Table of Content

22 August 2018, Volume 48 Issue 8 Previous Issue    Next Issue

Basic research

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Interfacial dilational rheological behavior of (1-butyl-3- methylimidazolium)-based surfactant ionic liquids HOU Zhao-wei,ZHANG Fu-ling,WU Xiao-lin,SUN Ji-chao,ZHENG Li-qiang 2018, 48 (8):  423-429.  doi: 10.13218/j.cnki.csdc.2018.08.001 Abstract ( 266 )   PDF (5116KB) ( 253 )   The dynamic interfacial tension and dilational properties of 1-butyl-3-methylimidazolium dodecyl sulfate ([bmim][DS]) and 1-butyl-3-methylimidazolium di(2-ethylhexyl) sulfosuccinate ([bmim][AOT]) at n-heptane/water interface were studied.The dilational elasticity of [bmim][DS] or [bmim][AOT] was compared with traditional surfactants (SDS or Na[AOT]).The influence of electrostatic interaction of 1-butyl-3-methylimidazolium cations on the properties of interfacial film was investigated.In addition,by comparing the dilational elasticity at different concentrations of [bmim][DS] and [bmim][AOT],we verified the effects of the change in the number of alkyl chains on the interfacial dilational rheological behavior. References | Related Articles | Metrics

Development and application

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Study on exfoliation of hydrotalcite-like compounds in aqueous phase with imidazoline amphoteric surfactants SUN Hui-yan,BAI Xue-li,XUE Dan-dan,HUANG Xin,ZHANG Jian,ZHANG Yue 2018, 48 (8):  430-433.  doi: 10.13218/j.cnki.csdc.2018.08.002 Abstract ( 271 )   PDF (6286KB) ( 249 )   Imidazoline amphoteric surfactants intercalated MgAl-hydrotalcite-like compounds (MgAl-LDHs) were prepared by co-precipitation method.After placing the MgAl-LDHs in an aqueous solution with pH=2,the amphoteric ions present in the interlayer were converted to cationic,then the exfoliation of MgAl-LDHs layers was successfully achieved in the aqueous phase by electrostatic repulsion.The samples were characterized by X-ray diffraction,fourier transform infrared spectroscopy,thermogravimetry,differential scanning calorimetry,and transmission electron microscopy.The results show that imidazoline amphoteric surfactants with different molecular lengths are successfully embedded between the MgAl-LDHs layers,and the interlayer spacing is different.The intercalated MgAl-LDHs are successfully exfoliated.The results of XRD and TEM have confirmed the stratification of MgAl-LDHs,while the Tyndall effect has confirmed the presence of colloids. References | Related Articles | Metrics

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Design and evaluation of functional material for triclosan via molecular recognition and molecular imprinting technology FAN Wei-gang,JIANG Ying-fang,ZHANG Ya-gang,WANG Lu-lu,ZHANG Le-tao,YASIN Akram 2018, 48 (8):  434-438.  doi: 10.13218/j.cnki.csdc.2018.08.003 Abstract ( 230 )   The working mechanism of molecularly imprinted polymers (MIPs) for triclosan (TCS) is based on acid-base interaction.The designed MIPs were prepared by thermal bulk polymerization using DMAEMA,DEAM,hydrochloride of AMA,4-VP and MAA as functional monomers,EGDMA and DVB as cross-linkers,AIBN as initiator and acetonitrile as solvent.Adsorption study shows that the MIPs made with DEAM achieve highest adsorption percentage of 78.5% and imprinting factor of 1.7.The selective binding experiments show that DEAM-MIPs show high selectivity to TCS over other structural analogues.Adsorption experiments on TCS by MIPs show that after 5 times of recovery,the adsorption capacity only drops by 5.1%,indicating that the MIPs can be reused multiple times. References | Related Articles | Metrics

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Preparation and characterization of alkyl-modified silicone elastomer microspheres LV Xi-ming,YANG Cheng 2018, 48 (8):  439-443.  doi: 10.13218/j.cnki.csdc.2018.08.004 Abstract ( 418 )   PDF (5073KB) ( 274 )   Alkyl-modified polymethylhydrosiloxane (R-PMHS) with different percent grafting of alkyls was prepared by hydrosilylation of 1-dodecene and polymethylhydrosiloxane (PMHS).The alkyl-modified silicone elastomer microspheres were prepared by Pickering emulsion polymerization with R-PMHS and vinyl-terminated polydimethylsiloxane (Vi-PDMS) as oil phase and the hydrophilic nano-SiO2 particles and a small amount of cetyltrimethylammonium bromide (CTAB) as emulsifiers.The results show that the most stable emulsion together with the best morphology of microspheres were obtained when the concentration of CTAB is 2×10-4 mol/L,the mass ratio of oil to water is 1∶1,the mass fraction of nano-SiO2 to oil phase is 4% and the molar ratio of silicon-hydrogen bond (Si-H) to vinyl is 2∶1.The oil absorption results show that the lipophilicity of these silicone elastomer microspheres increases with the increase of percent grafting of alkyls. References | Related Articles | Metrics

