Table of Content

22 November 2021, Volume 51 Issue 11 Previous Issue    Next Issue

Basic research

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Synthesis and properties of pH-switchable surfactants based on dynamic imine bond Li Huan,Fang Yinjun,Liu Xuefeng 2021, 51 (11):  1039-1044.  doi: 10.3969/j.issn.1001-1803.2021.11.001 Abstract ( 284 )   HTML ( 65 )   PDF (1411KB) ( 203 )   Based on the particular pH-response of dynamic imine bonds, constructing pH-responsive surfactants and the self-assemblies thereof has been one of the hotspots recently in the field of physical chemistry of surfactants. However, the reports on amphoteric surfactants containing dynamic imine bonds with simple structure have been rarely seen. Herein, an aromatic aldehyde containing sulfobetaine group （FPSA, （CHO）C6H4OCH2CH2N+（CH3） 2CH2CH2CH2SO3-） was designed and synthesized. FPSA and octylamine （OA） were used as the precursors to form an amphoteric dynamic imine surfactant （FPSA-OA, C8H17N=CH-C6H4OCH2CH2N+（CH3） 2CH2CH2CH2SO3-） in situ in the aqueous solution. The critical micelle concentration （cmc） and the surface tension （γ） at cmc were 3.43×10-3mol/L and 30.89 mN/m at 25 ℃, respectively. In addition, the interfacial tension at the interface of petroleum ether-water was reduced to 4.87 mN/m. All of these results indicate that the interfacial activities of FPSA-OA are quite well. The pH-response of FPSA-OA was observed, and the pH-responsive window was in the range of 8 to 12. For a sample solution of FPSA-OA （2×10-3mol/L）, the value of γ was reduced from approximately 70 mN/m to 37 mN/m when the pH was changed from 8 to 12, and then restored to approximately 70 mN/m if the pH was changed back to 8. This transition could be steadily and reversibly carried out over 5 cycles without any remarkable variation, which implies that FPSA-OA has an excellent pH-reversibility. Figures and Tables | References | Related Articles | Metrics

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Removal of residual hydrogen peroxide after bleaching by microspheres containing catalase Chen Jialin,Liu Gang,Sun Mengmeng,Guo Ting,Meng Tao 2021, 51 (11):  1045-1051.  doi: 10.3969/j.issn.1001-1803.2021.11.002 Abstract ( 201 )   HTML ( 10 )   PDF (1494KB) ( 252 )   Calcium carbonate microspheres containing catalase were prepared by the method of bionic mineralization. The size and pore size of the enzyme-carrying microspheres were measured; the encapsulation efficiency, loading capacity and stability of the enzyme-carrying microspheres in harsh environments were studied; the removal of residual hydrogen peroxide from the gauze after bleaching was studied. The results show that the enzyme-carrying microspheres have a particle size of approximately 11 μm. From the nitrogen adsorption-desorption isotherm and pore size distribution diagram, it can be seen that CAT@CaCO3 microspheres have uniformly distributed pores （approximately 5.53 nm）, which can well encapsulate catalase （approximately diameter 6 nm×10 nm）, allowing the substrate H2O2 and the product H2O to diffuse freely. Under the condition that the mass concentration of catalase is 0.15 mg/mL, the microsphere has a maximum load of 24.26 mg/g for catalase. Meanwhile, the enzyme encapsulation rate is 98%, and the enzyme activity retention rate is 72%, indicative of the mildness of the method of enzyme immobilization. Compared with free enzymes, the enzyme-carrying microspheres have improved thermal stability （38.99% of relative enzyme activity can still be retained at 80 ℃） and have changed the trend of catalase tolerance to different pH environments （the optimal pH for the enzyme activity shifts from pH 8 to pH 11）. This phenomenon may be ascribedto the mineralization and fixation of calcium carbonate changing the conformation of the enzyme. To a certain extent, the conformation of CAT is changed, resulting in a different tendency of pH tolerance from free enzymes. In addition, the anti-surfactant performance of the enzyme-carrying microspheres is improved （85.82% of relative enzyme activity remains in the presence of sodium lauryl sulfate）. The reasons might be that the calcium carbonate mineral shell can stabilize the three-dimensional structure of the enzyme during the process of immobilizing the enzyme, resulting in the enhanced stability of the immobilized enzyme. Finally, the enzyme-carrying microspheres can completely remove the residual hydrogen peroxide from the gauze after bleaching within 25 min, which has a faster removal rate than the free enzyme （35 min）. Figures and Tables | References | Related Articles | Metrics

