CLAY CATALYZED SYNTHESIS OF BIO-DEGRADABLE POLY(GLYCOLIC ACID)

Glycolic acid was polymerized under vacuum in the presence and absence of nano sized clay.The added clay catalyzed the condensation polymerization which can be confirmed by recording FTIR spectroscopy and intrinsic viscosity (Ⅳ)values.The relative intensity of C=O/CH is increased while increasing the amount of clay.DSC showed the appearance of multiple endotherms of poly(glycolic acid).TGA showed the percentage weight residue remain above 750℃for polymer-nano composite system was 21% and hence proved the fl...

Clinical outcomes and 5-year follow-up results of keratosis pilaris treated by a high concentration of glycolic acid

BACKGROUND Keratosis pilaris is a hereditary abnormal keratosis of the hair follicle orifice.Gray-brown keratotic plugs in the pores and dark red keratotic papules at the openings of hair follicles can be seen,which contain coiled hair and are often accompanied by perifollicular erythema and pigmentation.Glycolic acid can correct the abnormalities of hair follicular duct keratosis and eliminate excessive accumulation of keratinocytes.It also promotes skin metabolism and accelerates the melanin metabolism.The therapeutic effect is related to the glycolic acid concentration.AIM To evaluate the efficacy and safety of a high concentration of glycolic acid in the treatment of keratosis pilaris,and to observe the outcomes at 5-year of follow-up.METHODS Twenty-five participants were recruited and areas with typical keratosis pilaris were selected as testing sites.High concentrations of glycolic acid(50%or 70%)were applied to a circular area(d=8 cm,S=50 cm2)and repeated four times,on days 0,20,40 and 60.Before each treatment and 20 d after the last treatment,on days 0,20,40,60,and 80 and at a 5-year follow-up,The number of follicular keratotic papules were counted and the extent of perifollicular erythema and pigmentation was determined.At the same time,the participants provided subjective evaluations of treatment efficacy and safety.RESULTS Treatment effectiveness was indicated by the percentage of keratotic papules in the test site,on days 20,40,60 and 80,which were 8%,12%,36%,and 60%,respectively.Compared with day 0,each difference was significant(P<0.05).Compared with day 0,differences in melanin content(M)in the skin and skin lightness(L)on days 40,60 and 80,the were statistically significant(P<0.05);skin hemoglobin content(E)on days 60 and 80 was statistically different as compared with before treatment(P<0.05).There were no significant differences in the number of keratotic papules,M,L,and E in 9 participants at the 5-year follow-up compared with before treatment(P>0.05%).CONCLUSION A high concentration of glycolic acid significantly improved skin roughness as well as follicular hyperpigmentation of patients with keratosis pilaris.The treatment was relatively safe,but there was no significant difference at the 5-year follow-up compared to before treatment.

Effect of Chitosan Coating on the Properties of Poly(glycolic acid-lactic acid)Thread-Embedding Material

Poly( glycolic acid-lactic acid)( PGLA) threadembedding material was modified by chitosan coating which could improve the rigidity,hydrophilicity and moisture absorption of the material,and produced better stimulation effect. Thus,this kind of thread-embedding materials which can be buried into acupuncture points to produce a long-time stimulation is popular in the acupuncture and moxibustion therapies. The variation tendencies of diameter,weight, hydrophilicity, and flexibility of the samples under the change of chitosan coating concentration,coating time and coating times were studied respectively. The results showed that the hydrophilicity,weight,and rigidity after coating rose in a certain range with the increase of coating time,coating times and coating concentration. The coating time had little influence on the diameter of fiber.

Study of Synthesis of Copoly (lactic acid/glycolic acid) by Direct Melt Polycondensation

A two steps direct copolymerisation process was developed. The first step is to produce oligomer and then the oligomer of lactic acid/glycolic acid (90/10) is polymerized with binary catalyst tin chloride dihydrate/p-toluenesulfonic acid. In this way, the direct synthesis of copoly (lactic acid/glycolic acid) without any organic solvent was investigated. The properties and structures of products were characterized by nuclear magnetic resonance (NMR), differential scanning calorimetry (DSC), X-ray diffraction and so on. The results show that comparatively high molecular weight copolymer of lactic acid and glycolic acid can be prepared by direct processing under appropriate technological conditions.

