Determination of Benzo[a]pyrene in Edible Oil by High Performance Liquid Chromatography-Fluorescence Detector (HPLC-FL)

In this study, an optimized high performance liquid chromatography-fluorescence detector (HPLC-FL) method for the determination of benzo[a]pyrene in edible oil was established. HPLC was performed with Thermo Fisher Scientific C18 column (250 mm×4.6 mm, 5 μm) as the chromatographic column and acetonitrile and water as the mobile phase, and the excitation wavelength and emission wavelength of fluorescence detector were 286 and 430 nm, respectively. The response was high, and the linear range was 0.5-10.0 ng/ml. The lowest limit of detection was 0.11 ng/ml, and the average recovery was 92.5%. This method is suitable for quantitative analysis of benzo[a]pyrene content in edible oil.

A High-Performance Liquid Chromatography Method for the Simultaneous Determination of Five Index Components in Danhong Injection

The purpose of this study was to establish a high-performance liquid chromatography (HPLC) method for the simultaneous determination of sodium danshensu, protocatechuic aldehyde, rosmarinic acid, salvianolic acid B, and 4-coumaric acid in Danhong injection. The chromatographic method employed was as follows: the column was a Welch Ultimate XB-C18 column (250 mm × 4.6 mm, 10 μm), the mobile phase was a gradient elution of 0.4% formic acid aqueous solution (A) and acetonitrile (B), the detection wavelengths were 280 nm for sodium danshensu, protocatechuic aldehyde, and salvianolic acid B and 326 nm for 4-coumaric acid and rosmarinic acid, the sample volume was 10 μL, the flow rate was 1.0 mL/min, and the column temperature was 35°C. This method can realize the separation and determination of sodium danshensu, protocatechuic aldehyde, rosmarinic acid, salvianolic acid B, and 4-coumaric acid within 50 minutes. The linear relationships of the five peak areas and their concentrations are good (R2> 0.9997). The precision RSD values are all less than 1.0%. The reproducibility RSD values are all less than 1.3%. The stability RSD values are all less than 2.2%. The recovery values ranged from 92.4% to 99.4%. This method is simple, accurate, and reproducible. It can be used for the determination of sodium danshensu, protocatechuic aldehyde, rosmarinic acid, salvianolic acid B, and 4-coumaric acid in Danhong injection.

Simultaneous Determination of 14 β-Receptor Agonists Residues in Mutton by High Performance Liquid Chromatography-Tandem Mass Spectrometry (HPLC-MS/MS)

[Objectives]A high performance liquid chromatography-tandem mass spectrometry(HPLC-MS/MS)method was established for the determination of 14β-receptor agonist residues in mutton.[Methods]Samples were hydrolyzed byβ-glucuronidase and extracted with 5%acetic acid-acetonitrile(1:99,V/V)solution.An Eclipse plus C 18 column was used for separation,and the MRM mode was used for qualitative analysis,and the external standard method was used for quantitative analysis of matrix standard solutions.[Results]Under the optimal conditions,the retention time of the 14 kinds ofβ-receptor agonists ranged from 1.0 to 9.5 min.When the mass concentration was in the range of 0.05-0.50μg/ml,the linear relationship ofβ-receptor agonists was good,with correlation coefficients(r)≥0.9992.The detection limits of the method were in the range of 0.04-0.87μg/kg,and the quantitative limits were in the range of 0.35-1.86μg/kg.The average recovery values were in the range of 82.8%-108.9%,with RSDs(n=6)in the range of 1.9%-6.7%.[Conclusions]The method is simple,sensitive,reproducible,accurate,and can be used for simultaneous determination of the 14 kinds ofβ-receptor agonist residues in mutton.

Novel method for the determination of five carbamate pesticides in water samples by dispersive liquid-liquid microextraction combined with high performance liquid chromatography

A novel method for the determination of five carbamate pesticides （metolcarb, carbofuran, carbaryl, isoprocard and diethofencard） in water samples was developed by dispersive liquid-liquid microextraction （DLLME） coupled with high performance liquid chromatography-diode array detector （HPLC-DAD）. Some experimental parameters that influence the extraction efficiency were studied and optimized to obtain the best extraction results. Under the optimum conditions for the method, the calibration curve was linear in the concentration range from 5 to 1000 ng mL^-1 for all the five carbamate pesticides, with the correlation coefficients （r^2） varying from 0.9984 to 0.9994. Good enrichment factors were achieved ranging from 80 to 177- fold, depending on the compound. The limits of detection （LODs） （S/N = 3） were ranged from 0.1 to 0.5 ng mL^-1. The method has been successfully applied to the analysis of the pesticide residues in environmental water samples.

