scholarly journals Determining the Levels of Four Phenylethanoid Glycosides and Five Triterpene Acids in Liuwei Dihuang Capsule Using Solid Phase Extraction with HPLC-UV

2019 ◽  
Vol 2019 ◽  
pp. 1-9
Author(s):  
Yong Zhang ◽  
Xian-Liang Zou ◽  
Yong-Li Wang ◽  
Lu Gao ◽  
Gui-Xin Chou
Keyword(s):  
Solid Phase Extraction ◽  
High Performance ◽  
Solid Phase ◽  
Phase Extraction ◽  
Phenylethanoid Glycosides ◽  
Triterpene Acids ◽  
Ultraviolet Detector ◽  
Relative Standard ◽  
Removal Of Impurities

In this study, we used quantitative high-performance liquid chromatography equipped with an ultraviolet detector (HPLC-UV) and solid phase extraction (SPE) to determine the levels of four phenylethanoid glycosides and five triterpene acids in Liuwei Dihuang capsules (LDCs). LDCs were methanol-extracted and purified using a 500 mg/6 mL silica-based C18 SPE cartridge. Two elutions were analyzed on a ChromCore C18 column under two HPLC conditions. To improve the pretreatment clean-up, an array of silica- and polymer-based SPE cartridges were compared. Both wash and elution steps were also optimized to achieve the highest removal of impurities. Under optimal chromatographic conditions, good linearity was achieved for all compounds (correlation coefficient of r ≥ 0.999), with a quantification limit ranging from 0.0076 to 0.418 μg/mL. The method had satisfactory efficiency and reproducibility with recovery rates ranging from 91.6 to 99.3% with a relative standard deviation below 1.5%. Taken together, this demonstrated SPE as a suitable extension of HPLC-UV for the determination of phenylethanoid glycosides and triterpene acids in complex LDCs.

scholarly journals Simultaneous Determination of Nitroimidazole Residues in Honey Samples by High-Performance Liquid Chromatography with Ultraviolet Detection

2007 ◽  
Vol 90 (3) ◽  
pp. 872-878 ◽  
Author(s):  
Jinhui Zhou ◽  
Jianzhong Shen ◽  
Xiaofeng Xue ◽  
Jing Zhao ◽  
Yi Li ◽  
...  
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Solid Phase Extraction ◽  
Simultaneous Determination ◽  
High Performance ◽  
Solid Phase ◽  
Phase Extraction ◽  
Ultraviolet Detection ◽  
Ultraviolet Detector

Abstract A rapid and sensitive high-performance liquid chromatography (LC) method was developed for the simultaneous determination of metronidazole (MNZ), dimetridazole (DMZ), ronidazole (RNZ), tinidazole (TNZ), and 2-hydroxymethyl-1-methyl-5-nitroimidazole (HMMNI) in honey. After extraction with ethyl acetate and evaporation, the residue containing the nitroimidazoles was dissolved in ethyl acetatehexane and subjected to solid-phase extraction cleanup by amine extraction columns. The effluent was evaporated to dryness, and residues were dissolved and determined by LC with an ultraviolet detector set at 315 nm. The limits of detection were 1.02.0 ng/g for MNZ, DMZ, RNZ, TNZ, and HMMNI in honey. Average recoveries ranged from 71.5101.4% in honey fortified at 10, 20, 50, and 100 ng/g. The method was validated for the analysis of real honey samples.

scholarly journals Automated Online Solid-Phase Extraction Coupled with Sequential Injection-HPLC-EC System for the Determination of Sulfonamides in Shrimp

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Pimkwan Chantarateepra ◽  
Weena Siangproh ◽  
Shoji Motomizu ◽  
Orawon Chailapakul
Keyword(s):  
Solid Phase Extraction ◽  
High Performance ◽  
Solid Phase ◽  
Sequential Injection Analysis ◽  
Phase Extraction ◽  
Sequential Injection ◽  
Elution Time ◽  
Online Solid Phase Extraction ◽  
Relative Standard

The use of fully automated online solid-phase extraction (SPE) coupled with sequential injection analysis, high-performance liquid chromatography (HPLC), and electrochemical detection (EC) for the separation and determination of sulfonamides has been developed. A homemade microcolumn SPE system coupled with sequential injection analysis (SIA) was used to automate the sample cleanup and extraction of sulfonamides. The optimal flow rate of sample loading and elution was found to be 10 μL/s, and optimal elution time of zone was 20–24 s. Under the optimal conditions, a linear relationship between peak area and sulfonamide concentrations was obtained in the range of 0.01–8.0 μg mL−1. Detection limits for seven sulfonamides were between 1.2 ng mL−1and 11.2 ng mL−1. The proposed method has been applied for the determination of sulfonamides in shrimp. Recoveries in the range of 84–107% and relative standard deviations (RSDs) below 6.5% for intraday and 13% for inter-day were received for three concentration levels of spiking. The results showed that the present method was simple, rapid, accurate and highly sensitive for the determination of sulfonamides.