Electrocatalytic production of glycolic acid via oxalic acid reduction on titania debris supported on a TiO_(2)nanotube array

Electrodes prepared by anodic oxidation of Ti foils are robust and not toxic materials for the electrocatalytic reduction of oxalic acid to glycolic acid, allowing the development of a renewable energy-driven process for producing an alcoholic compound from an organic acid at low potential and room temperature. Coupled with the electrochemical synthesis of the oxalic acid from CO_(2),this process represents a new green and low-carbon path to produce added value chemicals from CO_(2). Various electrodes prepared by anodic oxidation of Ti foils were investigated. They were characterized by the presence of a TiO_(2) nanotube array together with the presence of small patches, debris, or TiO_(2) nanoparticles. The concentration of oxygen vacancies, the amount of Ti^(3+) measured by X-ray photoelectron spectroscopy(XPS) and the intensity of the anodic peak measured by cyclic voltammetry, were positively correlated with the achieved oxalic acid conversion and glycolic acid yield. The analysis of the results indicates the presence of small amorphous TiO_(2) nanoparticles(or surface patches or debris) interacting with TiO_(2) nanotubes, the sites responsible for the conversion of oxalic acid and glycolic acid yield. By varying this structural characteristic of the electrodes, it is possible to tune the glycolic acid to glyoxylic acid relative ratio. A best cumulative Faradaic efficiency(FE) of about 84% with FE to glycolic acid around 60% and oxalic conversion about 30% was observed.

Biodegradable Poly(butylene adipate-co-terephthalate)/Poly(glycolic acid) Films: Effect of Poly(glycolic acid) Crystal on Mechanical and Barrier Properties

Binary biodegradable polymers films, poly(butylene adipate-co-terephthalate)(PBAT) and poly(glycolic acid)(PGA), were prepared through batch melt mixing to obtain Film Ⅰ and Film Ⅱ under two different processing conditions. PGA crystals played a major role in enhancing the mechanical and barrier properties of the films. For Film Ⅰ, there were initial PGA crystals before the film blowing process, the PGA molecular chain further crystallized, forming the oriented crystallization of PGA. Moreover, the Xcand crystalline size in Film Ⅰ were higher than those in Film Ⅱ. Compared with the different processing methods, Film Ⅰ has excellent mechanical and oxygen barrier properties due to the crystallization and orientation. The tensile strength reached 45.0 MPa, and tear strength exceeded 138.2 kN/m, while the elongation at break was as high as 750% for PBAT/PGA 85/15 in Film Ⅰ. The WVTR, WVP coefficients, and OP coefficients of PBAT/PGA films were decreased obviously with increasing the PGA content both in Film Ⅰ and Film Ⅱ. Moreover, the barrier properties of oxygen in Film Ⅰ were better than that in Film Ⅱ. This work reveals a feasible processing technique by introducing of initial crystallization of PGA to blow PBAT/PGA films with excellent mechanical and barrier properties.

Improvement on the Mechanical Performance and Resistance Towards Hydrolysis of Poly(glycolic acid)via Solid-state Drawing

Poly(glycolic acid)is a biocompatible as well as biocomposable polymer with superior mechanical and barrier properties and,consequently,has found important applications in both medical and packaging fields.However,the high hydrolysis rate in a high humidity environment restricts its application.In this work,a solid-state drawing process after melt extrusion is applied in order to produce fibrous PGA with enhanced mechanical properties and a much better resistance towards hydrolysis.The crystal structure of PGA gradually transformed from spherulites into oriented fibrous crystals in the stretching direction upon solid-state drawing.Meanwhile,both the length of microfibril and the size of lamellae increased initially with the drawing ratio(DR),while the chain-folded lamellae transformed into extended-chain fibrils at high(er)DR.The oriented structures lead to an overall improvement of the mechanical properties of PGA,e.g.,the tensile strength increased from 62.0±1.4 MPa to 910±54 MPa and the elongation at break increased from around 7%to 50%.Meanwhile,the heat capacity of totally mobile amorphous PGA(∆C_(p)^(0)=0.64 J·g^(−1)·℃^(−1))was reported for the first time,which was used to analyze the content of mobile amorphous fraction(XMAF)and rigid amorphous fraction(XRAF).Both the oriented chain-folded lamellae crystals and the tightly arranged RAF are beneficial to prevent water molecules from penetrating the matrix,thus improving the resistance towards hydrolysis.As a consequence,the fibrous PGA with a DR of 5 showed a tensile strength retention rate of 17.3%higher in comparison with the undrawn sample after 7-days accelerated hydrolysis.Therefore,this work provides a feasible method to improve the mechanical and resistance towards hydrolysis performance of PGA,which may broaden its application and prolong the shelf-life of PGA products.