Determination of Residual Acrylamide in Medical Polyacrylamide Hydrogel by High Performance Liquid Chromatography tandem Mass Spectroscopy

Objective To determine residual acrylamide in medical polyacrylamide hydrogel by high performance liquid chromatography tandem mass spectroscopy （HPLC-MS）. Methods After 13C3 labeled acrylamide was added, the sample was extracted with water and then cleaned up with ExtrelutTM 20. The polyacrylamide hydrogel sample and 20 clinical cases were analyzed by HPLC-MS/MS and isotope dilution quantifying technique in selected reaction monitoring （SRM） mode. Results Acrylamide was separated from polyacrylamide hydrogel. The concentration of acrylamide in polyacrylamide hydrogel ranged from 3.9×10^-9 to 3.1×10^- 8g/L in the 20 clinical cases. The peak area was favorable linear and the range was up to 3 000 μg/L. The recovery rate was 103.1% with a relative standard deviation （RSD） of 6.20%, when the mark level was 50 lag/L. Conelusion HPLC-MS is a rapid, accurate, and sensitive method for the determination of residual acrylamide in medical polyacrylamide hydrogel.

Determination of the Flavonoids from Ginkgo Biloba Extract by High Performance Liquid Chromatography

HPLC method for analysis of the flavonoids from ginkgo biloba extract (GBE) was studied. By suitable selection of columns. symmetrical chromatographic peaks were obtained without using acidic modifier in the mobile phase, which can eliminate the time for cleaning the chromatographic system and simplify the analystic method for GBE Experimental conditions: column: Hypersil BDS C-18, 5mumx4x250 mm: column temperature: 35degreesC; mobile phase: 46% methanol-54% water; flow rate: 0.7 mL/min; detection wavelength: 360nm.

Bio-analytical method development and validation of Rasagiline by high performance liquid chromatography tandem mass spectrometry detection and its application to pharmacokinetic study

The most suitable bio-analytical method based on liquid liquid extraction has been developed and validated for quantification of Rasagiline in human plasma. Rasagiline-13C3 mesylate was used as an internal standard for Rasagiline. Zorbax Eclipse Plus C18 （2.1 mm × 50 mm, 3.5 um） column provided chromatographic separation of analyte followed by detection with mass spectrometry. The method involved simple isocratic chromatographic condition and mass spectrometric detection in the positive ionization mode using an API-4000 system. The lotal run time was 3.0 min. The proposed method has been validated with the linear range of 5 12000 pg/mL for Rasagiline. The intra-run and inter-run precision values were within 1.3% 2.9% and 1.6% 2.2% respectively for Rasagiline. The overall recovery for Rasagiline and Rasagiline-13C3 mesylate analog was 96.9% and 96.7% respectively. This validated method was successfully applied to the bioequivalence and pharmacokinetic study of human volunteers under fasting condition.

Fingerprint analysis of placenta polypeptide injection by high performance liquid chromatography

Objective: To develop the representative fingerprint for the quality control of placenta polypeptide injection. Methods: The chromatographic separation was performed using a Phenomenex Gemini C18 column (250 mm 4.6 mm, 5 mm) maintained at 30 1C. 0.1% aqueous trifiuoroacetic acid (Solvent A) and acetonitrile contained 0.1% TFA (Solvent B) were used as mobile phase with a gradient elution. Detection wavelength was 280 nm with the sample injection volume of 50 mL; the fiow rate was 1.0 mL/min. The fingerprints of different samples were investigated by similarity analysis. Results: Nine peaks were identified as the characteristic common peaks. The similarities of the fingerprints of the 10 batches of samples were above 0.992. Conclusion: This method showed high precision and good repeatability, and provided the basis for the improvement of the quality control of placenta polypeptide injection.