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Study on the effect of different medium solutions on the stability of Vitamin C CHEN Hui-fang,JIANG Xin-yuan,CHEN Jie-nan,XU Qiong-wen,MENG Hao-liang 2018, 48 (8):  444-449.  doi: 10.13218/j.cnki.csdc.2018.08.005 Abstract ( 448 )   PDF (4418KB) ( 282 )   The stability of Vitamin C in different medium solutions such as inorganic salts,sodium carboxymethyl cellulose, β-cyclodextrin and polyethylene glycol was studied by ultraviolet spectrophotometry,and the mechanism of the above mediums retarded the oxidation of Vitamin C was also explored.The results show that magnesium chloride,potassium chloride,sodium chloride and sodium carboxymethyl cellulose can significantly improve the stability of Vitamin C.While the sodium carboxymethyl cellulose is safe,less dosage and has significant effect to protect Vitamin C,it can be widely used in cosmetics,food,medicine and other fields to protect the stability of Vitamin C.The amount of initial dissolved oxygen content in the mixed solution of polyethylene glycol, β-cyclodextrin and Vitamin C is similar to that of the blank Vitamin C solution,and it significantly decreases with time.However,the amount of initial dissolved oxygen content in the mixed solution of sodium chloride,carboxymethyl cellulose and Vitamin C is much lower than that of the blank Vitamin C solution and it decreases very slowly with time.These phenomena are consistent with the protective effect of the above medium solutions on Vitamin C.The level of initial dissolved oxygen content in the medium solutions and the speed of decline affect the stability of Vitamin C.The type and concentration of inorganic salt ions affect the amount of dissolved oxygen content in the solution,while the solution viscosity has the effect on the dissolved oxygen content in water-soluble polymer solutions such as sodium carboxymethyl cellulose,polyethylene glycol and β-cyclodextrin. References | Related Articles | Metrics

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Study on skincare efficacy of compound extract from Chinese herbal medicines LIU Fang,XU Yong-wei,WANG Shan-shan,GONG Sheng-zhao 2018, 48 (8):  450-456.  doi: 10.13218/j.cnki.csdc.2018.08.006 Abstract ( 612 )   PDF (5646KB) ( 323 )   A combination of in vitro experiments and human efficacy evaluation were used to assess the whitening,anti-aging and anti-allergic soothing efficacy and the irritation of a compound extract which was obtained from 5 kinds of Chinese herbal medicines.The results show that the compound extract is classified as non-irritation substance.Besides,it has strong ability to inhibit tyrosinase activity,scavenge DPPH/hydroxyl/superoxide anion radicals and inhibit hyaluronidase activity.After 4 weeks of using the emulsion containing the compound extract,it can significantly reduce skin melanin content and decrease the scores of skin UV spots,chloasma,wrinkle and texture.In addition,this emulsion containing the compound extract can effectively relieve the tingling caused by lactic acid.The above results indicate that this compound extract is a safe and effective cosmetics raw material which has good whitening,anti-aging and anti-allergic soothing efficacy. References | Related Articles | Metrics

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Preparation and study of oral sustained-release formulation with long-acting bacteriostasis CHEN Wei-cai,YI Dan,LI Shu-yu,ZHANG Li-ping,JIANG Qing 2018, 48 (8):  457-461.  doi: 10.13218/j.cnki.csdc.2018.08.007 Abstract ( 309 )   PDF (3554KB) ( 271 )   By measuring the minimal inhibitory concentration (MIC) of various antibacterial drugs commonly used in toothpaste,it is found that both cetylpyridinium chloride (CPC) and chlorhexidine have strong bacteriostatic effect on Streptococcus mutans and Porphyromonas gingivalis with the MIC below 1 mg/L.The CPC was coated with triacetyl-β-cyclodextrin (TA-CD) and ethyl cellulose (EC) and particles were prepared by spray drying.The drug-loaded particles had obvious “burst release” phenomenon,and it showed better sustained release effect after adding stearic acid (SA).In addition,the adhesion rate of the drug-loaded particles can be significantly improved after brushing,when certain amount of polyvinyl alcohol (PVA) was added.When the mass fraction of PVA is 20%,the adhesion rate of the drug-loaded particles is the highest,reaching 19.1%.The mixed bacterium biofilm was used to evaluate the bacteriostasis of drug-loaded particle (DLP-7) and CPC.The results show that the relative inhibition rate of drug-loaded particles increases continuously over time.After 4 h,the relative inhibition rate of DLP-7 is higher than CPC,which means that DLP-7 shows long-acting bacteriostasis. References | Related Articles | Metrics

