Determination of Taurine in Biological Samples by High-Performance Liquid Chromatography Using 4-Fluoro-7-Nitrobenzofurazan as a Derivatizing Agent

Objective A highly sensitive and rapid high‐performance liquid chromatography method with pre‐column derivatization with 4‐fluoro‐7‐nitrobenzofurazan was developed for determination of taurine in biological samples,including plasma,brain,and liver.Methods The optimum derivatization reaction temperature was 70℃,and at this temperature the reaction was complete within 3 min.The derivatized taurine was separated using phosphate buffer （0.02 mol/L,pH 6.0）：acetonitrile （84：16,v/v） as the mobile phase at a flow rate of 1.0 mL/min,and a column temperature of 25℃.The taurine derivatives were separated within 20 min （tR：14.5 min） and fluorometrically detected at 530 nm with excitation at 470 nm.Results The intra‐ and the inter‐day coefficients of variation for the method were 5.3% and 7.7%,respectively.The calibration curve was linear from 0.1 μmol/L to 30.0 μmol/L with a correlation coefficient of 0.9995.Conclusion This method can be used to determine the taurine contents in plasma,brain,and liver from normal rats and human plasma.

In situ Synthesis of Rosin Derived Chiral Derivatizing Agents for 31p NMR Assays of Amine and Alcohol Enantiomers

Chiral alcohols（3, 5） were synthesized in optically pure forms from easily available rosin acid in short-steps. A comprehensive protocol for the enantiomeric excess assays of mono- or di-functional-grouped chiral secondary amine or alcohol has been established with them used as chiral auxiliary for chiral phosphorus derivatizing agents（CPDAs） in 3Jp NMR tests. Chemical shift difference（△δp） values ranging from 4.5 to 0.15 between two dias- tereoisomers of the CPDAs and the aryl substrates were obtained. Positive △δR-S was observed for all the tested alco- hol P（III） and P（V） derivatives, while negative △δR-S was observed for all the amines.

Chemical derivatization strategies for enhancing the HPLC analytical performance of natural active triterpenoids

Triterpenoids widely exist in nature,displaying a variety of pharmacological activities.Determining triterpenoids in different matrices,especially in biological samples holds great significance.High-performance liquid chromatography(HPLC)has become the predominant method for triterpenoids analysis due to its exceptional analytical performance.However,due to the structural similarities among botanical samples,achieving effective separation of each triterpenoid proves challenging,necessitating significant improvements in analytical methods.Additionally,triterpenoids are characterized by a lack of ultraviolet(UV)absorption groups and chromophores,along with low ionization efficiency in mass spectrometry.Consequently,routine HPLC analysis suffers from poor sensitivity.Chemical derivatization emerges as an indispensable technique in HPLC analysis to enhance its performance.Considering the structural characteristics of triterpenoids,various derivatization reagents such as acid chlorides,rhodamines,isocyanates,sulfonic esters,and amines have been employed for the derivatization analysis of triterpenoids.This review comprehensively summarized the research progress made in derivatization strategies for HPLC detection of triterpenoids.Moreover,the limitations and challenges encountered in previous studies are discussed,and future research directions are proposed to develop more effective derivatization methods.

气相色谱-甲基化-α-D-甘露糖苷内标法测定变异黄芪中的苦马豆素

建立以甲基化-α-D-甘露糖苷为内标物,用气相色谱测定变异黄芪中苦马豆素的方法。植物样品经甲醇超声提取、氯仿去除杂质后,将碱性正丁醇萃取物用硅烷化试剂进行衍生化,通过AT.SE-54毛细管柱分离,氢火焰离子化检测器检测,测得变异黄芪干草粉中苦马豆素含量为115.7mg/kg,加标回收率为82.6%～94.0%,相对标准偏差为2.8%。该方法能用于疯草样品中苦马豆素的含量检测。

采暖期北京大气气溶胶中有机酸的测定

This paper set up the identification method of BF3/ methanol derivatization,GC-MS for analyzing organic acid in PM2.5 aerosol. The result shows that this method is reliable for monitoring the polar organic acid. Total 34 polar organic acids were identified and quantified, including 23 n-fatty acids and 6 dicarboxylic acids, 5 aromatic acids.The total concentration of n-fatty acids was 62-664 ng·m-3, and the C16 acid was the most abundant acid,followed by C18.