Lecture of science and technology

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Botanical cosmetic ingredients （VI）Research and development of anti-aging skincare ingredients from plants Zhang Yutong,Wei Mengya,Ren Qianqian,Wu Hua,Jin Jianming 2021, 51 (11):  1052-1059.  doi: 10.3969/j.issn.1001-1803.2021.11.003 Abstract ( 554 )   HTML ( 45 )   PDF (1285KB) ( 577 )   Among the changes of skin with age, skin aging is one of the most obvious evidence. During this process, the epidermis gradually becomes thinner, and its self-repairing capability is gradually weakened. In addition, the amounts of collagen and elastin in the skin gradually reduce, and thus the skin loses elasticity. Skin aging is inevitable, but a varity of anti-aging strategies can be adopted. Herein, the intrinsic and extrinsic factors leading to skin aging have been introduced, as well as some skin anti-aging strategies. Some of plant extracts can exhibit skin anti-aging effects via multiple ways, such as preventing skin photoaging by sun-screening ingredients, inhibiting skin aging by various bioactive components, and reducing skin wrinkles and pigment spots by skin peeling which activates the proliferation and metabolism of keratinocytes. The anti-aging skincare ingredients from plants have been introduced, including polyphenols, flavonoids, vitamins and carotenoids which promote the biosynthesis （or inhibit the degradation） of collagen, elastin and hyaluronic acid. Plant hydroxy acids used for skin peeling have also be introduced. The description of the anti-aging skincare ingredients from plants may provide a reference for the application of plant extracts in anti-aging cosmetics. Figures and Tables | References | Related Articles | Metrics

Development and application

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pH-responsive vesicles based on dynamic covalent bond Mu Meng,Zhang Xing,Jiang Yan,Li Jianbing,Lu Pingping,Zhang Yongmin 2021, 51 (11):  1060-1066.  doi: 10.3969/j.issn.1001-1803.2021.11.004 Abstract ( 751 )   HTML ( 20 )   PDF (1669KB) ( 541 )   Over the past decades, stimuli-responsive colloidal materials based on dynamic covalent bonds （especially imine bonds） have aroused significant interest due to the combination of the stability of covalent bonds and the tunability of non-covalent bonds. However, conventional imine-type surfactants are usually switched between active and inactive states. Tuning the symmetry of surfactants using the dynamic imine bonds has barely been reported to date. Herein, a novel imine-type surfactant bearing approximately symmetrical double tails was fabricated utilizing a simple Schiff base reaction by mixing aldehyde-containing surfactant （（N-alkyl-N,N-di-methyl-N-（2-（4-formyl-phenoxy）ethyl） ammonium bromides, HOBAB） and n-octylamine （OA） at a fixed stoichiometric ratio of 1∶1 in water. Both the results of 1H NMR and FT-IR manifested the formation of dynamic imine bonds, and the conversion rate from aldehyde to imine was as high as 80.75%. With alternatively adding HCl （pH=5.0） and NaOH （pH=10.0）, the surfactant could be reversibly switched between highly asymmetrical HOBAB and approximately symmetrical imine-type double-tail amphiphile because of the breakage and formation of imine bonds. Surface tension experiment showed that the critical micelle concentration of the sample at pH=10.0 was decreased by at least one order of magnitude compared to that at pH=5.0, owing to the presence of imine-type double-tail surfactant. Furthermore, in contrast with HOBAB, the presence of imine-type double-tail amphiphiles remarkably improved the surface/interfacial properties （larger pc20 values and more compact packing at the air/solution interface）. More importantly, this imine-type double-tail surfactant could spontaneously self-assemble into vesicles with radius being approximately 70 nm in aqueous solution, because of the favorable molecular geometry. When the pH value was decreased to 5.0, vesicles had disappeared and spherical micelles with radius being ~2.5 nm re-dominated in the solution, which was mainly ascribed to the change of molecular geometry originated from the breakage of imine bonds. As pH value was increased to 10.0 again, small spherical micelles re-evolved into large vesicles due to the re-formation of imine-type double-tail surfactant. In a word, upon cyclically changing the pH value between 5.0 and 10.0, the aggregates that dominate the solution can be reversibly changed between spherical micelles and vesicles because of the reversible change in molecular geometry between high asymmetry and approximate symmetry. The current research may facilitate the design of new stimuli-responsive soft materials based on dynamic covalent bonds. Figures and Tables | References | Related Articles | Metrics