Determination of 17<i>α</i>-Methyltestosterone in Freshwater Samples of Tilapia Farming by High Performance Liquid Chromatography

17α-methyltestosterone is used to induce the sex reversal of Tilapia sp. to obtain cultures mono-sex to an economically viable. This practice may lead to environmental contamination and problems in human health. Therefore methods need to be developed to detect residues of 17α-methyltestosterone in aqueous matrices. A simple high-performance liquid chromatographic method using ultraviolet detection (245 nm) and testosterone as internal standard has been developed for the monitoring 17α-methyltestosterone in freshwater samples of tilapia aquaculture. The method described involves limited sample preparation as it includes a filtration followed by a single solid-phase extraction step using C18 cartridge. Validation data indicated that the HPLC-UV method for 17α-methyltestosterone determination in the concentration range of 50 - 2000 μg/L provided good linearity, sensitivity, accuracy and precision. Method performance was efficiently applied to monitoring the freshwater samples of fish ponds and the surrounding aquatic channels.

Analysis of ganciclovir and its related substances using high performance liquid chromatography and liquid chromatography-mass spectrometry methods

Objective High performance liquid chromatography(HPLC)and liquid chromatography-mass spectrometry(LC/MS)methods were developed for the determination of ganciclovir and its related substances.Methods A Hypersil ODS2 column(4.6 mm×250 mm,5 μm)was used with a mobile phase of 0.02 M potassium dihydrogen phosphate buffer(pH 6.0)-methanol(92∶8)at a flow rate of 1.0 mL/min,and UV detector set at 254 nm was used for monitoring the eluents.Results The method was simple,rapid,selective and capable of separating all related substances at trace level with a detection limit of 0.04 μg/mL.It has been validated with respect to accuracy,precision,linearity,and limits of detection and quantification.The linearity range was 10.2-153.0 μg/mL with r=0.9998.The percentage recoveries ranged from 96.7% to 101.6%,and RSD was 1.24%-1.96%(n=5).Conclusion The method was found to be suitable not only for monitoring the reactions during the process development but also for quality control of ganciclovir.For identification of related substances,LC/MS was used.The mainly related substances of ganciclovir active pharmaceutical ingredients(API)were determined as guanine,(1,3-dioxolan-4-yl)methyl acetate,and diacetyl guanine.

Determination of Trace Amount of Polycyclic Aromatic Hydrocarbons in Urban Sewage by Solid-phase Extraction Coupled with High Performance Liquid Chromatograph

[Method] This study aimed to determine trace amount of polycyclic aromatic hydrocarbons(PAHs) in urban sewage by using solid-phase extraction(SPE) coupled with high performance liquid chromatograph(HPLC).[Method] From the aspects of solid-phase extraction column,elution solvent,elution volume,elution speed and so forth,the test conditions of SPE-HPLC method were optimized,and trace amount of PAHs in urban sewage was determined.[Result] The optimized solid-phase extraction conditions were SUPELCLEAN LC-18 solid-phase extraction column,methylene dichloride as elution solvent,15 ml elution volume,2 ml/min elution speed,5 ml/min loading speed,1 000 ml water with 200 ml methanol loading volume.Under the optimized extraction conditions,the recovery was high,namely 76.3%-105.2%;relative standard deviation was 3.8%-6.0%,showing good precision;detection limit was low,only 0.000 8-0.048 0 μg/L.[Conclusion] This method is user-friendly,with high sensitivity and good precision,and suitable for continuous determination of a large volume of water samples.

Isolation and Purification of Unstable Iridoid Glucosides from Traditional Chinese Medicine by Preparative High Performance Liquid Chromatography Coupled with Solid-phase Extraction

An efficient preparative method was successfully developed for isolation and purification of unstable components from medicinal plant extracts, using a combined method of preparative high performance liquid chro-matography(HPLC) and solid-phase extraction(SPE). The aim of this study was to obtain an effective method with high preparative efficiency and importantly to avoid the transformation of unstable compounds. The preparative HPLC system was based on an LC/MS controlled four-channel autopurification system. The SPE method was performed with a C18 packing material to trap the target compounds and to remove the acidic additive derived from the mobile phase. Using this method, the unstable iridoid glucosides(IGs) as model compounds were successfully isolated and purified from the extract of Hedyotis diffusa Willd. Six IGs(including one new minor IG) and one nucleotide compound were simultaneously obtained, each with a purity of 91% as determined by HPLC. The structures of the isolated compounds were identified by UPLC/Q-TOF MS, UV, 1D and/or 2D NMR. It was demonstrated that the combination of preparative HPLC with SPE is a versatile tool for preparative purification of unstable compounds from complex natural products.