Analysis of Monosaccharide Composition of Pu-erh Tea Polysaccaride by Pre-column Derivatization HPLC

[Objective] This study aimed to establish a pre-column derivatization HPLC method for the identification and analysis of monosaccharide composition of Pu-erh tea polysaccharide. [Method] Pu-erh tea polysaccharide was extracted using the wa- ter extraction method, further isolated and purified by DEAE cellulose-52 columns. The obtained tea polysaccharide and four components TPS1, TPS2, TPS3 and TPS, were first derived by 1-phenyl-3-methyl-5-pyrazolone （PMP）, and then the PMP derivatives of monosaccharide were analyzed by high performance liquid chromatog- raphy （HPLC）. [Result] Pu-erh tea polysaccharide contained eight kinds of monosac- chaddes （mannose, rhamnose, glucuronic acid, galacturonic acid, grucose, galactose, arabinose, fucose）, without xylose; so it was the same with TPS1; each of TPS2, TPS3 and TPS4 contained seven monosaccharides, while no fucose. [Conclusion] This method is simplified and rapid, which can be used to determine the monosac- charide composition of Pu-erh tea polysaccharide and monosaccharide content.

C_(18)固相萃取与GC-MS对生物基质样品中有机锡的测定

A simple and rapid method for determination of monobutyl,dibutyl,tributyl,monophenyl,di-phenyl and triphenyl in bio-matrix has been developed by C18SPE coupled with GC-MS using sodium tetraeth-ylboron as derivatization reagent.Hydrolyzation and extraction of sample were performed with 3 mol/L aceticacid containing0.005%tropolone.The extracts were analyzed by GC-MS under SIMmode and using1 mol/L TPrTas an internal standard.LOD of the method was down to 10 ng/g(dry sample),the recoveries were56%-113%for four samples spiked at50 ng/g with RSD of1.0%-11.9%,and 79%-113%for four sam-ples spiked at200 ng/g with RSD of 0.8%-6.5%,respectively.

Determination of Sulphonylurea Glimepiride in Dog Serum by RP-HPLC with Pre-column Derivatization

Aim A simple, sensitive and rapid RP HPLC method with pre column derivatization has been developed for the determination of sulphonylurea glimepiride in dog serum. Methods The sulphonylurea glimepiride was extracted from the dog serum using dichlromethane followed by derivatization with DNBF for 20 min at 100℃. The solvent was then evaporated at 60℃ under nitrogen, and the residue was taken up in 100 μL of mobile phase consisting of acetonitrile water (75∶30, v/v). The separation was performed on a Hypersil BDS C18 column with a flow rate of 0 8 mL·min -1 , and the ultraviolet detector wavelength was set at 350 nm. Results Extraction recovery ranged from 75.9% to 83.2%, and methodological recovery was between 96.5% and 109.3%. Within day RSD ranged from 1.5% to 6.3%, and inter day RSD was between 2 9% and 14.8%. The method showed good linearity (R=0.9998). Conclusion The method was simple, convenient and sensitive. The reaction of derivatization was reproducible.

A Pre-column Derivatization HPLC Method for the De-termination of Peimine and Peiminine in Bulbus Fritillar-iae

A pre-column derivatization HPLC method for the determination of peimine(P)and peiminine(PE)in Bulbus Fritillariae has been developed. Under the derivatization conditions optimized,the calibration curve is Y1=-3.83×103+1.33 ×105X1,r=0.998 for P and Y2=-7.86 × 102+6.33 × 104X2,r=0995 for PE,where Y is the peak area and X is the weight of the alkaloid; the average recovery is 98.0%(n=5, RSD=2.1%) for P and 101.0%(n=5,RSD=4.1%)for PE,the linear range is from 0.504 μg to 3.126μg for P and from 0.520μgto 3.328μgfor PE,respectively. Results of the determination of the two alkaloids in several samples of different Fritillaria species from various parts ofthe country are presented.The results suggest that P and PE are two major chemical constituents in bulbs of different Fritillaria species,and that the method developed is generally appli-cable to the determination of the hydroxy group on aliphatic fused ring systems without steric hin-drance.

GC-MS法测定头发中多胺的含量

A simple method for the determination of putrescine,spermidine and spermine in hair sample was developed by gas chromatography-mass spectrometry(GC-MS).After alkaline digestion,hair samples were extracted by solid phase extraction(SPE) with diatomaceous earth column,and then derivatized with heptafluorobutyryl chloride(HFB-Cl) in n-hexane.The analytes were determined by a mass spectrometer detector in selected ion monitoring(SIM) mode.A good reproducibility and accuracy were attained.The method was applied to the analysis of the hairs of 14 healthy men and 22 healthy women.Results showed that the most abundant polyamine was spermidine,followed by putrescine and spermine,and the levels of three hair polyamines in men were all found to be higher than in women,respectively.

