g.[Conclusions] The technology was simple,and of low cost and high extraction rate,suitable for the extraction of total phenols of leaves in Acanthopanax giraldii Harms.展开更多
Sulfuric acid-phenol and sulfuric acid-anthrone methods were used to detect polysaccharide content in shoots of Aralia elata( Miq.) Seem.,and the conversion factor to glucose was measured with refined polysaccharide...Sulfuric acid-phenol and sulfuric acid-anthrone methods were used to detect polysaccharide content in shoots of Aralia elata( Miq.) Seem.,and the conversion factor to glucose was measured with refined polysaccharides. Comprehensive evaluation was carried out by linear relationship,precision,reproducibility,stability and recovery rate. The results showed that the linear relationship between glucose concentration and absorbance was good when glucose concentration was0-40 μg/ml,and the average recovery rate was equal to or higher than 97. 00% with good reproducibility( RSD 〈 1. 60%,n = 5). It revealed that the two methods were accurate and reliable,and suitable for the determination of polysaccharide content in the shoots of A. elata. Polysaccharide content detected by sulfuric acid-phenol and sulfuric acid-anthrone methods was 19. 31% and 20. 40% respectively.展开更多
基金supported by the Preventive medicine and public health research project of Anhui,China(No.2011Y0103)the Natural Science Foundation of Anhui,China(No.11040606M216)
文摘To establish an analytical method for determination of four bisphenols (BPA, BPB, BPF, and BPS) and two alkylphenols (4-n-OP, 4-n-NP) in water by ultra performance liquid chromatography- tandem mass spectrometry (UPLC/MS/MS). The water samples were extracted and condensed with solid-phase extraction (SPE) using C18 cartridges and eluted by acetonitrile. Separation was carried out with Acquity BEH C8 column and detection were performed by UPLC/MS/MS. Quantification was calculated by using the internal standard BPA-d16 and 4-n-NP-d8. The linear correlation coefficients of these compounds in the range of 1.0-100.0μg/L were all over 0.999. The minimum detectable concentrations were 0.75-1.0 ng/L, and the recoveries ranged from 87.0% to 106.9%.
文摘The harm of the phenolic compounds to environment was discussed in this paper. The progress of international methods for phenolic compounds was reviewed from 1938 to the end of 1995. The references dealt mainly with the progress of study on optical determining methods, e.g. visible , UV , derivative , fluorescent , infrared absorptive , atomic absorptive photometries for phenolic compounds in waste water, and application of the above mentioned methods in environmental monitoring.
文摘Single wall carbon nanotube modified glassy carbon electrode (SWCNT/GCE) was used for flow-injection analysis (FIA) for phenolic compounds (phenol (P), 4-chlorophenol (CP), 2,4-dichlorophenol (DCP), 2,4,6-trichlorphenol (TCP) and pentachlorophenol (PCP)). Experimental variables such as the detection potential, flow rate and pH of the carrier solution, 0.1 M sodium acetate, were optimized. Under these conditions, the designed electrode showed a very good performance for the amperometric measurements, with no need to apply a cleaning or pre-treatment procedure. The operational stability was tested with 20 repetitive injections of each analyte and was found to be good. The analytical performance of the SWCNT/GCE electrode under flow through conditions was tested and was found to be impressive. When it is compared with other enzymatic and non-enzymatic sensors, it shows wider dynamic range for the detection of phenolic compounds with low limits of detection. These results suggest that the method is quite useful for monitoring and analyzing phenols and chlorophenols.
文摘A simple isocratic HPLC technique has been developed for the quantitative analysis of phenolic acids (PAs) in fruits and vegetables. Nine benzoic and cinnamic acid derivatives were separated in less than 30 min, and the resolution was all more than 1.23. The ranges of linearity for PAs standards were 0.2-100 ng, even up to 600 ng (r = 0.983-1.000) and the detection limits were 0.02-0.24 mg/kg. Samples of fresh vegetables and fruits were extracted with 80% mcthanol and ethyl acetate, then purified with C18 Sep-Pak cartridge and determined by HPLC. This method was applied to the determination of PAs in 7 kinds of fruits and vegetables, i.e., apple, pear, Chinese cabbage, cauliflower, turnip, soybean sprout and white grape wine. The content of the 9 PAs varied widely in the 7 kinds ol'foods studied. The average concentrations ofchlorogenic acid in apple (100.2 mg/kg) and pear (30.8 mg/kg) were quite high, and sinapinic acid was remarkable (42.5 mg/kg) in Chinese cabbage, and protocatechuic acid had the highest concentration of all the PAs in white wine.
