Table of Content

22 June 2022, Volume 52 Issue 6 Previous Issue    Next Issue

Basic research

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Rheological behavior and synergistic mechanism of the mixed system of hydroxyethyl cellulose and γ-polyglutamic acid Chen Hanjun,Zhuang Jie,Wu Xu,Shen Xingliang,Zhang Wanping,Zhang Qianjie 2022, 52 (6):  577-584.  doi: 10.3969/j.issn.1001-1803.2022.06.001 Abstract ( 331 )   HTML ( 312 )   PDF (1433KB) ( 443 )   The rheological properties of the mixed system of hydroxyethyl cellulose （HEC） and γ-polyglutamic acid （γ-PGA） were systematically studied by investigating the apparent viscosity, flow curves, viscoelasticity, viscosity-temperature curves and other rheological properties. The microstructure of the mixed system of HEC and γ-PGA was also characterized. The experimental results showed that HEC and γ-PGA had synergistic effect of increasing viscosity at different mass ratios when the total mass fraction of HEC and γ-PGA was 1.2%, in which the synergistic effect of increasing viscosity was most obvious when the mass ratio of HEC/γ-PGA was 2∶1. Single HEC system, single γ-PGA system and mixed HEC/γ-PGA system were all shear thinning fluids, and their flow curves could be well fitted by Cross equation, and the correlation coefficients （R） were all greater than 0.999. Compared with the single systems of HEC and γ-PGA, the range of linear viscoelastic region of the mixed HEC/γ-PGA system increased, i.e., the overall strain resistance of the mixed HEC/γ-PGA system was enhanced. In frequency scanning, the intersection of elastic modulus （G'） and viscous modulus （G''） of HEC and γ-PGA mixtures moved to the low frequency direction, indicating that the mixed system was more elastic than the single system. Meanwhile, with the increase of temperature, the apparent viscosities of single HEC, single γ-PGA and mixed HEC/γ-PGA systems were decreased to varying extent. The viscosity-temperature curves of these systems could be well fitted by the Arrhenius equation, and the correlation coefficients were greater than 0.996. For the mixed HEC/γ-PGA system, the elastic feature was dominant when the temperature was lower than 45 ℃, while the viscous feature was dominant when the temperature was higher than 45 ℃. In addition, the physical entanglement and three-dimensional network structure were strengthened after mixing HEC and γ-PGA, as shown in microstructure observation. Figures and Tables | References | Related Articles | Metrics

Lecture of science and technology

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Preparation, properties and applications of natural biomass materials （Ⅵ） Straight or branched energy storage polysaccharide from plants: starch Wang Changyun,Hao Yang,Fan Jianru,Tang Wenjun,Xu Guiyun,Fan Jinshi 2022, 52 (6):  585-593.  doi: 10.3969/j.issn.1001-1803.2022.06.002 Abstract ( 298 )   HTML ( 28 )   PDF (1415KB) ( 364 )   Starch is the plant energy storage polysaccharide in nature, usually occurring as granules. A starch from a specific plant source is unique among starches, i.e., starch granules from the various plant sources differ in appearance, particle size distribution, fine structure of the constituent polymer molecules and physical properties. Granular starch is generally composed of two types of molecules, amylose and amylopectin. Amylose is a predominantly linear （1,4）-α-D-glucan, although some amylose molecules are slightly branched. Amylopectin has a branch-on-branch structure consisting of mostly short chains of （1,4）-linked α-D-glucopyranosyl units linked to other short, linear chains via α-（1,6） branch points. The amylopectin fraction is composed of much larger molecules than those of amylose. Different molecular structures and size, amylose/amylopectin ratios, and granular architectures give each type of starch its unique properties. Due to the special characteristics of native non-toxicity, renewability, broad sources and biodegradability, starch has been widely used in food, medicine, papermaking industry, cosmetics, etc. Furthermore, after physical, chemical and biological modification, starch can be endowed with more diverse molecular structure and more abundant functional properties, which may greatly improve its applied properties and extend its application fields. Herein, the structure, source, physical and chemical properties, typical production methods, main modification methods and recent application advance of starch are introduced, and the research trend and development prospect of starch in the future are also pointed out. Figures and Tables | References | Related Articles | Metrics