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Study on the development and efficacy of oleuropein toothpaste LIU Qing-gang 2018, 48 (8):  462-465.  doi: 10.13218/j.cnki.csdc.2018.08.008 Abstract ( 288 )   PDF (2802KB) ( 255 )   Through the experimental study of oleuropein in different toothpaste formulations,the optimal application scheme was determined.The content of oleuropein in toothpaste was investigated by high temperature stability test.The in vitro bacteriostasis experiment and clinical trial results prove that the toothpaste containing a certain amount of oleuropein has good bacteriostasis effect.And the pharmacological and toxicological effects of the toothpaste containing oleuropein were studied. References | Related Articles | Metrics

Analytical methods and testing

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Evaluation of uncertainty in the determination of benzalkonium chloride in cosmetics by HPLC WANG Tao,LI Zhuo,JIA Han-bing,SUN Xiao,TIAN Ren-fang,XUN Ying 2018, 48 (8):  466-471.  doi: 10.13218/j.cnki.csdc.2018.08.009 Abstract ( 363 )   PDF (4169KB) ( 287 )   Uncertainties from the determination procedure of three substances of benzalkonium chloride (dodecyldimethylbenzylammonium chloride (C12),tetradecyldimethylbenzylammonium chloride (C14) and hexadecyldimethylbenzylammonium chloride (C16) in Safety and Technical Standards for Cosmetics (2015 Edition) by high performance liquid chromatography (HPLC) were assessed.The mathematical model was established,and the source of uncertainty was investigated and quantified.The combined standard uncertainty and expanded uncertainty were calculated.The results show that the expanded uncertainties are 0.027%,0.029% and 0.006% (95% confidence level,k=2) when the mass fraction of benzalkonium chloride (C12,C14 and C16 ) in cosmetics are 0.045%,0.048% and 0.010%,respectively.The main sources of the uncertainty are analyzed,and improved method is introduced. References | Related Articles | Metrics

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Determination of 24 allergens in perfume with high performance liquid chromatography tandem mass spectrometry WANG Yu-jian,LIANG Zhen-gang,FU Ling-mei,DONG Cun-zhu 2018, 48 (8):  472-477.  doi: 10.13218/j.cnki.csdc.2018.08.010 Abstract ( 320 )   PDF (4399KB) ( 264 )   A method of simultaneous determination of 24 allergens in perfume was established with high performance liquid chromatography tandem mass spectrometry.The target compounds were extracted with acetonitrile and determined with HPLC-MS/MS (MRM mode,ESI) with external standard method.The results show that,good linear relationship between concentration and peak area ratio is obtained in the range of 1.0~5.0 mg/L for the 24 allergens.The instrument detection limit is 1.0 mg/L and the method detection limit is 5.0 mg/kg.The limit of quantitation (LOQ) is 15.0 mg/kg.The average recoveries of 24 allergens are 85.9%~110.0% at spiked levels of 5,10 and 20 mg/kg with relative standard derivations (RSDs) of 5.5%~12.0% (n=10). References | Related Articles | Metrics

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Determination of chloroacetaldehyde and glutaral in cosmetics by pre-column derivatization-high performance liquid chromatography LIN Wen-jin,XUN Zhi-qing,HUANG Jin-feng,GUO Xin-dong,LUO Xiao-yin,YE Jia-rong 2018, 48 (8):  478-482.  doi: 10.13218/j.cnki.csdc.2018.08.011 Abstract ( 395 )   PDF (3346KB) ( 255 )   A pre-column derivatization-high performance liquid chromatography (HPLC) method was established for the determination of chloroacetaldehyde and glutaral in cosmetics.The samples were extracted with 50% acetonitrile solution (in volume ratio),derivatized with 2,4-dinitrophenylhydrazine,separated by RRHD C18 column (2.1 mm×50 mm,1.7 μm) and detected by HPLC-diode array detector.The retention time and UV absorption spectra were adopted for qualitative and an external standard method was used to quantify.Under the optimal conditions,the results show that chloroacetaldehyde and glutaral have good linear relationship in the range of 0.05-5.0 mg/L with the correlation coefficients greater than 0.999 4.The detection limit and quantification limit of the method are 1.0 and 3.0 mg/kg,respectively.The recoveries of spiked samples are ranged from 89.5% to 106.1% and the relative standard deviations (RSDs,n=6) are between 1.9% and 6.6%.The method is suitable for the determination of chloroacetaldehyde and glutaral in cosmetics. References | Related Articles | Metrics