文摘2,4,6-trichlorophenol molecularly imprinted suspension polymer has been prepared and applied to the molecularly imprinted micro-solid-phase extraction procedure for selective preconcentration of phenolic compounds from environmental water samples. The influence of functional monomer, cross-linker, polymerization condition, porogen, and the ratio of template molecule and functional monomer to cross-linker on the size of the obtained particles were investigated. It was found that methyacrylic acid as functional monomer, divinylbenzene as cross-linker, the molar ratio of template molecule and functional monomer to cross-linker was 1:4:20, the amount of AIBN was 100 mg, ultraviolet radiation at 365 nm were the optimal conditions, and at these conditions, the polymers had the best adsorption efficiency and had the monodispersity of 2 - 3 μm microsphere particles. The characteristics of the MIMSPE method were valid by high performance liquid chromatography. This MIMSPE-HPLC method has been successfully applied to the direct preconcentration and determination of phenolic compounds (phenol, 4-chlorophenol, 2,4-dichlorophenol, 2,4,6-trichlorophenol, pentachlorophenol) in environmental water samples.
文摘A single-drop liquid phase micro-extraction procedure using 1-butyl-3-methylimidazolium hexafluorophosphate ([C4MIM][PF6]) was demonstrated for the sensitive determination of four phenols in water samples. Under the optimized conditions, the linear range of proposed method was excellent in the range of 0.5-100 μg·L^-1, the reproducibility (RSD, n=6) were in the range 5.4%-8.9% and detection limits (S/N=3) were 0.3, 0.3, 0.5 and 0.5 μg·L^-1 for 2, 4-dichlorophenol, 2-naphthol, 2-nitrophenol and 4-chlorophenol, respectively. The experimental results indicated that the effect of complex matrices natural water samples could be resolved with addition of sodium ethylene diamine tetracetate (EDTA) into the samples. Excellent spiked recoveries were achieved for these four phenols ranged from 86.2%-114.9 %. All these facts demonstrated that the proposed method with merits of low cost, simplicity and easy operating would be a competitive alternative procedure for the determination of such compounds at trace level.
文摘Folin Ciocalteu (F-C) assay is the most widely used and convenient method to determine the total phenolics content in foods, herbs, and other plant extracts. Different phenolics standards such as gallic acid, ferulic acid, chlorogenic acid, catechol, and vanillic acid have been used for calibration curves in this assay method. Comparison of these standards, in single or combination of two or more, for more accurate determination of phenolics has not been reported so far. This study tested five single phenolics and seven combinations of mixed phenolic standards to evaluate the optimal standards for F-C method. The different standards were tested to calculate the phenolic content in three known test solutions. We also evaluated interference effect of various compounds in phenolics estimation by F-C method that is usually present in the lignocellulosic biomass-derived sugar solution, and in food products along with phenolics. Finally, the optimal standards with five phenolics were used for the determination of phenolics in alkali pretreated biomass extract. The results indicated that gallic acid was the best standard among the single phenolic compounds and five phenolic compounds solution was the best standard among the mixed phenolic solutions. The presence of glucose, HMF, furfural, and vitamin-B12 did not interfere in phenolic determination;whereas ascorbic acid, tyrosine, formic acid, and acetic acid strongly interfered the results. The results also showed that biomass pelleting process did not affect the generation of phenolics in alkali pretreatment extract.