Development and application

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Preparation and surface-active properties of dehydroabietyl polyoxyethylene glycidyl ether grafted hydroxyethyl chitosan Huang Xujuan,Wang Ting,Ding Zhengqing,Yang Xinxin,Cai Zhaosheng,Shang Shibin 2022, 52 (6):  594-600.  doi: 10.3969/j.issn.1001-1803.2022.06.003 Abstract ( 196 )   HTML ( 20 )   PDF (1339KB) ( 164 )   Dehydroabietol polyoxyethylene（5） ether （DA（EO）5H） was condensated with epichlorohydrin in the presence of boron fluoride diethyl etherate firstly. Then, dehydroabietyl polyoxyethylene glycidyl ether （DA（EO） 5GE） was obtained through dehydrochlorination of the condensation product in the presence of NaOH. Finally, DA（EO） 5GE grafted hydroxyethyl chitosan （DA（EO） 5GE-g-HECTS）, a polymeric surfactant with hydrogenate phenanthrene ring as main lipophilic group, sugar chain of hydroxyethyl chitosan （HECTS） as main hydrophilic group, and polyoxyethylene chain as assist lipophilic-hydrophilic structure, was prepared through the grafting modification of DA（EO） 5GE to water-soluble HECTS. The structure of the grafted product was characterized by Fourier transform infrared （FT-IR）, 1H nuclear magnetic resonance 1H NMR and UV-Vis spectrophotometry. The grafting degree （DG） of products were characterized using elemental analysis, and their surface-active activities and emulsifying capacity were investigated using surface tension method and emulsion stabilization time method, respectively. The result show that the DA （EO） 5GE-g-HECTS with different DG can be prepared by using different raw material ratio. When the DG of DA（EO） 5GE-g-HECTS increases from 12.98% to 31.73%, the critical micelle concentration （cmc） decreases from 0.378 g/L to 0.249 g/L. The emulsions are prepared by blending 50% （φ/%） liquid paraffin and 50% （φ/%） DA（EO） 5GE-g-HECTS aqueous suspensions. The emulsifying capacity of DA（EO） 5GE-g-HECTS increases at first and then decreases with the increasing DG. When the DA（EO）5GE-g-HECTS4 （its DG is 28.33% and the mass concentration is 1.0 g/L） is utilized as emulsifier, the stability time of emulsion composed of liquid paraffin and water is 565 s. It is better than the TX-10 emulsifier which is 165 s at the same condition. Figures and Tables | References | Related Articles | Metrics