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Preparation and performance evaluation of the nanoemulsion based on rhamnolipid Zhang Zhi,Hu Xuyan,Yuan Hui,Li Yanchuang 2021, 51 (11):  1067-1072.  doi: 10.3969/j.issn.1001-1803.2021.11.005 Abstract ( 331 )   HTML ( 13 )   PDF (1750KB) ( 244 )   To enhance the low oil production rate in low-permeability reservoir development, the nanoemulsion based on rhamnolipid was prepared by diluting the microemulsion. The effects of the mass ratio of surfactant to cosurfactant （Km）, temperature, and inorganic salts on the pseudo-ternary phase diagram and the droplet diameter were studied. Finally, the oil displacement efficiency of the nanoemulsion was evaluated. The results show that the area of the monophase microemulsion zone is first increased and then decreased with the increase of Km. The area of the monophase microemulsion zone reaches a maximum at Km=3. With the increase of temperature, the area of the monophase microemulsion zone is also first increased and then decreased. The maximum area of the monophase microemulsion zone is observed at 323.15 K. The area of the monophase microemulsion zone is increased with the concentrations of NaCl and CaCl2. The addition of inorganic salts has reduced the critical micelle concentration of rhamnolipid and thus increased the miscibility of oil and water phases. When the mass fraction of water is lower than 80%, the droplet diameter is slightly increased with the increase of the storage time. In addition, the nanoemulsion shows excellent temperature and salt resistance. Core displacement experiment shows that nanoemulsion flooding can decrease the injection pressure of water flooding and can improve the recovery by 17%. Therefore, the nanoemulsion has the potential in enhancing oil recovery of low-permeability reservoirs. Figures and Tables | References | Related Articles | Metrics

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Research on the influence of surfactant on foaming and wetting performance Gong Jiayi,Qiao Jianjiang 2021, 51 (11):  1073-1079.  doi: 10.3969/j.issn.1001-1803.2021.11.006 Abstract ( 658 )   HTML ( 36 )   PDF (1432KB) ( 482 )   This paper is intended to explore the influence of the surfactant solution physical parameters and compound components on the foaming and wetting performance by preparing surfactant solutions of different systems. Physical parameters includes the HLB value of surfactant, solution surface tension, and its viscosity. The HLB value of the solution was measured by water counting, and its surface tension and viscosity were measured by the surface tension instrument and rotational viscometer, respectively. Foaming ability of the solution was determined by the shaking method and Warning-Blender method, while foam stability was determined by the foam volume attenuation method. The wetting time was determined by the immersion method. The nonionic-nonionic surfactant system solution was formulated from Tween 85, Tween 40, alkyl glycoside （APG） to change the HLB value of the solution. Results show that the HLB value has no obvious effect on the foaming and wetting performance. Within the test range, when the APG concentration is the same, the solution has similar foaming and wetting performance, indicating that the foaming and wetting performance of the solution mainly depends on the effect of APG concentration. The anionic-nonionic surfactant system solution is formulated from sodium dodecyl sulfate （SDS） and APG to change the surface tension of the solution. Results show that the decrease of surface tension is conducive to the improvement of foaming and wetting performance. When the concentration is greater than the critical micelle concentration （0.011 6%）, the surface tension is almost constant. With the increase of concentration, foaming ability of the solution increases first and then stabilizes, the foam stability decreases and the wetting performance improves. In the compound solution of SDS, APG and xanthan gum, the concentration of xanthan gum is different to change the viscosity of the solution. Results show that the increase of solution viscosity is beneficial to the improvement of foam stability, and the foam can carry more solutions in the initial stage of formation. The foaming ability of the solution is slightly reduced, and the wetting performance decreases. The synergistic effect of surfactant compounding is related to the composition and ratio concentration. The combination of sodium lauryl polyoxyethylene ether sulfate （SLES） and dodecyl dimethyl betaine （BS） has a synergistic effect, and the comprehensive performance is the best when the concentration ratio is 5∶5. Figures and Tables | References | Related Articles | Metrics