Determination of Lignin in Marine Sediment Using Alkaline Cupric Oxide Oxidation-Solid Phase Extraction-on-Column Derivatization-Gas Chromatography

Lignin serves as one of the most important molecular fossils for tracing Terrestrial Organic Matters （TOMs） in marine environment. Extraction and derivatization of lignin oxidation products （LOPs） are crucial for accurate quantification of lignin in marine sediment. Here we report a modification of the conventional alkaline cupric oxide （CuO） oxidation method, the modification consisting in a solid phase extraction （SPE） and a novel on-column derivatization being employed for better efficiency and reproducibility. In spiking blanks, recoveries with SPE for the LOPs are between 77.84% and 99.57% with relative standard deviations （RSDs） ranging from 0.57% to 8.04% （n=3）, while those with traditional liquid-liquid extraction （LLE） are from 44.52% to 86.16% With RSDs being from 0.53% to 13.14% （n=3）. Moreover, the reproducibility is greatly improved with SPE, with less solvent consumption and shorter processing time. The average efficiency of on-column derivatization for LOPs is 100.8%±0.68%, which is significantly higher than those of in-vial or in-syringe derivatization, thus resulting in still less consumption of derivatizing reagents.Lignin in the surface sediments sampled from the south of Yangtze River estuary, China, was determined with the established method. Recoveries of 72.66% to 85.99% with standard deviation less than 0.01mg/10g dry weight are obtained except for p-hydroxybenzaldehyde. The lignin content ∑8 （produced from 10g dry sediment） in the research area is between 0.231 and 0.587mg. S/V and C/V ratios （1.028 ± 0.433 and 0.192±0.066, respectively） indicate that the TOMs in this region are originated from a mixture of woody and nonwoody angiosperm plants; the high values or （Ad/Al）v suggest that the TOMs has been highly degraded.

AQC柱前衍生高效液相色谱法测定啤酒中的21种游离氨基酸

采用6-氨基喹啉基-N-羟基琥珀酰亚氨基甲酸酯（AQC）柱前衍生，紫外、荧光双检测器串接，通过梯度洗脱，在AccQ．Tag C18氨基酸专用分析柱上同时分离并定量测定了啤酒中包括天冬酰胺和谷氨酰胺在内的21种游离氨基酸。方法操作简单，准确可靠，具有较高的灵敏度。21种氨基酸在0．01～1．25mmol／L内其浓度与响应值呈线性关系，相关系数（r^2）不小于0．995，大部分氨基酸的加标回收率为92．5％～100．1％。分析了6种啤酒样品，受酵母对氨基酸的同化规律的影响，不同酿造工艺制造的啤酒其氨基酸组成差异明显。

Studies on the Analytical Method for a New Antiarrhythmic Guanfu Base A in Rabbit Plasma

Guan-fu base A(GFA),a new antiarrhythmic alkaloid with a structure of C_(20)-diterpenoid could react rapidly and quantitatively with trifluoroacetic anhydride(TFAA) to produce GFA—TFAA of which the structure was identified by GC—MSD.There was a wide linear range of the GC-ECD method from 10 to 20000ng/ml(r=0.9984).The average recovery of GFA from the spiked plasma was 97.52%.The coefficients of variation of within-day and between-day were less than 7% and 9%,respectively.The method was used in the preclinical experiment of pharmacology of GFA and the results showed that GFA con- centrations in rabbits' plasma within 6 hours after the administration ranged from 0.338± 0.014 to 13.459±5.393μg/ml for dosage 10mg/kg,from 0.133±0.038 to 2.546±0.480 μg/ml for dosage 2mg/kg and from 45.25±10.34 to 535.86±24.36ng/ml for dosage 0.4 mg/kg.

p-Hydrazinobenzenesulfonic Acid Derivatives of Carbohydrates andTheir Capillary Zone Electrophoresis

p-Hydrazinobenzenesulfonic acid is explored as a novel ultraviolet labeling reagent for capillary electrophoresis (CE) of mono- and disaccharides. The labeling reaction takes less than 10 minutes and introduces both of absorption and charge groups into the sugars.

Microanalysis and preliminary pharmacokinetic studies of a sulfated polysaccharide from Laminariajaponica

A rapid, sensitive and reproducible high performance liquid chromatography （HPLC） method with post-column fluorescence derivatization has been developed to determine the amount of low-molecular- weight sulfated polysaccharide （GFS） in vivo. The metabolism of GFS has been shown to fit a two component model following its administration by intravenous injection, and its pharmacokinetic parameters were determined to be as follows： half-time of distribution phase （t1/2α）=11.2±2.93 min, half-time of elimination phase （tl/2α）=98.20±25.78 min, maximum concentration （Cmax）=110.53 gg/mL and peak time （Tmax）=5 min. The pharmacokinetic behavior of GFS was also investigated following intragastric administration. However, the concentration of GFS found in serum was too low for detection, and GFS could only be detected for up to 2 h after intragastric administration （200 mg/kg body weight）. Thus, the bioavailability of GFS was low following intragastric administration because of the metabolism of GFS. In conclusion, HPLC with post-column derivatization could be used for quantitative microanalysis and pharmacokinetic studies to determine the presence of polysaccharides in the serum following intravenous injection.