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Study on the synthesis of 2-heptyl chloroacetate from methyl chloroacetate by using ionic liquid as a catalyst Wang Mengfei,Du Lianzhi,Xu Jianghui,Bai Dongrui,Zhang Yan,Chao Jianping 2022, 52 (6):  601-605.  doi: 10.3969/j.issn.1001-1803.2022.06.004 Abstract ( 205 )   HTML ( 15 )   PDF (1254KB) ( 264 )   2-Heptyl chloroacetate is an important intermediate for synthesizing new pesticides and herbicides. Conventional esterification reactions often use traditional strong acids, which is harmful to equipment and shows low product yield. Using ionic liquids as solvents or catalysts can make the reaction conditions stable, recyclable and environment-friendly, and lead to high product yield. Herein, the transesterification reaction between methyl chloroacetate and 2-heptanol was studied. Four ionic liquid catalysts were synthesized, including 1-methyl-3-（propyl-3-sulfonic acid） imidazole p-toluenesulfonic acid salt [MIM-PS][PTSA], 1-butyl-3-methylimidazole hydrosulfate [BMIM] HSO4, 1-methyl-3-（propyl-3-sulfonic acid） imidazole hydrosulfate [MIM-PS][HSO4] and N-methylimidazole phosphoric acid salt [HMIM] H2PO4. These four ionic liquid catalysts were used in a transesterification reaction. According to the product yield of the transesterification reaction, the optimal catalyst [MIM-PS] [PTSA] was screened. The effects of ester-alcohol ratio, reaction temperature, reaction time, catalyst dosage and catalyst cycle were investigated in the presence of [MIM-PS][PTSA]. The results showed that, for the reaction between methyl chloroacetate and 2-heptanol, 5% [MIM-PS][PTSA] catalyst was added, the reaction temperature was 100 ℃, and the reaction time was 6 h, indicative of a yield of 76.3%. When the ionic liquid was reused for three times, the yield of 2-heptyl chloroacetate was still greater than the 95% of the initial yield. When the catalyst was more than 5% or the temperature was too high, by-products such as 2-heptene or 2-heptyl ether might be formed. When the reaction time was too long, the product might undergo substitution reaction to form corresponding ether compounds. In this work, ionic liquids were used as solvents or catalysts, and the reaction conditions were stable, recyclable and environment-friendly, and the product yield was high, which could provide reference for the conditions of process amplification. Figures and Tables | References | Related Articles | Metrics

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Analysis of phosphorus adsorption performance and adsorption kinetics of phosphogypsum in loess soil Xuan Chao,Hu Changrong,Yi Yun,Liu Fei,Cao Jianxin,Pan Hongyan 2022, 52 (6):  606-612.  doi: 10.3969/j.issn.1001-1803.2022.06.005 Abstract ( 158 )   HTML ( 20 )   PDF (1367KB) ( 138 )   The effects of PG on the phosphorus adsorption capacity of loess soil and the influence mechanism therein were investigated to provide some scientific basis for the resource utilization of phosphogypsum （PG） in agriculture. The effects of different PG dosages on the phosphorus adsorption properties and the adsorption kinetics were analyzed in loess soil with different incubation time. The results showed that the dosage of PG had a significant effect on the adsorption of phosphorus in loess soil （P<0.05）. The phosphorus adsorption capacity was increased first, and then decreased with the increase of PG addition and reached the highest value at 0.5 g PG/100 g soil. Compared with the original soil, the phosphorus adsorption capacity and the content of amorphous iron oxide （Feo） were increased by 2.80% and 2.33%, respectively, and the pH was increased from 3.77 to 4.00. Moreover, the phosphorus adsorption kinetic process of the mixed soil samples fitted the pseudo-first-order kinetic models with PG content of 0.5 g/100 g soil and 1.0 g/100 g soil, and then fitted the pseudo-second-order kinetic models with the increase of PG content. However, the effect of PG on the phosphorus adsorption capacity of loess soil was most significant in the first 7 days. Na2SO4, NaH2PO4 and CaSO4 released from PG promoted the phosphorus adsorption capacity, while NaF inhibited the phosphorus adsorption capacity of loess soil. The present study shows that the phosphorus adsorption capacity of loess soil can be adjusted by PG dosage. Figures and Tables | References | Related Articles | Metrics