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Synthesis, characterization and esterification kinetics of epoxidized soybean oil based water soluble alkyd resin Ma Baifeng,Zhen Weijun,Ouyang Chenguang,Abulajiang Yusupu,Ou Quansheng 2021, 51 (11):  1080-1087.  doi: 10.3969/j.issn.1001-1803.2021.11.007 Abstract ( 364 )   HTML ( 8 )   PDF (1635KB) ( 277 )   Epoxidized soybean oil （ESO）, trimethylolpropane （TMP）, phthalic anhydride （PA） and water-soluble monomer trimellitic anhydride （TMA） were used as the main raw materials to prepare water-soluble alkyd resin by alcoholysis, esterification and neutralization. With the static contact angle as the objective function, the synthesis conditions of water-soluble alkyd resin were optimized by the orthogonal experiment. The structure of the water-soluble alkyd resin was characterized. The results of Fourier transform infrared （FTIR） show that the water-soluble alkyd resin is successfully synthesized. The optimum conditions obtained by orthogonal test are as follows: the oil content is 40%; the alcohol excess is 1.2; the molar ratio of TMA to PA is 0.5∶1; the final acid value is controlled at 60-80 mg KOH/g. Through the transmittance testing and storage stability testing, the prepared water-soluble alkyd resin shows excellent water solubility and stability, indicating that epoxidized soybean oil can be used as the raw material for manufacture of waterborne alkyd coatings. The rotational rheological analysis shows that the water-soluble alkyd resin has good rheological properties and conforms to the pseudoplastic fluid. Esterification kinetics analysis shows that temperature has significant effect on the esterification reaction. With the increase of temperature, the reaction rate and conversion rate are significantly improved. The study on esterification kinetics finds that it conforms to the second-order reaction kinetics model, and the activation energy Ea of esterification reaction is 88.081 kJ/mol according to Arrhenius equation. Figures and Tables | References | Related Articles | Metrics

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Transdermal absorption and safety assessment of six commonly used sun-screening agents Liu Yafeng,Liu Daizheng,Xie Zhenming 2021, 51 (11):  1088-1094.  doi: 10.3969/j.issn.1001-1803.2021.11.008 Abstract ( 485 )   HTML ( 29 )   PDF (1297KB) ( 388 )   The widespread use of sunscreen has caused great concern about its safety. Using sunscreen products can protect the skin from UV radiation, meanwhile, it may cause damage to the human body if it intervenes the circulatory system through the skin. In this study, the transdermal absorption of six sun-screening agents in full-thickness porcine ear skin was examined. The effects of skin condition, application dose, composition of receptor fluid, and retention of sun-screening agents at different skin depths were investigated. The results show that skin condition can affect the transdermal absorption of sun-screening agents, and the sun-screening agents can penetrate through frozen skin more easily. The penetration coefficient of each sun-screening agent was from 0.47 to 0.88. When the dosages were 0.5 mg and 2 mg, the transdermal absorption values of the sun-screening agents were different and increased with the increase of dosage, but the relationship was not linear. Adding different nonionic additives into the receptor fluid had little effect on the transdermal absorption of the sun-screening agents. The retention of the sun-screening agents in each layer of skin was related to their physical and chemical properties, such as molecular weight, water-oil balance coefficient, etc. Twenty-four hours after application, the transdermal absorption rate of BP-3 was 36.66%, higher than other sun-screening agents, and the margin of safety was 96.15. In general, the amounts of the sun-screening agents absorbed through the skin are relatively small and the health risks are low when the legally permitted dosages are used. Figures and Tables | References | Related Articles | Metrics