scholarly journals A novel sorbent for solid-phase extraction coupling to high performance liquid chromatography for the determination of olaquindox in fish feed 

2014 ◽  
Vol 32 (No. 5) ◽  
pp. 449-455 ◽  
Author(s):  
D. Zhao ◽  
Q.Y. Shi ◽  
X. He ◽  
J. Zhang
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Solid Phase Extraction ◽  
High Performance ◽  
Solid Phase ◽  
Fish Feed ◽  
Phase Extraction ◽  
Molecularly Imprinted ◽  
Relative Standard

A new and hydrophilic molecularly imprinted polymer (MIP) selective for olaquindox was prepared by bulk polymerisation using methacrylic acid as the functional monomer and ethylene glycol dimethacrylate as the crosslinker. The synthesised polymer was characterised by Fourier-transform infrared and static adsorption experiments. Results showed that the MIP had good recognition and selective ability for olaquindox. A novel method based on molecularly imprinted solid-phase extraction coupled with high-performance liquid chromatography was developed for the separation and determination of trace olaquindox in feed samples. Under selected experimental conditions, the detection limit (signal-to-noise ratio = 3) was 42.2 ng/g, and the relative standard deviation (RSD) for five replicate extractions of 50 µg/l olaquindox was 4.9%. The method provided high recoveries ranging from 89.8% to 93.1% at three spiked levels with < 5% RSDs. This method was successfully applied for the analysis of olaquindox in feed.  

scholarly journals Determination of polyphenols in beer by an effective method based on solid-phase extraction and high performance liquid chromatography with diode-array detection

2008 ◽  
Vol 25 (No. 4) ◽  
pp. 182-188 ◽  
Author(s):  
M. Dvořáková ◽  
P. Hulín ◽  
M. Karabín ◽  
P. Dostálek
Keyword(s):  
Solid Phase Extraction ◽  
High Performance ◽  
Solid Phase ◽  
Diode Array ◽  
Diode Array Detection ◽  
Phase Extraction ◽  
Spectrophotometric Detection ◽  
Relative Standard ◽  
Array Detection

The determination of polyphenols by spectrophotometric detection is complicated due to their low concentrations in beer. The beer samples have to be pre-concentrated before using the spectrophotometric detection for their quantification. An analytical method based on solid-phase extraction (SPE) and followed by high performance liquid chromatographic separation with diode-array detection is used for the determination of free gallic, protocatechuic, caffeic, p-coumaric, ferulic and salicylic acids, of (+)-catechin, (–)-epicatechin, and quercetin. These phenolic compounds participate in colloidal and sensory stability of beer. Six different SPE cartridges were tested and three different types of elution with the most appropriate solvents (acetonitrile, acetone and methanol) were used. The performance of the HPLC method was assessed by the evaluation of parameters such as absolute recovery, relative standard deviation (RSD – lower than 10%), the limit of quantification (LOQ), and the limit of detection (LOD). The polyphenol content in various types of Czech beer is presented.

The Investigation of Electrospun Polymer Nanofibers as a Solid-Phase Extraction Sorbent for the Determination of Benzimidazoles in Pork

2013 ◽  
Vol 662 ◽  
pp. 239-242
Author(s):  
Jing Sun ◽  
Yu Wang ◽  
Xiao Ling Zhou ◽  
Xue Jun Kang
Keyword(s):  
Solid Phase Extraction ◽  
High Performance ◽  
Solid Phase ◽  
Extraction Procedure ◽  
Phase Extraction ◽  
Target Compound ◽  
Ultraviolet Detector ◽  
Polymer Nanofiber ◽  
Optimized Conditions

A novel micro-extraction procedure was developed through the use of an electrospun polymer nanofiber as a solid-phase extraction (SPE) sorbent to directly extract benzimidazoles in pork. The target compound was then monitored by a high performance liquid chromatography with ultraviolet detector (HPLC-UV) system. The eluted solvent was investigated meanwhile. Under the optimized conditions, a linear response for benzimidazoles over the range of 20-1000 ng mL−1 was achieved with the γ2 >0.99. The recoveries were in the range of 95.4%~101.2%. RSDs of intra-day and inter-day assays were 3.5%~6.3% and 5.7%~9.9%. The method is simple, sensitive, accurate and repeatable, which can be used for the determination of benzimidazoles in pork.

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