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Study on the influencing factors of dye transfer inhibition in cotton fabric washing Meng Mingzhu,Zhang Zhenzhen,Liang Shuaitong,Zhang Hongjuan,Wang Jiping 2022, 52 (6):  613-619.  doi: 10.3969/j.issn.1001-1803.2022.06.006 Abstract ( 215 )   HTML ( 26 )   PDF (1158KB) ( 176 )   Dye transfer in household washing has always been a problem that disturbs people. Herein, the influences of four factors including water hardness, water amount, washing temperature and Dye transfer inhibitor （DTI） on the transfer inhibition of Direct Blue 6 on cotton fabrics were studied. The response surface method （RSM） models of the 4 factors were built. All the RSM models show that water hardness is the most significant negative factor. Based on the DLVO theory, due to the presence of Ca2+ and Mg2+, the increase of water hardness can not only reduce the zeta potential of the fabric surface, but also cause the decrease of electrostatic repulsion between Direct Blue 6 and the fabric, and thus the dye won’t go off the fabric easily, that is, the dye is more likely to be adsorbed on the surface of the fabric. The increase of water amount can enhance the dye transfer inhibition effect. When the water amount increases, the initial mass concentration of dye is decreased, and the initial dynamic pressure of washing is increased, so that the dye flows through the fabric rapidly and the deposition on the fabric is reduced. The washing temperature also has a positive effect. When the washing temperature increases, the movement speed of dye molecules is increased, and the desorption rate is greater than the dyeing rate, so the dye molecules can shed from the fiber. Within the mass concentration range of 0.3 g/L DTI, only polyvinylpyrrolidone （PVP） and its cross-linked polymer have obvious inhibition effects on dye. Polymers have many hydrophilic groups and are easy to bind with direct dyes. However, pyridine-n-oxide （PNO） and lauryl betaine are small-molecule surfactants. Their structural differences make the RSM model show that polymers have better effects. The results of quantum chemical calculation also prove that the interactions between polymers and Direct Blue 6 are greater than the interactions between PNO and Direct Blue 6 or between lauryl betaine and Direct Blue 6. In addition, there is interplay between different washing factors. This work provides necessary basic information for the optimization of washing process for cotton fabrics and the modification of DTI. Figures and Tables | References | Related Articles | Metrics

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Experimental study on the effect of glycyrrhetinic acid on sebaceous gland of golden hamsters He Yifei,Lu Wangwang,Ma Shijing,Liu Guanting,Wang Mengping,Du Zhiyun 2022, 52 (6):  620-625.  doi: 10.3969/j.issn.1001-1803.2022.06.007 Abstract ( 242 )   HTML ( 20 )   PDF (1042KB) ( 182 )   This experiment preliminarily confirmed that glycyrtinic acid at the mass concentration of 50-100 μg/mL could significantly inhibit the secretion of triglyceride by 3T3-L1 cells （P<0.01） in a mass concentration-dependent manner. 3T3-L1 cells, as preadipocytes, continue to increase adipocyte proliferation and triglyceride accumulation under exogenous stimulation. They differentiate into mature adipocytes and form adipose tissue. Glycyrrhetinic acid can inhibit the proliferation of preadipocytes and reduce the accumulation of triglycerides, indicating that glycyrrhetinic acid has the effect of inhibiting lipid synthesis and metabolism at the cellular level. Further, through the golden hamsters model, it is confirmed that glycyrrhetic acid at the set mass concentration significantly reduces the area of bilateral sebaceous gland on the abdomen of golden hamsters, reduces the thickness and number of sebaceous glands, inhibites the growth of sebaceous glands and thus reduces the abnormal excessive secretion of sebaceous glands. At the mass concentration of 100 μg/mL, glycyrrhetinic acid significantly regulates the expression of SrebP-1C （P<0.001）, TG （P<0.01）, K6 （P<0.01）, K16 （P<0.01） and IL-6 （P<0.05） in sebaceous glands. It inhibits the SREBP protein activity in sebaceous gland tissue, inhibits sebum synthesis and secretion of triglyceride composition content, and further reduces the cutin formation and keratin K6, K16 expression in cells, which play a role in regulating sebaceous gland growth and oil secretion. Abnormal sebum secretion from sebaceous glands can induce skin health problems such as acne, skin barrier dysfunction and specific dermatitis. Through the above experimental studies, it has been preliminarily confirmed that the single use of glycyrrhetinic acid can effectively inhibit the growth of sebaceous gland spots in golden hamsters and reduce sebum secretion and inflammatory reaction. These results suggest that glycyrrhetinic acid may play a role in regulating oily skin, inhibiting acne, improving skin barrier function and specific dermatitis, and can be used as an active ingredient in skin surgery drugs and functional daily cosmetics that relieve acne and skin inflammation. Figures and Tables | References | Related Articles | Metrics