文摘This study aimed in the identification and quantification of phenolic compounds in different four varieties of rapeseeds (Brassica napus L.) using LC-MS and HPLC. LC-MS analysis guided to identify 12 phenolic compounds including sinapine, sinapine(4-O-8')guaiacyl, feruloyl choline(4-O-8') guaiacyl, kaempferol-3-O-sinapoyl-sophoroside-7-O-glucoside, kaempferol-3-O-β-sophoroside, cyclic spermidine-alkaloid, feruloyl choline(5-8')guaiacyl, kaempferol-sinapoyl-trihexoside,1,2-di- O-sinapoyl-gentiobiose, 1,2-di-O-sinapoyl-glucose, feruloyl choline(4-O-8')guaiacyl-di-sinapoyl, and sinapine(4-O-8')guaiacyl-di-sinapoyl, respectively. Total phenolic compounds in rapeseed meals were ranged from 38.50 (2012 “Sunmang”) to 63.95 mg/g dry weight (DW) (2014 Jeju local cultivar). Main phenolic compositions were cyclic spermidine-alkaloid, kaempferol, feruloyl choline, and sinapine. Sinapine was predominant compound among all the samples ranged from 29.74 to 52.24 mg/g DW (mean 79% of total phenolic contents). This study provided the information for the variation of phenolic compounds between the varieties of rapeseeds and the cultivation periods. Furthermore, this information can be developed for bio-energy industry as a reducer of the cost of the bio-energy products.
基金Project supported by the Creative Talented Person's Fund of Henan Province (High Teaching [2005]-126)the Natural Science Foundation of Henan Province (No. 0511053000)+1 种基金the Youth Science Foundation of Henan Normal University (No. 2004005)the Henan Key Laboratory for Environmental Pollution Control.
文摘A rapid, simple and sensitive method was demonstrated for the determination of phenolic compounds in water samples by alternating-current oscillopolarographic titration. With the presence of sulfuric acid, phenol could be transferred into a nitroso-compound by reacting with NaNO2. The titration end-point was obtained by the formation of a sharp cut in the oscillopolarographic with infinitesimal NaNO2 on double platinum electrodes. The results showed that phenol had an excellent linear relationship over the range of 4.82×10^-6 -9.65×10^-3 mol/L, the RSD of the proposed method was lower than 1.5%, and the spiked recoveries of three real water samples were in the range of 95.6%-106.9%.
文摘Total anthocyanins of spices (Syzygium aromaticum L., Coriadrum sativum L., Cuminum cyminum L., Zingiber officinale Rosc., Elettaria cardamomum, Curcuma longa, Rhus coriaria L., Cinnamomum zeylanicum Blume, Foeniculum vulgare Mill and Laurus nobilis L.) were determined using acidified (1% HCl) solvents (methanol, ethanol and acetone) at three temperatures (20℃, 40℃ and 60℃). Also phenolic acids were separated and identified by RP-HPLC. Results showed that sumac and cinnamon had the highest levels of anthocyanins, while for the acetone the cinnamon indicated the highest amount of anthocyanins when methanol and ethanol were used as extracting solvents at 20℃. At 40℃ using ethanol, sumac showed the highest level of anthocyanins whereas acetone solvent yielded the highest anthocyanin contents for cinnamon. At 60℃, cinnamon showed the highest level of anthocyanins when methanol and acetone were the solvents, while sumac had the highest anthocyanins level using ethanol as solvent. HPLC results showed ten phenolic acids found in those spices and varied in their concentrations. Gallic acid had the highest level (1642.3 mg/100g) (cloves). Gentisic acid had the lowest level (1.2 mg/100g) in ginger. Also sumac showed the highest level of chlorogenic acid (1528.7 mg/100g). Some acids were not found in some spices, for instance, benzoic acid was not found in coriander, cumin, ginger, green cardamom, cinnamon and sweet laurel.
文摘During the Folin Ciocalteu (F-C) micro-assay for the determination of phenolics in the presence of methanol, fine solids can form. In a previous paper, we hypothesized that the interference from alcohol on the F-C reaction can be minimized depending on the particular procedure used to reach the alkalinity condition. In order to demonstrate our hypothesis we studied, by spectrophotometrically monitoring, the time-behaviour of the reactions carried out in the presence of different methanol concentrations at the same alkalinity condition from two protocols. The results showed that the interfering effect of methanol on the F-C micro-method can be affect and even prevented depending on working conditions. In particular, the formation of fine solids can be delayed, slowed down and prevented depending on the initial carbonate concentration used. We have explained why the initial carbonate concentration, used to reach the final alkalinity condition, plays an important role in the F-C reaction carried out in the presence of methanol. Moreover, the results from real-time monitoring showed that, differently from traditional F-C procedure, our procedure allows us to carry out the F-C micro method in the presence of 6% methanol, as an extreme concentration, reading the absorbance at real time 24 min. The real-time monitoring of absorbance can be considered as a useful means to explore the effect of other parameters on precipitate formation caused by the presence of methanol in the F-C reaction.