Generation of Tough Poly(glycolic acid)(PGA)/Poly(butylene succinate-co-butylene adipate)(PBSA)Films with High Gas Barrier Performance through In situ Nanofibrillation of PBSA under an Elongational Flow Field

Poly(glycolic acid)(PGA)is derived from glycolide obtained by fermenting pineapples or sugarcane,which has excellent gas barrier properties and a small carbon footprint.PGA is a potential substitute for the current aluminum-plastic composite films used in high barrier packaging applications.However,its poor ductility and narrow processing window limit its application in food packaging.Herein,poly(butylene succinate-co-butylene adipate)(PBSA)was used to fabricate PGA/PBSA blend films through an in situ fibrillation technique and blown film extrusion.Under the elongational flow field used during the extrusion process,a unique hierarchical structure based on the PBSA nanofibrils and interfacially oriented PGA crystals was obtained.This structure enhances the strength,ductility and gas barrier properties of the PGA/PBSA blend film.In addition,an epoxy chain extender(ADR4468)was used as a compatibilizer to further enhance the interfacial adhesion between PGA and PBSA.70PGA/0.7ADR exhibited a very low oxygen permeability(2.34×10^(-4)Barrer)with significantly high elongating at break(604.4%),tensile strength(47.4 MPa),and transparency,which were superior to those of petroleum-based polymers.Thus,the 70PGA/0.7ADR blown films could satisfy the requirements for most instant foods such as coffee,peanuts,and fresh meat.

Robust Poly(glycolic acid) Films with Crystal Orientation and Reinforcement of Chain Entanglement Network

The inherent brittleness of biodegradable poly(glycolic acid) (PGA) restricts its utilization in the packaging field. Traditional toughening methods usually require additional components accompanied by a sacrifice of strength. In the present work, PGA films with simultaneously enhanced strength and ductility are achieved via “casting-stretching-annealing” technology. The reinforced chain entanglement network of PGA induced by the intense extensional stress and the highly oriented crystals grown and refined during the stretching and annealing process endowed the improved ductility and strength of the PGA films, respectively. The relationships among the stretching process, microstructure and mechanical properties of the PGA films have been systematically investigated. As a result, the PGA film (SA-2) with low stretch ratios exhibits excellent ductility with an increase in elongation at break from 22% to 220% and tensile strength from 56 MPa to 130 MPa. Meanwhile, the PGA film (SA-4) with large stretch ratios features much higher tensile strength (335 MPa) while maintaining good ductility (elongation at break of 66%). In addition, highly oriented crystals result in obvious enhancement of heat resistance and dimensional stability of the PGA films. Therefore, this work provides an effective route to fabricate PGA films with both high strength and ductility which may promote the application of PGA materials.

Tailoring the Crystallization Behavior and Mechanical Property of Poly(glycolic acid) by Self-nucleation

Biocompostable poly(glycolic acid)(PGA)crystallizes slowly under fast cooling condition,leading to poor mechanical performance of the final products.In this work,a self-nucleation(SN)route was carried out to promote the crystallization of PGA by regulating only the thermal procedure without any extra nucleating agents.When self-nucleation temperature(Ts)decreased from 250℃ to 227℃,the nuclei density was increased,and the non-isothermal crystallization temperature(Tc)of PGA was increased from 156℃ to 197℃ and the half-life time(t0.5)of isothermal crystallization at 207℃ was decreased by 89%.Consequently,the tensile strength and the elongation at break of the PGA were increased by 12%and 189%,respectively.According to the change of Tc as a function of Ts,a three-stage temperature domain map(Domain I,II and III)was protracted and the viscoelastic behavior of the self-nucleation melt and the homogeneous melt was studied.The results indicated that interaction among PGA chains was remained in Domain IIb,which can act as pre-ordered structure to accelerate the overall crystallization rate.This work utilizes a simple and effective SN method to regulate the crystallization behavior and the mechanical properties of PGA,which may broaden the application range of resulting materials.