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The effect of donkey oil on the improvement of skin barrier function and its potential mechanism Fan Yumei,Tie Hang,Zhao Haiqing,Su Ning,Liao Feng 2022, 52 (6):  626-631.  doi: 10.3969/j.issn.1001-1803.2022.06.008 Abstract ( 503 )   HTML ( 23 )   PDF (1153KB) ( 181 )   The aim of the study was to explore the effect of donkey oil in enhancing the skin barrier function and its possible mechanism. Sodium lauryl sulfate was applied to the three-dimensional epidermal model （EpiKutis） to construct the skin barrier damage model, the tissue activity was detected by the MTT method and the level of IL-1α by the ELISA method. It was used to study the effect of the donkey oil on the barrier index and IL-1α level of the SLS-induced EpiKutis. RNA-seq technology was used to explain the physiological mechanism of donkey oil on the skin, and to reveal the possible mechanism of donkey oil to enhance the skin barrier function. The results show that donkey oil can significantly increase the barrier index of the SLS- EpiKutis model and reduce the level of IL-1α, and the effect is similar to that of dexamethasone. After the donkey oil acting on the EpiKutis model, 1 649 differentially expressed genes are screened, of which 619 genes are up-regulated and 1 030 genes are down-regulated. GO functional enrichment analysis shows that differentially expressed genes are related to epidermal development, epidermal cell differentiation and skin development. KEGG pathway enrichment analysis results show that differential genes are involved in TGF-β signaling pathway, IL-17 signaling pathway, HIF-1 signaling pathway, and cell factor-cytokine receptor interaction, NF-κB signaling pathway and other important biological pathways. The pathways related to donkey oil enhancing the skin barrier function may be TGF-β signaling pathway, HIF-1 signaling pathway and NF-κB signaling pathway. Figures and Tables | References | Related Articles | Metrics

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Effects of nicotinamide mixed with tea polyphenols on inhibiting melanin in PIG1 cells Fang Tinghuan,Jiang Qing,Tang Lirong 2022, 52 (6):  632-637.  doi: 10.3969/j.issn.1001-1803.2022.06.009 Abstract ( 625 )   HTML ( 50 )   PDF (1292KB) ( 240 )   The aim was to study and compare the effects of nicotinamide and its complexes with tea polyphenols on melanin biosynthesis and transport mechanism. Taking human skin melanocytes PIG1 cell line with high melanin expression induced by melanocyte-stimulating hormone （α-MSH） as the model, the effects of nicotinamide and its complexes matching with tea polyphenols on melanin content, intracellular tyrosinase activity and the key receptors in melanin biosynthesis and transport pathway were determined via western blot and colorimetric method with NaOH and L-DOPA. The results show that 2 g/L nicotinamide+0.5 g/L tea polyphenols, 3 g/L nicotinamide+0.3 mg/L tea polyphenols, 3 g/L nicotinamide+0.5 g/L tea polyphenols complexes show significantly inhibitory effects on melanin content, intracellular tyrosinase activity, the expression of tyrosinase-related protein-1 （TRP-1）, tyrosinase-related protein-2 （TRP-2）, melanocyte melanin cortisol receptor （MC1R） and human epidermal melanocyte transport-related proteins （Rab27a） protein in α-MSH-induced high melanin expression human PIG1 cell lines, which are stronger than that of 5 g/L nicotinamide. While 2 g/L nicotinamide only has the effects of suppressing intracellular tyrosinase activity. The combination of nicotinamide and tea polyphenols had more obvious effect to suppress the melanin biosynthesis and transport pathway in PIG1 cell lines. Figures and Tables | References | Related Articles | Metrics