基金supported by the Fund project: Marine Project Special Public Welfare Industry Scientific Research Funds (201405037)
文摘Phenolic compounds have become one kind of the important pollutants of the marine environment. Single-walled Carbon nanotubes, as one-dimensional nano materials, have light weight and perfect hexagonal structure of connections, with many unusual mechanical, chemical and electrical properties. In recent years, with the research of carbon nanotubes and other nano materials, the application prospect is also constantly discussed. In this paper, homemade single-walled carbon nanotubes(SWCNTs) coating was used for establishing an analytical approach to the determination of five kinds of phenolic compounds in seawater using SPME-GC-MS. Optimal conditions: After saturation was conducted with Na Cl, and p H was adjusted to 2.0 with H_2SO_4, the extract was immersed in a water bath at 40 for GC℃-MS determination through 40-min agitating extraction at 500 rmin^(-1) and 3-min desorption at 280℃. The liniearities ranged between 0.01-100 μg L^(-1), and the determination limits ranged between 1.5-10 ngL^(-1). The relative standard deviation(RSD, n = 5) was less than 6.5%. For the phenolic compounds obtained from the spiked recovery test for actual seawater samples, the rates of recovery were 87.5%-101.7%, and the RSDs were less than 8.8%, which met the requirements of determination. Due to its simplicity, high efficiency and low consumption, this approach is suitable for the analysis of trace amounts of phenolic compounds in marine waters.
基金Supported by Sichuan Science and Technology Support Plan(2015FZ0026)Postgraduate Innovation Project of Southwest University for Nationalities(CX2016SZ016)
文摘[Objectives] To study on colorimetric method and content determination of total phenol in homemade plum wine. [Methods]The optimal determination condition of total polyphenols content in plum wine( commercially available and homemade) by Folin-Ciocalteu method was inspected,and commercially available and homemade plum wine was evaluated by the method. [Results]The optimal determination conditions of total polyphenols content: sample dose of 1. 0 m L,Folin-Ciocalteu reagent of 1 m L,4% Na_2CO_3 solution of 4. 0 m L,reaction temperature of 50 ℃,reaction time of 1. 5 h,and determination wavelength of 756 nm. Absorbance showed good linear relationship with total polyphenols content within the range of 17. 73-59. 12 μg/m L( y = 14. 878 x + 0. 0739,R^2= 0. 9998). Recovery rate of adding standard sample was between 98. 8% and 103. 5%,and relative standard deviation was 2. 0%( n = 5). [Conclusions]The method had high precision degree and good stability,which was suitable for measuring total polyphenols content in plum wine( commercially available and homemade).
文摘The product of the reaction among phenol, sodium nitroprusside and hydroxylamine hydrochloride in an alkaline solution can be extracted by chloroform in the presence of cetylpyridinium bromide(CPB), on the basis of which a new extraction spectrophotometric method for the determination of phenol in water is developed. The optimum determination wavelength is 720 nm. The molar absorptivity is 1. 05 × 10~5 mol^(-1)· L· cm^(-1) and the detection limit is 4. 0 μg/L. For 30. 0 and 60. 0 μg/L standard solutions, the relative standard deviations are 4. 5% and 2.2 %, respectively(n=6). F values of the statistical analysis show that there is no notable difference between the proposed method and 4-AAP method. The results of the standard addition method for the natural water samples are satisfactory.
基金Supported by High-level Entrepreneurial and Innovative Talent(Team)Project 2015.