On-line enrichment and determination of polycyclic aromatic hydrocarbons in atmospheric particulates using high performance liquid chromatography with fluorescence as detector

Seven polycyclic aromatic hydrocarbons （PAHs） in atmospheric particulates were determinated by high performance liquid chromatography （HPLC） with fluorescence detector using direction injection and an on-line enrichment trap column. The method simplified the sample pretreatment, saved time and increased the efficiency. With the on-line trap column, PAHs were separated availably even underground injecting 1.0 ml sample with relatively high column efficiency. The recoveries of the seven PAHs were from 85% to 120% for spiked atmospheric particulate sample. The limit of detection was 15.3-39.6 ng/L （S/N=3.3）. There were good linear correlations between the peak areas and concentrations of the seven kinds of PAHs in the range of 1-50 ng/ml with the correlation coefficients over 0.9970. Furthermore, it also indicated that the method is available to determine PAHs in atmospheric particulates well.

Rapid Determination of Dopamine and Its Metabolites During in vivo Cerebral Microdialysis by Routine High Performance Liquid Chromatography With Electrochemical Detection

To determine dopamine and its metabolites during in vivo cerebral microdialysis by routine high performance liquid chromatography with electrochemical detection. Methods Microdialysis probes were placed into the right striatum of Wistar rat brains and perfused with Ringer＇s solution at a rate of 1.5 pL/min. A reverse phase HPLC with electrochemistry was used to assay DA, DOPAC, and HVA after cerebral microdialysates were collected every 20 minutes from awake and freely moving rats. In order to identify the reliability of this method, its selectivity, linear range, precision and accuracy were tested and the contents of DA, DOPAC, and HVA in rat microdialysates were determined. Results The standard curve was in good linear at the concentration ranging from 74 nmol/L to 1.5 pmol/L for DOPAC （r^2= 0.9996）, from 66 nmol/L to 1.3 gmol/L for DA （r^2=l.0000） and from 69 nmol/L to 1.4 pmol/L for HVA （r^2=0.9992）. The recovery of DOPAC （0.30, 0.77, 1.49 gmol/L）, DA （0,26, 0.69, 1.32 gmol/L）, and HVA （0.27, 0.71, 1.37 gmol/L） was 82.00±1.70%, 104.00±4.00%, 98.70±3.10%; 92.30± 1.50%, 105.30±2.30%, 108.00±2.00%; 80.00±7.80%, 107.69±8.00%, and 108.66±3.10%, respectively at each concentration. Their intra-day RSD was 3.3%, 3.4%, and 2.5%, and inter-day RSD was 4.2%, 2.3%, and 5.6%, respectively. The mean extracellular concentrations of DOPAC, DA, and HVA in rat brain microdialysates were 10.7, 2.4, and 9.2 gmol/L （n=6）, respectively. Conclusion The findings of our study suggested that the simple, accurate and stable method can be applied to basic researches of diseases related to monoamines neurotransmitters by cerebral microdialysis in rats.

High Performance Liquid Chromatography Analysis of Sugars and Acid Components in ’Xintai Tianhong’ Hawthorn Fruit

[Objectives]This study was conducted to provide basic information for the utilization,quality control and deep processing of‘Xintai Tianhong’hawthorn fruit resources.[Methods]The contents of sugar and acid components in‘Xintai Tianhong’hawthorn fruit were determined by high performance liquid chromatography(HPLC).[Results]‘Xintai Tianhong’hawthorn fruit contained such four kinds of sugar components as fructose,sorbitol,glucose and sucrose,and such six kinds of organic acid components as oxalic acid,tartaric acid,malic acid,acetic acid,citric acid and succinic acid.The fruit had the highest sucrose content,accounting for 70.53%of the total sugar content,followed by fructose,glucose and sorbitol.For the organic acid components,the content of succinic acid was the highest,accounting for 47.32%of the total acid content,followed by citric acid,malic acid,oxalic acid and tartaric acid,and acetic acid had the lowest content.[Conclusions]‘Xintai Tianhong’hawthorn should be a succinic acid-type hawthorn variety,which can be used as a parent in genetic research and breeding practice.