Bacterial cellulose/glycolic acid/glycerol composite membrane as a system to deliver glycolic acid for anti-aging treatment

Glycolic acid(GA),as an anti-aging skincare ingredient,plays a pivotal role in anti-aging treatment.However,its benefits could be overshadowed due to its side effects including skin burning and irritation when overused.Bacterial cellulose(BC)is a highly pure form of cellulose,biosynthesized in the form of a swollen membrane by several kinds of bacteria that was demonstrated to modulate the release of model drugs owing to its porous and 3D fibrous network structure,and glycerol(GL),as a plasticizer,could enhance the controlled drug delivery.Herein,we report a topical controlled drug delivery system based on BC membrane,GA and GL for controlling sustainable release of GA to reduce its side effects on the skin,while maintaining its prolonged and maximum therapeutic effect.The results showed that the incorporation of GL increased the malleability and flexibility of BC/GA/GL membrane,as compared with BC/GA membrane.In addition,the GL enhanced the control of the GA delivery,as evidenced by a higher swelling capacity and thereby a slower release of the GA from BC/GA/GL membrane.More importantly,in vitro study indicated that both BC/GA and BC/GA/GL membranes could effectively stimulate endogenous collagen synthesis in NIH3T3 cells owing to the release of GA,and that BC/GA/GL membrane is more conducive to a long-term cell adhesion,spreading,and proliferation of NIH3T3 and HaCaT cells due to its lower and sustainable release of GA than BC/GA membrane.This study suggests the BC/GL/GA composite membrane holds great promise as an appealing platform to control the release of GA to greatly promote renewal of skin cells for effective anti-aging treatment.

Synthesis and Hydrophilic Performance of Poly(Lactic Acid)-Poly(Ethylene Glycol) Block Copolymers

Lactide was synthesized using lactic acid and stannous octoate as raw material and catalyst, respectively. Poly(lactic acid)-poly(ethylene glycol) (PLA-PEG) was prepared by lactide and poly (ethylene glycol) (PEG) via ring-opening polymerization. The most appropriate technological conditions of synthesis of lactide were researched in the paper. The copolymers were measured by Infrared spectroscopy (IR) and 1H nuclear magnetic resonance (1H NMR). The results proved that the lactide and PLA-PEG were synthesized successfully. Hydrophilic performance of the copolymer was measured by a water contact angle tester after prepared into a flat membrane. The water contact angle changed from 81.5? to 71.6?, which proved that the hydrophily of PLA-PEG was better than PLA.

Biological conduits combining bone marrow mesenchymal stem cells and extracellular matrix to treat long-segment sciatic nerve defects

The transplantation of polylactic glycolic acid conduits combining bone marrow mesenchymal stem cells and extracellular matrix gel for the repair of sciatic nerve injury is effective in some respects, but few data comparing the biomechanical factors related to the sciatic nerve are available. In the present study, rabbit models of 10-mm sciatic nerve defects were prepared. The rabbit models were repaired with autologous nerve, a polylactic glycolic acid conduit ＋ bone marrow mesenchymal stem cells, or a polylactic glycolic acid conduit ＋ bone marrow mesenchymal stem cells ＋ extracellular matrix gel. After 24 weeks, mechanical testing was performed to determine the stress relaxation and creep parameters. Following sciatic nerve injury, the magnitudes of the stress decrease and strain increase at 7,200 seconds were largest in the polylactic glycolic acid conduit ＋ bone marrow mesenchymal stem cells ＋ extracellular matrix gel group, followed by the polylactic glycolic acid conduit ＋ bone marrow mesenchymal stem cells group, and then the autologous nerve group. Hematoxylin-eosin staining demonstrated that compared with the polylactic glycolic acid conduit ＋ bone marrow mesenchymal stem cells group and the autologous nerve group, a more complete sciatic nerve regeneration was found, including good myelination, regularly arranged nerve fibers, and a completely degraded and resorbed conduit, in the polylactic glycolic acid conduit ＋ bone marrow mesenchymal stem cells ＋ extracellular matrix gel group. These results indicate that bridging 10-mm conduit ＋ bone marrow mesenchymal stem sciatic nerve defects with a polylactic glycolic acid cells ＋ extracellular matrix gel construct increases the stress relaxation under a constant strain, reducing anastomotic tension. Large elongations under a constant physiological load can limit the anastomotic opening and shift, which is beneficial for the regeneration and functional reconstruction of sciatic nerve. Better regeneration was found with the polylactic glycolic acid conduit ＋ bone marrow mesenchymal stem cells ＋ extracellular matrix gel grafts than with the polylactic glycolic acid conduit ＋ bone marrow mesenchymal stem cells grafts and the autologous nerve grafts.