Reviews

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Information bulletin analysis of EU RAPEX system and enlightenment to cosmetic ingredient management in China Huang Xianglu,Lu Jiacan,Xing Shuxia,Sun Lei 2022, 52 (6):  638-644.  doi: 10.3969/j.issn.1001-1803.2022.06.010 Abstract ( 248 )   HTML ( 17 )   PDF (972KB) ( 192 )   The aim was to analyze the cosmetic information bulletin of EU RAPEX, focusing on the analysis of products with chemical risks, and to provide reference for cosmetic ingredient management. The data from EU RAPEX system in 2005-2021 were summarized. The violations of the products were analyzed. According to the illegal substance, product type, country of origin and reason of violation, the notified results were analyzed statistically. Comparative analysis was made on the management of the notified substances according to the relevant information in European Union and China cosmetics ingredient management. At the same time, according to the whitening agent, preservative, flavor and fragrance, hair colorant, colorant, heavy metal, drug composition and other different categories of in-depth interpretation, its enlightenment was explored to the management of cosmetics raw materials in China. From February 2005 to May 2017, the REPEX system notifies 364 cosmetic products with chemical risk, involving 92 substances with violations. The most frequently reported violation is the addition of hydroquinone for skin-lightening products. Perfume is the most frequently reported product type. The main reason for violation is not as requiring to mark allergenic flavor fragrance. The most frequently reported country of origin is China, mainly because China does not have formulated management requirements for allergenic flavor fragrances, which leads to the labeling of flavor fragrances in China’s exported cosmetics does not meet the relevant requirements of the EU. The most frequently reported reasons for product violations are the detection or illegal addition of banned ingredients. Substances that need attention include whitening agents, preservatives, allergenic fragrances, hair colorants, colorants, heavy metal and pharmaceutical ingredients. Stronger post-marketing regulation of the related products is recommended for hydroquinone, Kathon and mercury. Strengthening or clarifying the requirements for raw material management such as kojic acid, allergenic flavor fragrances, and bimatoprost are needed. Increased training in the regulated use of preservatives and hair dyes should be implemented to establish technical standards for ingredients used in industries such as carbamazone and methylisothiazolinone that are more expensive and prone to violations. Risk monitoring is carried out for heavy metal starting materials （e.g., nickel, zirconium, antimony, chromium, cobalt, etc.）, and management measures are in place if necessary. Special attention should be paid to colorants CI 45161, CI 45174 and solvent yellow 172 in the new cosmetic ingredient registration filing work. With reference to the EU flexible notification and disposal mechanism, timely control measures should be taken on cosmetic ingredients with safety risks. Figures and Tables | References | Related Articles | Metrics

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Research progress in yeast metabolic engineering to produce natural product flavors Zhang Yongtao,Zhao Jingsha,Jiang Yanbing,Zhao Dan,Wang Changtao,Li Meng 2022, 52 (6):  645-655.  doi: 10.3969/j.issn.1001-1803.2022.06.011 Abstract ( 333 )   HTML ( 16 )   PDF (1185KB) ( 242 )   Natural product flavors, as additives for food, medicine and daily chemicals, have high market demand and have high development and utilization value. The extraction of fragrance products from animals and plants has the disadvantages of few sources, low content and difficulty in separation. Chemically synthesized fragrances also have potential safety hazards and pollution problems, and it is difficult to meet market demand. Therefore, the research and development of microorganisms that produce natural product fragrances to supplement or replace the original traditional extraction and chemical synthesis methods has important theoretical significance and potential application value. This article mainly summarizes the specific examples and research progress related to the metabolic modification of yeasts to produce terpenoids, aromatics and aliphatic fragrance compounds, including the host strains involved, key enzymes, metabolic pathways, modification strategies, and optimization of fermentation conditions. Yeasts, as a class of metabolically engineered strains, have a cell structure and a post-translational modification mechanism for expressing heterologous proteins that other microorganisms do not possess. Therefore, compared with other microorganisms, yeast can better express heterologous proteins and has greater potential as a chassis cell for the production of natural products. This article systematically summarizes the specific examples and research progress of yeast metabolic transformation to produce terpenoids, aromatics and aliphatic spices. It is found that the competition pathway and negative feedback regulation of the target product metabolism pathway, the tolerance of the chassis cells to the target product, the supply of the target product precursor compound and the difference in the selection of the substrate by the enzyme in the synthesis pathway are the biggest problems that limit the output of the product. Furthermore, relevant suggestions and prospects are put forward for the bottleneck problems faced by the use of metabolic engineering to transform microorganisms to synthesize natural product fragrance products, aiming to provide a reference for constructing chassis yeast cells for efficient production of fragrance products. Figures and Tables | References | Related Articles | Metrics