Chemical Components of Achyranthes bidentata Leaves by Ultra High Performance Liquid Chromatography-Mass Spectrometry

[Objectives] To study the chemical components and relative content of Achyranthes bidentata leaves and provide a scientific basis for further development and utilization of A. bidentata leaves.[Methods] The chemical components of A. bidentata leaves were rapidly analyzed using the ultra high performance liquid chromatography-time of flight-high resolution mass spectrometry (UHPLC-TOF-MS).[Results] Thirty eight chemical compounds were identified in samples of A. bidentata leaves collected from Wen County of Henan Province, in which seven chemical compounds had the relative content higher than 5%, linoleic acid reached 25.7% and inokosterone A reached 13.8%.[Conclusions] A. bidentata leaves contain many kinds of chemical compounds. This study is expected to provide a certain basis for further extraction of linoleic acid and inokosterone A.

Determination of Melamine in Animal Blood Products by High Performance Liquid Chromatography

[Objective] To investigate the optimal determination conditions of melamine in animal blood products by high performance liquid chromatography （HPLC）. [ Method] The blood samples were extracted with ultrasonic in 1% trichloroacetic acid （TDA） and acetonitrile. After purifying by solide phase extraction （SPE）, the samples were analyzed by H PLC. r Result I The optimal conditions of HPLC were as follows： the chromatographic column was Zorbax SB-CS; the mobile phase was ion-pairs buffer-acetonitrile （95/5, V/V） ; the flow rate was 1.0 ml/min; the column temperature was 25 ℃ and the UV detection wavelength was 235 nm. The determined melamine concentration range was 0.001 -0.050 mg/ml; the linear correlation coefficient was 0.999 4; the concentration limit of melamine was 0.1 mg/kg; the average recovery rate of the melamine were 97.60% - 100.65%, and the relative standard deviation （RSD） was 1.23% -3.04%.[ Conclusion] The HPLC is simple, accurate and repeatable for determination of the melamine in animal blood products.

Metabolomic Studies Using High Performance Liquid Chromatography and Tandem Mass Spectrometry to Discover Quality Markers for Oriental Beauty (Dongfang Meiren) Tea

In this study, a high-performance liquid chromatograph and an electrospray ionization (ESI) triple quadrupole mass spectrometry (TQ MS) detector were used to scan Oriental Beauty tea of different grades and prices. Principle component analysis (PCA) of the profiling data was performed for pattern recognition, clearly showing that the proposed MS profiling method was able to classify Oriental Beauty tea into different grades. The component mass ions primarily responsible for the separation were selected with high loading strength in the PCA for subsequent identification with tandem mass (MS/MS). Caffeine, citrate and salicylate were verified, whereas certain other compounds remained ambiguous. Regression analysis considering caffeine, citrate and salicylate showed a linear relationship between the prices of the Oriental Beauty tea with an adjusted R2 of 0.84. If all the selected marker ions (in addition to caffeine, citrate and salicylate) could have been identified and incorporated into regression analysis, a stronger relationship could have been confirmed. These results suggest that metabolomics can facilitate the determination of real markers in the quality control of Oriental Beauty tea, and may lead to the further application of metabolomics in other food quality controls.

Research Advances in Detection Techniques of High Performance Liquid Chromatography-Refractive Index Detector

As a highly sensitive and stable detector,refractive index detector is usually used for quantitative detection of substances such as polymer,sugar and organic acid. The research reviewed the application of HPLC-RID in the fields of quantitative determination of medicine and food,in order to lay a foundation for wider use of RID.

Determination of AF and AFG in Red Ginseng by High Performance Liquid Chromatography with Evaporative Light Scattering Detector (HPLC-ELSD)

[Objective]The paper was to establish a method for determining AF and AFG in red ginseng.[Method]A new simple,rapid and sensitive method for simultaneous determination of two amadori compounds,arginyl-fructose(AF)and arginyl-fructosyl-glucose(AFG),in extracts of three kinds of ginseng preparations was developed and validated using high performance liquid chromatography with evaporative light scattering detector(HPLC-ELSD).Two target analytes were efficiently separated by Prevail CTM18 column(4.6 mm×250 mm,5μm)at the flow rate of 0.8 mL/min within 15 min of single chromatographic run.[Result]Under optimized conditions,the detection limits were 0.015 and 0.02 mg/mL for AF and AFG,respectively.Calibration curves of peak area for two analytes were linear over three orders of magnitude with the correlation coefficients greater than 0.999.The average recoveries,precision,reproducibility and stability for two analytes(AF and AFG)were 99.5% and 100.9%,0.43% and 0.47%,0.46% and 0.43%,0.41% and 0.49%,respectively.[Conclusion]This method was successfully applied for quantifying AF and AFG in red ginseng and the method was efficient,sensitive and accurate.