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Study on chemical components, antioxidant activity and cognitive improvement of borneol essential oil Tang Yin,Lv Xiaofan,Wang Ying,Wu Yani 2021, 51 (11):  1095-1101.  doi: 10.3969/j.issn.1001-1803.2021.11.009 Abstract ( 347 )   HTML ( 13 )   PDF (1303KB) ( 186 )   Gas chromatography-mass spectrometry （GC-MS） technology was used to detect chemical compositions and their relative contents of borneol essential oil. By analyzing scavenging activity of 2,2-Diphenyl-1-picrylhydrazyl （DPPH） free radical and 2,2'-azinobis[3-ethylbenzothiazoline-6-sulfonicacid]-diammonium salt （ABTS） free radical, the antioxidant activity of borneol essential oil and trolox were determined in vitro. In order to explore the effect of borneol essential oil on behavior of mice with learning and memory impairment, Morris water maze test and immunohistochemistry experiment were used to judge the cognitive function of mice in normal group, model group, borneol essential oil group and positive group. In addition, after completing the animal behavior experiment, the levels of superoxide dismutase （SOD）, glutathione peroxidase （GSH-PX） and malondialdehyde （MDA） of brain tissue were measured. The results show that there are 43 main chemical components in borneol essential oil, such as borneol, d-limonene and 1,8-cineole. Free radical scavenging experiment finds that a certain concentration of borneol essential oil can effectively clean up DPPH and ABTS free radical, but its scavenging ability is less than trolox. The half maximal inhibitory concentration （IC50） of borneol essential oil on DPPH and ABTS free radical are 1.65 and 2.27 g/L, respectively. In Morris water maze, compared to mice in model group, the escape latency and crossing times of mice in borneol essential oil group are improved, and the performance of mice in borneol essential oil group is close to that in positive group. In immunohistochemistry experiment, the immunohistochemical section indicates that compared to mice in model group, the β-amyloid protein of mice in borneol essential oil group decreases, and the situation of mice in borneol essential oil group is close to that in positive group. Compared to mice in model group, the activities of SOD and GSH-PX increase, and the content of MDA decreases in brain tissue of mice in borneol essential oil group. In conclusion, borneol essential oil has certain antioxidant activity in vitro and in vivo, and can improve cognitive impairment in mice. Figures and Tables | References | Related Articles | Metrics

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Study on synthesis and whitening activity of isoferic acid amides Luo Tianji,Mei Zikun,Song Jingjiu,Zhu Jun 2021, 51 (11):  1102-1108.  doi: 10.3969/j.issn.1001-1803.2021.11.010 Abstract ( 236 )   HTML ( 9 )   PDF (1202KB) ( 363 )   Using isoferulic acid and amino acid ethyl ester hydrochloride as raw materials, 1- （3-dimethylaminopropyl）-3-ethylcarbodiimide hydrochloride （EDC HCl） and 1-hydroxybenzotriazole （HOBt） as catalysts, isoferuloyl-alanine ethyl ester （a）, isoferuloyl-phenylalanine ethyl ester （b）, isoferuloyl-leucine ethyl ester （c）, isoferuloyl-isoleucine ethyl ester （d）, isoferuloyl-valine ethyl ester （e）, isoferuloyl-methionine ethyl ester （f） were synthesized by EDC condensation. The structure of the products was characterized by nuclear magnetic resonance （1H NMR） and high performance liquid chromatography-mass spectrometry （HPLC-MS）. The whitening activity of ethyl isoferulyl-amino acid was detected by two in vitro non-cellular experiments of scavenging DPPH free radicals and inhibiting tyrosinase activity. It can be seen from the experimental results that the six isoferulyl amino acids have a good ability to scavenge DPPH free radicals, which are higher than that of isoferulic acid. Isoferulyl-alanine ethyl ester has the strongest ability to scavenge DPPH free radicals. Its IC50 value reaches 1.13 mg/mL. It also has a certain inhibitory effect on tyrosinase activity, of which isoferulyl-alanine ethyl ester has the best effect, with the inhibition rate of 95.43%. The results of B16 melanoma cells show that isoferulyl-alanine ethyl ester, isoferulyl-phenylalanine ethyl ester and isoferulyl-methionine ethyl ester have better inhibitory effects on melanin than isoferulic acid at 2 mg/mL mass concentration and its irritation is reduced. The differences in the efficacy of the six products may be due to the different types of side chain amino acids on each substance. In the follow-up investigation, the biological activity of isoferulyl amino acid derivatives can be analyzed to clarify the relationship between the molecular structure of the substance and the physiological activity, and to increase the transdermal absorption effect and safety of the substance in animal experiments. Figures and Tables | References | Related Articles | Metrics

Reviews

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Influencing factors on washing performance of alkaline protease in liquid detergent Wang Penghui,Wang Weixian,Yang Tao,Zeng Hui,Rui Zebao,Li Donghua,Huang Ping 2021, 51 (11):  1109-1117.  doi: 10.3969/j.issn.1001-1803.2021.11.011 Abstract ( 379 )   HTML ( 20 )   PDF (1330KB) ( 407 )   Alkaline protease is one of the most widely used enzymes in liquid detergents. It has a wide range of peptide bond hydrolysis selectivity and can degrade a variety of protein souls. However, unlike the biological environment, various inactivation factors in the harsh liquid detergent environment may lead to the denaturation, performance degradation and cost increase of alkaline protease. Understanding these influencing factors in the complex liquid protease environment is necessary for further improving the washing performance of alkaline protease. This paper firstly addresses the main inactivation factors of alkaline protease in liquid detergent, such as autolysis inactivation and the effect of chelating agent, bleaching agent and surfactant. Special attention is paid to the interaction between surfactant and alkaline protease. Finally, the development of surfactant types and compounding technology in liquid detergent formulation in the future is prospected. Figures and Tables | References | Related Articles | Metrics