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Classification and application of surfactants in cleansing products Yang Xiufen 2022, 52 (6):  656-663.  doi: 10.3969/j.issn.1001-1803.2022.06.012 Abstract ( 948 )   HTML ( 44 )   PDF (1047KB) ( 631 )   Surfactants can play the roles of emulsification, foaming, detergency and thickening in cleansing products. Their dosages are usually 10%-15%. Surfactants are important raw materials of facial cleaning products, which have important influences on the performance of cleansing products, such as cleanliness, mildness and skin feeling experience. To adapt to the development trend of facial cleaning products, the application of surfactants has gradually changed from single chemical properties to diverse properties and greenness and environmental protection. Herein, based on the classification and application of surfactants for facial cleaning products, the development status, performance and application of different types of surfactants were explained and analyzed. Furthermore, the bottleneck problems and application challenges in the process of their development and evolution were summarized. Finally, the future development trend was prospected. This review might provide effective reference for the high-quality development of cleansing products. Figures and Tables | References | Related Articles | Metrics

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Advances of LSPR metal-catalyzed oxidation of alcohols to aldehydes and esters and their application in daily chemical field Wang Xiaoyu,Gao Xiaoxing,Wang Ruiyi,Niu Yulan 2022, 52 (6):  664-671.  doi: 10.3969/j.issn.1001-1803.2022.06.013 Abstract ( 251 )   HTML ( 12 )   PDF (1103KB) ( 143 )   Aldehydes and esters have been widely used as additives in daily chemicals due to the characteristics of sterilization, antisepsis and long-lasting aroma. The selective oxidation of alcohols to aldehydes and esters can achieve low-toxic, green and pollution-free synthetic routes. The LSPR metal catalysts are widely used as excellent catalysts for the oxidation of alcohols. Herein, the catalytic mechanism of LSPR metal-catalyzed oxidation of alcohols to aldehydes and esters are summarized, as well as the applications in the field of daily chemicals. The LSPR metals of Au, Ag and Cu are used as the active centers, which display high catalytic activity for the oxidation of alcohols, and the high selectivity to aldehydes and esters can also be obtained. In addition, the catalytic mechanism of LSPR metals under light conditions and the advances of photocatalytic selective oxidation of alcohols are reviewed based on the LSPR effects of the three metals, which can generate a large number of hot electrons on the surface of metals under light conditions. The oxidation of alcohols to aldehydes and esters can be promoted by the hot electrons. Besides, the reaction not only can be carried out under milder conditions, but also be more selective to the aldehydes and esters. In addition, the application of aldehydes and esters in daily chemical field are summarized. It is found that the aldehydes and esters prepared by the oxidation of alcohols as catalyzed by LSPR metals can achieve comparatively practical value in daily chemical field. Figures and Tables | References | Related Articles | Metrics

