ABSTRACT
OBJECTIVE：To establish the method for content determination of 17 kinds of amino acids in Sargassum and its adulterants，and to carry out cluster analysis ，so as to provide reference for quality control of Sargassum. METHODS ：Totally of 18 batches of sample （S1-S6 as certified product ，S7-S18 as adulterants ）were collected. After acid hydrolysis ，amino acids contents were detected by using automatic amino acid analyzer. The separation was performed on LCAK 06/Na sulfonic acid cation exchange resin column with mobile phase consisted of buffer-regeneration system （gradient elution ）at the flow rate of 0.45 mL/min （elution pump ）and 0.25 mL/min（derivative pump ）. The detection wavelengths were set at 440 nm（proline）and 570 nm（other amino acids ），and the sample size volume was 50 μL. PASW Statistics 18.0 software was used ，and cluster analysis was conducted by using group connection method of cluster analysis with “square Euclidean distance ”as the measurement standard. RESULTS ：17 kinds of amino acids were well separated without interference from blank sample. The linear relationship between mass concentration and peak area was good （all r were over 0.998），and the upper and lower limits of the linear range were 48.06 μg/L （cystine）and 1.501 μg/L（glycine），respectively；RSDs of precision ，reproducibility and stability tests were lower than 2％. The average recoveries were between 90.60％-101.56％（RSDs were 0.88％-2.15％，n＝6）. 17 kinds of amino acids were detected in Sargassum and its adulterants ，among which the contents of glutamic acid ，aspartic acid ，leucine，alanine，glycine and valine were relatively high . Results of cluster analysis showed that 18 batches of sample were clustered into 4 categories，i.e. S 1-S6 into one category；S7-S9 into one category ；S10-S12，S16-S18 into one category ；S13-S15 into one category ；which was consistent with the identification result of Sargassum and its adulterants . CONCLUSIONS ：The method is simple ， rapid， accurate and reproducible，and can be used for the quantitative analysis and identification of amino acids in Sargassum and adulterants.
ABSTRACT
The determination methods for the related substances and contents of aminoglycosides were reviewed. The HPLC-ELSD, HPLC-PAD and the other methods for the determination of aminoglycosides in Chinese Pharmacopoeia, USP and European Pharmacopoeia were introduced. The utilization specialties of the post column derivatization in detecting aminoglycosides were also in-troduced. Finally, the above three methods were compared, and the development of analytical methods for aminoglycosides was out-looked.
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OBJECTIVE:To establish a method of contents determination of 17 amino acids in Fritillariae Pallidiflorae Bulbus produced in Xinjiang. METHODS:Cation-exchange column was used to separate 17 kinds of amino acids;post-column derivatiza-tion liquid chromatography was used to determine the contents of amino acids:the column was strong sulfonic acid cation exchange resin LCAK06/Na with mobile phase A(weighing trisodium citrate 11.9 g,citric acid 6 g,phenol 1 g,dissolving by water,then adding 65 mL of methanol and 6 mL of concentrated hydrochloric acid,bringing the volume with tap water,adjusting pH to 3.4), mobile phase B(weighing trisodium citrate 11.9 g,NaOH 2.8 g,phenol 1 g,boric acid 5.0 g,adding water to dissolve,adjustingpH to 10.8),gradient elution,flow rate was 0.45 mL/min for A pump and 0.25 mL/min for M pump,the detection wavelength was 440 nm for proline and 570 nm for the remaining amino acids,the injection volume was 50 μL. RESULTS:The linear range were 20~400 nmol/mL of aspartic acid,threonine,serine,glutamic acid,glycine,alanine,valine,methionine,isoleucine,leucine,ty-rosine,phenylalanine,histidine,lysine,arginine,proline,10-200 nmol/mL of cystine(r were higher than 0.9890);RSDs of preci-sion,stability and reproducibility tests were lower than 2.0%;limits of detection were 0.16 nmol/mL except for cystine(0.08 nmol/mL);recovery was 98.5%-99.5%(RSD was 0.06%-0.21%,n=6). CONCLUSIONS:The method is simple with good precision, stability and reproducibility,and can be used for the simultaneous determination of amino acids in Fritillariae Pallidiflorae Bulbus produced in Xinjiang.
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Objective:To establish an HPLC coupled with post column derivatization method for the determination of gentamicin C components and the related substances based on the latest European Pharmacopeia and compare with the electrochemical method. Methods:A Hydrophilic C18(250 mm ×4.6 mm, 5 μm)column was used with acetonitrile-50 mmol·L-1 sodium hydroxide solution ( pH 2. 6) containing 0. 7% trifluoroacetic acid and 0. 025% pentafluoropropanoic acid (1. 5∶98. 5) as the mobile phase. The temper-ature of post-column reaction was set at 30℃, and the samples were detected by a fluorescence detector withλex of 340nm andλem of 430nm. A pulsed amperometric detector (PAD) was applied in the electrochemical method with golden working electrode in a four-po-tential working mode. Results: According to the results of the two detection methods, the linear range of C1a , C2 , C2a and C1 was 5.82-233.00,6.92-277.00,4.00-160.00and6.23-249.00 μg·ml-1(r >0.9993) , respectively. The limit of detection and quantization were 0. 92-3. 28ng and 1. 37-5. 19ng, respectively. Conclusion:There is no significant difference between the determina-tion results of the two methods.
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AIM:To study a method for the determination of 13 N-methylcarbamate peticides in traditional Chinese herbal medicines(TCHMs).METHODS:Thirteen pesticides were extracted by acetonitrile,and purified through solid phase extraction(SPE)cartridges,then detected by HPLC with post-column derivatization and Fluorescense Detector excited wavelength was 330 nm,emissive wavelength was 465 nm.RESULTS:The analytical performance was demonstrated by the analysis of 6 TCHMs samples' extracts,spiked at three concentration levels for each pesticide.In general,the recoveries ranging from 74.1 to 108.8%,with relative standard deviations(RSDs)better than 15%,were obtained.The limit of quantification(LOD)of 13 pesticides from 0.000 3 to 0.06 mg/kg.CONCLUSION:The method has good extraction efficiency and purification effect,which could be standard of N-methylcarbamate peticides residues in the routine analysis of TCMs.
ABSTRACT
A method was developed for determining residual narasin in chicken tissues by HPLC with post-column derivatization. The samples were extracted with iso-octane. Further cleanup was performed on LC-si cartridge after centrifugation. Then the eluent was dried by nitrogen and residues were dissolved in methanol, water mixture (90∶ 10 v/v). The samples were analyzed on an Inertsil ODS-3 C18 column with a mixture of methanol-acetic acid-water as the mobile phase and vanillin as the derivatization reagent. The detection wavelength was 520 nm. The samples were quantified with the external standard calibration curve method. The limit of detection and the limit of quantification for narasin in chicken tissues were 6.0 μg/kg and 20 μg/kg, respectively. The average recoveries of narasin in chicken tissues were 76.4 %-93.1 %, the intra-assay relative standard deviations were 2.6 %-8.9% and the inter-assay relative standard deviations were 4.7%-9.7% at spiked levels of 20-1800 μg/kg. There was a good linear correlation (the calibration coefficient is above 0.9993) between the peak areas and concentration of narasin in the range of 70-10000 μg/L.