A novel bioactive nerve conduit for the repair of peripheral nerve injury

The use of a nerve conduit provides an opportunity to regulate cytokines,growth factors and neurotrophins in peripheral nerve regeneration and avoid autograft defects.We constructed a poly-D-L-lactide(PDLLA)-based nerve conduit that was modified using poly{(lactic acid)-co-[(glycolic acid)-alt-(L-lysine)]}andβ-tricalcium phosphate.The effectiveness of this bioactive PDLLA-based nerve conduit was compared to that of PDLLA-only conduit in the nerve regeneration following a 10-mm sciatic nerve injury in rats.We observed the nerve morphology in the early period of regeneration,35 days post injury,using hematoxylin-eosin and methylene blue staining.Compared with the PDLLA conduit,the nerve fibers in the PDLLA-based bioactive nerve conduit were thicker and more regular in size.Muscle fibers in the soleus muscle had greater diameters in the PDLLA bioactive group than in the PDLLA only group.The PDLLA-based bioactive nerve conduit is a promising strategy for repair after sciatic nerve injury.

Oxidation of glycerol with H_2O_2 on Pb-promoted Pd/γ-Al_2O_3 catalysts

A series of bimetallic Pd-Pb catalysts with a constant Pd content of 1 wt%and Pb/Pd atomic ratio from 0 to 1.6 supported on γ-Al2O3 were prepared and used for glycerol oxidation with H2O2 as the oxidizing agent at atmospheric pressure,45℃ and pH =11.The morphology and dispersion of the catalysts were characterized by scanning electron microscopy-energy dispersive X-ray spectroscopy（SEM-EDX） and transmission electron microscopy（TEM）.The presence of an alloy phase in the bimetallic catalyst was detected by X-ray photoelectron spectroscopy（XPS）.Glycerol conversion obtained with the monometallic Pd catalyst was 19%,which was increased to 100%with the addition of Pb.The four bimetallic PdPb catalysts were able to oxidize glycerol to dihydroxyacetone（DIHA） and the selectivity to DIHA reached 59%,58%,34%and 25%for PdPb0.25,PdPb0.50,PdPb1.00 and PdPbl.60 catalysts,respectively.

Evaluation of Two Highly Porous Microcrystalline Biphasic Calcium Phosphate-Based Bone Grafts for Bone Regeneration: An Experimental Study in Rabbits

A biphasic bone grafting biomaterial based on a mixture of calcium phosphates and beta-tricalcium phosphate (β-TCP) phases with high nanoporosity was synthesized. The synthesis route was based on calcium phosphate composition and the incorporation of glycolic acid as a pore former, giving a material composed of 97% β-TCP and 3% calcium orthophosphates (CaPO4). An in vitro study of the purity, microstructure, crystalline domain, and pores size for the material obtained was performed by SEM analysis as well as full structural characterization. The region of interest related to the surface was determined by the specific surface area measured with the BET method. In vivo evaluation of bone response was performed by implanting the new low-cost biphasic manufacturing material synthesized in this work, which was compared with a biphasic material of similar chemical and microstructural composition existing in the commercial market and with higher cost called Synergy Odontit® β-TCP. The materials were implanted separately into 5 mm diameter defects in the tibias of New Zealand White rabbits at 30, 60, and 90 days. The results obtained showed that the host tissue well accepted the new biphasic material;the presence of new bone formation was observed. A more complete resorption was observed for the new microcrystalline biphasic material compared to for a commercial β-TCP material.

Altered serous levels of monoamine neurotransmitter metabolites in patients with refractory and non-refractory depression

The study examined plasma metabolite changes of monoamine neurotransmitters in patients with treatment-resistant depression （TRD） and non-TRD before and after therapy. All 30 TRD and 30 non-TRD patients met the diagnostic criteria for a depressive episode in accordance with the International Classification of Diseases, Tenth Revision. Before treatment, and at 4, 6, and 8 weeks after treatment, the plasma metabolite products of monoamine neurotransmitters in TRD group, including 5-hydroxyindoleacetic acid, 3-methoxy-4-hydroxyphenyl ethylene glycol and homovanillic acid, were significantly lower than those in the non-TRD group. After two types of anti-depressive therapy with 5-serotonin and norepinephrine reuptake inhibitor, combined with psychotherapy, the Hamilton Depression Rating Scale scores were significantly reduced in both groups of patients, and the serous levels of 5-hydroxyindoleacetic acid and 3-methoxy-4-hydroxyphenyl ethylene glycol were significantly increased. In contrast, the homovanillic acid level exhibited no significant change. The levels of plasma metabolite products of peripheral monoamine neurotransmitters in depressive patients may predict the degree of depression and the therapeutic effects of treatment.