Analytical methods and testing

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An evaluation method for sterilization performance of fabric detergents Yang Jie,Yao Chenzhi,Yan Fang,Wang Jie,Li Xiaoting 2022, 52 (6):  672-676.  doi: 10.3969/j.issn.1001-1803.2022.06.014 Abstract ( 193 )   HTML ( 14 )   PDF (984KB) ( 150 )   Staphylococcus aureus was used as the test bacteria, and the 3 cm×3 cm JB-00 cotton cloth was used as the carrier. The staining carrier was prepared by inoculating 20 μL of the test bacteria suspension on each piece of cotton cloth by the 5-point method. 8 kinds of commercially available fabric detergents were used as the samples to be tested. Sterile hard water was used as the diluent to dilute the sample to be tested in a wide-mouth bottle to an effective concentration. 3 pieces of staining carrier were added to each wide-mouth bottle and washed for 20 minutes with magnetic stirring at 200 r/min, and then the water was changed and they were rinsed for 2 times and 5 min each time, which simulated the actual washing process of the fabric. Finally, the sterilization rate of different products was calculated by the plate counting method. The results show that the sterilization rate of samples A, G and H is above 95%, the sterilization rate of sample B is above 80%, the sterilization rate of samples C and E is above 60%, the sterilization rate of sample D is above 30%, and the sterilization rate of sample F is below 30%. This method can effectively distinguish the sterilization performance of different samples （P<0.05）; The stability of sterilization performance evaluated by this method is related to the level of the sterilization rate of the sample. For samples A, G and H that have good sterilization effects, the stability of sterilization rate is also high, while for samples D and F that have poor sterilization effects, the stability of sterilization rate is also low. Therefore, this method can be used as an evaluation method for the sterilization performance of fabric detergents. Figures and Tables | References | Related Articles | Metrics

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Rapid determination of antibacterial agents in skin care hyaluronic acid by high performance liquid chromatography-tandem mass spectrometry Zhang Junfang 2022, 52 (6):  677-682.  doi: 10.3969/j.issn.1001-1803.2022.06.015 Abstract ( 260 )   HTML ( 13 )   PDF (1272KB) ( 289 )   The aim was to establish a rapid method for the determination of antibiotics and nitroimidazoles in skin care hyaluronic acid by high performance liquid chromatography tandem mass spectrometry. Ten reagents for each of the two kinds of antibiotics were selected. After vortex oscillation, ultrasonic extraction, centrifugation and filtration, the mixed solution samples of the two kinds of antibiotics were prepared. They were separated by chromatographic column, ionized by electrospray ionization in positive ion mode and detected by multiple reaction monitoring mode under gradient elution. The results show that the total ions of 10 compounds contained in the solution samples of the two antibiotics have separation reactions at different times and produce corresponding response values, showing a good linear correlation. The correlation coefficient results are 0.997 and above 0.996, respectively. The detection limits and quantitative limits of the two antibiotics are 1.6, 6 mg/kg, 0.9-201 mg/kg and 5-401 mg/kg, respectively. The method can accurately and efficiently complete the rapid determination of antibiotics and nitroimidazoles in skin care hyaluronic acid. Figures and Tables | References | Related Articles | Metrics

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Microwave-assisted preparation of lactic acid carbon quantum dots and determination of p-nitroaniline with fluorescence quenching Wei Zengyun 2022, 52 (6):  683-688.  doi: 10.3969/j.issn.1001-1803.2022.06.016 Abstract ( 160 )   HTML ( 14 )   PDF (1248KB) ( 140 )   Carbon quantum dots （CDs） were prepared by one-step microwave method using lactic acid as carbon precursor and polyethylene glycol as a surface modifier. The structure and properties of the CDs were investigated by transmission electron microscopy, fluorescence and ultraviolet. The fluorescence quenching effect of 12 kinds of molecules to the quantum dots was studied. A new method for fluorescence analysis of p-nitroaniline quenching CDs is established. The linear relationship is good in the concentration range of 6×10-6-1×10-4 mol/L, and the limit of detection is 8.76×10-6 mol/L. The test for p-nitroaniline in hair dye pastes reveals that p-nitroaniline is contained in the three hair dyeing creams, which are 89.7 mg/g in chestnut brown, 129.2 mg/g in purplish red and 44.4 mg/g in flaxen. Figures and Tables | References | Related Articles | Metrics