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Research progress on the types and mechanisms of non-physiological alopecia Yu Xiaoqian,Ma Yuchen,Ding Wenyu,Hu Yiqiong,Jia Yan,He Congfen 2021, 51 (11):  1118-1124.  doi: 10.3969/j.issn.1001-1803.2021.11.012 Abstract ( 411 )   HTML ( 27 )   PDF (1223KB) ( 674 )   Non-physiological alopecia refers to a phenomenon that severely affects the appearance of patients, such as a heavy loss of hair leading to thinning hair or receding hairline. According to the different causes, it can be categorized into androgenic alopecia （AGA）, immunodeficiency alopecia （IDA）, skin damage alopecia （SDA）, nutritional abnormalities alopecia （NAA） and drug-induced alopecia （DIA）. All these types of hair loss are caused by corresponding factors that directly or indirectly act on hair follicles. Among them, the pathological processes of AGA and IDA have been reported a lot. As for AGA, hair follicles are sensitive to androgens, leading to disorder of growth cycle; as for IDA, the breakdown of hair follicle immune pardon mechanism makes immune cells attack hair follicles. The reasons for SDA and NAA are relatively straightforward. They are caused by skin damage and nutrient deficiency, respectively, which lead to disorder of the physiological cycle of hair follicles and affect hair growth. There are many factors influencing DIA, which vary according to different drugs. Herein, the mechanisms of non-physiological alopecia caused by various reasons have been briefly described. Research results of non-physiological alopecia are focused on. It may provide a better understanding of the causes and mechanisms of non-physiological alopecia, which might help researchers to find a way to prevent hair loss. Figures and Tables | References | Related Articles | Metrics

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Technical comparison and trend analysis on the topics that ICCR are concerned with Su Zhe,Luo Feiya,Xing Shuxia,Wang Gangli 2021, 51 (11):  1125-1133.  doi: 10.3969/j.issn.1001-1803.2021.11.013 Abstract ( 234 )   HTML ( 11 )   PDF (1083KB) ( 348 )   The topics of concern that the International Cooperation on Cosmetics Regulation （ICCR） has focused on from 2008 to 2020 have been reviewed. Corresponding technical documents and research progress in regulations and technologies of cosmetics have also been reviewed. Trend analysis and technical comparison have been completed. The prospects of future cosmetic science in China have been discussed. It is proposed to revise the technical regulations dynamically to continuously improve the standards. Technical progress of ICCR in several directions can be followed up, especially in safety evaluation, nanomaterials, ISO standard evaluation and allergens. The development and verification of alternative methods, as well as the study and application of integrated strategies, should be accelerated. The regulatory system for nanomaterials and the technical system for nanotechnology in cosmetics should be established and improved in China. In addition, attentions can also be paid to some advanced research work of ICCR, for example, the next generation risk assessment and microbiome. To implement the Regulations on the Supervision and Administration of Cosmetics, corresponding technical support and technical preparation should be speeded up. Figures and Tables | References | Related Articles | Metrics

Analytical methods and testing

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Determination of multiple elements in toothpaste by inductively coupled plasma mass spectrometry （ICP-MS） Wu Li,Zhou Juanjuan,Fang Fang,Feng Youlong,Cao Ling 2021, 51 (11):  1134-1141.  doi: 10.3969/j.issn.1001-1803.2021.11.014 Abstract ( 227 )   HTML ( 12 )   PDF (988KB) ( 297 )   A method for the determination of multiple elements in toothpaste by ICP-MS was established. Microwave digestion was used for sample pre-treatment. Rh and Re were used as the internal standard. The contents of 23 kinds of elements in toothpaste, including Mg, Al, K, Ca, Ti, Cr, Mn, Fe, Ni, Cu, Zn, As, Se, Sr, Mo, Ag, Cd, Sn, Sb, Ba, Hg, Tl and Pb were determined by ICP-MS. The internal standard method was used for quantitative analysis. The results show that the correlation coefficient of the calibration curve is over 0.998 8 for all the analyzed elements. RSD of repeatability test ranges from 2.5% to 9.5% （n=6）. The recovery of low, medium and high concentration （n=9） ranges from 85.6% to 105.9%. The method is sensitive, specific, simple, rapid and accurate. It is suitable for the determination of multiple elements in toothpaste. Figures and Tables | References | Related Articles | Metrics