文摘[Objectives]This study aimed to establish a QAMS(quantitative analysis of multi-components by single-marker)method for simultaneous determination of four phenolic acids,salvianolic acid B,tanshinol,lithospermic acid and rosmarinic acid in Radix Salviae Miltiorrhizae by HPLC and conduct methodological investigation.[Methods]Salvianolic acid B,with moderate retention time,good resolution,great response value and easy availability was selected as the internal standard,and the relative retention values and relative correction factors between tanshinol,rosmarinic acid,lithospermic acid and salvianolic acid B were established.The results of QAMS were compared with those of external standard method to verify the accuracy and applicability of QAMS.[Results]There were no significant differences between the calculated values of QAMS and the measured values of external standard method.The relative deviation was less than 3%,and the relative correction factors obtained from the experiment were credible.[Conclusions]QAMS can be used to determine the contents of phenolic acids in Radix Salviae Miltiorrhizae formula granules.
文摘Reproduction via cis-binary mechanisms appears to have evolved fairly early in the evolution of complex organisms, and a system committed to prior to evolution of humans. While the evolution of a chromosomal-specific approach has been a successful strategy for survival of a large variety of species including humans, the fidelity of sex determination leading to 100% cis-binary outcomes is not achieved in many species, with evidence for homosexual or bisexual behaviour evident in more than 1500 species. Thus, such outcomes indicates that sex determination is a multi-step process and not a single event, and as such, could lead to the appearance of variants during the process which developed much earlier than humans. Variants could arise either due to intrinsic variation in the steps of determination, or also be influenced by environmental factors of a biological or psychological nature. In contrast to homosexual variants which do not require interventions such as hormone therapy or surgery, expression of gender dysphoria, is more based in psychology, but also has biological underpinnings and can be influenced by such hormonal interventions and surgery. While the numbers of those with gender dysphoria is small (~0.6% - 1.0% of population), the attention given to this issue raises the possibility of biological and psychological environmental factors impacting the emergence of some of those expressing gender dysphoria. Furthermore, transitioning from male-to-female or female-to-male can have consequences regarding disease risks latter in life, including the appearance of autoimmune diseases. This review will attempt to review some of the evidence regarding sex determination, discuss why the system has potentially not been improved upon during evolution, how a potential role for sex chromosome function on neurodevelopment may be central to variation in humans, and how commitment to the current strategy is likely integrated into other sex-related events such as puberty, pregnancy, and menopause to ensure species survival. It will also discuss how variants in sex determination could contribute to sex differences in disease risk and how epigenetic modifications could play a role in such risk. .
基金Supported by Sichuan Science and Technology Support Program(2015SZ-0034)Innovative Research Project for 2016 Graduate in Southwest University for Nationalities(CX2016SZ013)
文摘[Objectives] To determine the optimum extraction technology for total phenols of leaves in Acanthopanax giraldii Harms.[Methods]The single factor test and orthogonal design were adopted to study the extraction technology for total phenols of leaves in Acanthopanax giraldii Harms. [Results]The optimum extraction conditions were determined as follows: extraction solvent( 70% methanol),solid-liquid ratio( 1∶ 35),and reflux extraction time( 60 min). Under these conditions,the yield of crude extract from total phenols of leaves in Acanthopanax giraldii Harms was 38. 67 mg/g.[Conclusions] The technology was simple,and of low cost and high extraction rate,suitable for the extraction of total phenols of leaves in Acanthopanax giraldii Harms.
基金Supported by Scientific Research Project of Education Department of Liaoning Province,China(L2017lkyfwdf-05)Public Welfare Fund Project of Department of Science and Technology of Liaoning Province,China(2016003003)
文摘Sulfuric acid-phenol and sulfuric acid-anthrone methods were used to detect polysaccharide content in shoots of Aralia elata( Miq.) Seem.,and the conversion factor to glucose was measured with refined polysaccharides. Comprehensive evaluation was carried out by linear relationship,precision,reproducibility,stability and recovery rate. The results showed that the linear relationship between glucose concentration and absorbance was good when glucose concentration was0-40 μg/ml,and the average recovery rate was equal to or higher than 97. 00% with good reproducibility( RSD 〈 1. 60%,n = 5). It revealed that the two methods were accurate and reliable,and suitable for the determination of polysaccharide content in the shoots of A. elata. Polysaccharide content detected by sulfuric acid-phenol and sulfuric acid-anthrone methods was 19. 31% and 20. 40% respectively.