Non-viral liposome-mediated transfer of brain-derived neurotrophic factor across the blood-brain barrier

Brain-derived neurotrophic factor（BDNF） plays an important role in the repair of central nervous system injury,but cannot directly traverse the blood-brain barrier.Liposomes are a new type of non-viral vector,able to carry macromolecules across the blood-brain barrier and into the brain.Here,we investigate whether BDNF could be transported across the blood-brain barrier by tail-vein injection of liposomes conjugated to transferrin（Tf） and polyethylene glycol（PEG）,and carrying BDNF modified with cytomegalovirus promoter（pC MV） or glial fibrillary acidic protein promoter（p GFAP）（Tf-p CMV-BDNF-PEG and Tf-p GFAP-BDNF-PEG,respectively）.Both liposomes were able to traverse the blood-brain barrier,and BDNF was mainly expressed in the cerebral cortex.BDNF expression in the cerebral cortex was higher in the Tf-p GFAP-BDNF-PEG group than in the Tf-p CMV-BDNF-PEG group.This study demonstrates the successful construction of a non-virus targeted liposome,Tf-p GFAP-BDNF-PEG,which crosses the blood-brain barrier and is distributed in the cerebral cortex.Our work provides an experimental basis for BDNF-related targeted drug delivery in the brain.

Biotransformation of ethylene glycol by engineered Escherichia coli

There has been extensive research on the biological recycling of PET waste to address the issue of plastic waste pollution,with ethylene glycol(EG)being one of the main components recovered from this process.Therefore,finding ways to convert PET monomer EG into high-value products is crucial for effective PET waste recycling.In this study,we successfully engineered Escherichia coli to utilize EG and produce glycolic acid(GA),expecting to facilitate the biological recycling of PET waste.The engineered E.coli,able to utilize 10 g/L EG to produce 1.38 g/L GA within 96 h,was initially constructed.Subsequently,strategies based on overexpression of key enzymes and knock-out of the competing pathways are employed to enhance EG utilization along with GA biosynthesis.An engineered E.coli,characterized by the highest GA production titer and substrate conversion rate,was obtained.The GA titer increased to 5.1 g/L with a yield of 0.75 g/g EG,which is the highest level in the shake flake experiments.Transcriptional level analysis and metabolomic analysis were then conducted,revealing that overexpression of key enzymes and knock-out of the competing pathways improved the metabolic flow in the EG utilization.The improved metabolic flow also leads to accelerated synthesis and metabolism of amino acids.

Determination of Glycolate Acid, Mono- and Dichloroacetic Acids in Synthetical Betaine by Anion-exchange Chromatography

An anion-exchange chromatography method combined solid phase extraction （SPE） was developed for the simultaneous analysis of glycolate acid （GL）, monochloroacetic acid （MCA） and dichloroacetic acid （DCA） in synthetical betaine products. The analytes and unknown anionic impurities were well separated on a Metrosep A supp5 anion-exchange column （150 mm×4 mm） with 2.0 mmol/L Na2CO3＋2.0 mmol/L NaHCO3 solution as eluent. Suppressed conductivity detection was used. A strong cation exchange （SCX） solid phase extraction （SPE） cartridge was used to reduce the concentration of matrix betaine and a Cleanert IC-Ag pretreatment cartridge was used to remove high Cl- concentration. The detection limits of GL, MCA and DCA were 0.09, 0.017 and 0.05 μg/L, respectively. The relative standard deviations （RSDs） of the retention times and peak areas were less than 0.09% and 0.49%, respectively. The recoveries of the three analytes were between 90.6% and 100.8%. The analytical results showed that GL and DCA were present in high concentration and no MCA was found when the proposed ion chromatography method was applied to three synthetical betaine samples. The proposed method is simple, sensitive and timesaving, and is also suitable for routine analysis in quality control of synthetical betaine products.