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Simultaneous determination of 26 prohibited substances in masks by ultra performance liquid chromatography-triple quadrupole mass spectrometry Du Hui,Ren Jing 2021, 51 (11):  1142-1149.  doi: 10.3969/j.issn.1001-1803.2021.11.015 Abstract ( 156 )   HTML ( 13 )   PDF (1340KB) ( 216 )   An ultra performance liquid chromatography-triple quadrupole mass spectrometric （UPLC-MS/MS） method was developed for simultaneous separation and determination of 26 prohibited substances in commercially available masks, which contained glucocorticoid, quinolones and imidazole derivatives. The samples were dispersed in saturated sodium chloride solution and were extracted with acetonitrile. After removal of macromolecular matrix by potassium ferrocyanide and zinc acetate, the samples were purified by solid phase extraction. The binary gradient elution was performed with acetonitrile （containing 0.1% acetic acid）-0.1% acetic acid solution, and the multi-reaction monitoring was used for analysis. All the 26 compounds show a good linear relationship in their respective concentration ranges, and the correlation coefficients （r） are no less than 0.995. The limits of detection （LODs） range from 1 to 80 ng/g. The limits of quantification （LOQs） are in the range of 4-380 ng/g. The average recoveries of 26 prohibited substances in masks range from 86.4% to 115.2%. The method is simple, accurate and sensitive. It can be used for quantitative analysis of prohibited substances in commercially available masks. Figures and Tables | References | Related Articles | Metrics

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Analysis of volatile components in Asarum heterotropoides by HS-SPME/GC-MS Wang Feng,Li Nan,Li Xue,Zhong Lingyan,Huang Zetian,Hu Ping 2021, 51 (11):  1150-1157.  doi: 10.3969/j.issn.1001-1803.2021.11.016 Abstract ( 167 )   HTML ( 7 )   PDF (1356KB) ( 245 )   Asarum is a kind of commonly used traditional Chinese medicine, and volatile oil is the main material basis for its efficacy. In traditional studies, the volatile oil is extracted by steam distillation and analyzed by GC-MS. Although the extraction method is easy to operate and has low cost, it is time-consuming, large sample consumption, high extraction temperature and easy thermal decomposition of active components. Moreover, xylene is often added in this method to promote the stratification of volatile oil, which brings great interference to the subsequent GC-MS analysis and component identification of volatile oil. Therefore, Solid Phase Microextration （SPME） technology that integrates extraction, purification, enrichment, and sampling functions was used to analyze the volatile oil of Asarum for the first time. The HS-SPME/GC-MS method was established to analyze Asarum heterotropoides, and the volatile components were identified by the NIST spectral library search and retention index. A total of 68 components are identified from the volatile oil of Asarum heterotropoides from 6 origins. The relative content of methyl eugenol is the highest among the volatile components with peak area percentages ranging from 17.20% to 33.80%. The application of HS-SPME/GC-MS method to the study of the volatile components in Asarum heterotropoides can reflect the overall differences, and the method is simple and rapid, providing new ideas for the quality evaluation of Asarum heterotropoides. Figures and Tables | References | Related Articles | Metrics

Editorial office article column

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Development trend and countermeasures of academic journals in daily chemical field Liu Yanhong,Zhang Jing,Zhou Ting,Yang Xu,Yang Yuxi 2021, 51 (11):  1158-1162.  doi: 10.3969/j.issn.1001-1803.2021.11.017 Abstract ( 226 )   HTML ( 18 )   PDF (887KB) ( 292 )   In response to a call for President Xi Jinping of “running well first-class academic journals and all kinds of academic platforms, strengthening domestic and international academic exchanges”, carrying out research on the development trend of academic journals, enhancing the influence and management ability of academic journals by predicting risks and seizing opportunities so as to promote academic innovation. This paper stated the current situation of academic journal in the field of daily chemical industry, summarized and analyzed its characteristics and development trend, emphatically put forward countermeasures for the future development of daily chemical academic journals from four aspects including system concept innovation, integration path optimization, user demand experience improvement and editorial staff professional ability improvement. References | Related Articles | Metrics