Precolumn derivatization LC-MS/MS method for the determination and pharmacokinetic study of glucosamine in human plasma and urine

A selective precolumn derivatization liquid chromatography–tandem mass spectrometric (LC–MS/MS) method for the determination of glucosamine in human plasma and urine has been developed and validated. Glucosamine was derivatized by o-phthalaldehyde/3-mercaptopropionic acid. Chromatographic separation was performed on a Phenomenex ODS column (150 mm 4.6 mm, 5 mm) using linear gradient elution by a mobile phase consisting of methanol (A), and an aqueous solution containing 0.2% ammonium acetate and 0.1% formic acid (B) at a flow rate of 1 mL/min. Tolterodine tartrate was used as the internal standard (IS). With protein precipitation by acetonitrile and then the simple one-step derivatization, a sensitive bio-assay was achieved with the lower limit of quantitation (LLOQ) as low as 12 ng/mL for plasma. The standard addition calibration curves suitable for clinical sample analysis showed good linearity over the range of 0.012–8.27 mg/mL in plasma and 1.80–84.1 mg/mL in urine. The fully validated method has been successfully applied to a pharmacokinetic study of compound glucosamine sulfate dispersible tablets in health Chinese volunteers receiving single oral doses at 500, 1000 and 1500 mg of glucosamine sulfate, as well as multiple oral doses of 500 mg t.i.d. for 7 consecutive days.

Enantioselective assay of S(+)- and R(-)-propafenone in human urine by using RP-HPLC with pre-column chiral derivatization

The enantioselective assay for S(+)- and R(-)-propafenone (PPF) in human urine that developed in this work involves extraction of propafenone from human urine and using S(+)-propafenone as internal standard, chiral derivatization with 2,3,4,6-tetra-O-b-D-glucopranosyl isothiocyanate, and quantitation by an RP-HPLC system with UV detection (l=220 nm). A baseline separation of propafenone enantiomers was achieved on a 5-mm reverse phase ODS column, with a mixture of methanol:water:glacial acetic acid (25:12:0.02,v/v) as mobile phase. There was good linear relationship from 24.9 ng/ml to 1875.0 ng/ml for both of enantiomers. The regression equations of the standard curves based on CS-PPF (or CR-PPF ) versus ratio of AS-PPF/AS (or AR-PPF/AS ) were y=0.0032x-0.081, (r=0.999) for S-PPF and y=0.0033x+0.0039, (r=0.998) for R-PPF, respectively. The method抯 limit of detection was 12.5 ng/ml for both enantiomers, and the method抯 limit of quantitation was 28.20.52 ng/ml for S-PPF, 30.40.53 ng/ml for R-PPF (RSD<8%, n=5). The analytical method yielded average recovery of 98.9% and 100.4% for S-PPF and R-PPF, respectively. The relative standard deviation was no more than 6.11% and 6.22% for S-PPF and R-PPF, respectively. The method enabled study of metabolism of S(+)- and R(-)-propafenone in human urine. The results from 7 volunteers administered 150 mg racemic propafenone indicated that propafenone enantiomers undergo stereoselective metabolism and that in the human body, S(+)-propafenone is metabolized more extensively than R(-)- propafenone.

Determination of sodium hyaluronate in pharmaceutical formulations by HPLC–UV

A liquid chromatography （HPLC） method with UV detection was developed for determination of sodium hyaluronate in pharmaceutical formulation. Sodium hyaluronate is a polymer of disaccharides, composed of D-glucuronic acid and D-N-acetylglucosamine, linked via alternating 13-1, 4 and D-l, 3 glycosidic bonds. Being a polymer compound it lacks a UV absorbing chromophore. In the absence of a UV absorbing chromophore and highly polar nature of compound, the analysis becomes a major challenge. To overcome these problems a novel method for the determination of sodium hyaluronate was developed and validated based on size exclusion liquid chromatography （SEC） with UV detection. An isocratic mobile phase consisting of buffer 0.05 M potassium dihydrogen phosphate, pH adjusted to 7.0 using potassium hydroxide （10%） was used. Chromatography was carried out at 25 ~C on a BioSep SEC $2000, 300 mm ~ 7.8 mm column. The detection was carded out using variable wavelength UV-vis detector set at 205 nm. The compounds were eluted isocratically at a steady flow rate of 1.0 mL/min. Sodium hyaluronate retention time was about 4.9 min with an asymmetry factor of 1.93. A calibration curve was obtained from 1 to 38 g/mL （r〉0.9998）. Within-day % RSD was 1.0 and between-day % RSD was 1.10. Specificity/selectivity experiments revealed the absence of interference from excipients, recovery from spiked samples for sodium hyaluronate was 99-102. The developed method was applied to the determination of sodium hyaluronate in pharmaceutical drug substance and product.