scholarly journals Rapid Determination of Lysine in Biological Samples by Isocratic Liquid Chromatography

1999 ◽  
Vol 82 (4) ◽  
pp. 809-813 ◽  
Author(s):  
Mamun M Or-Rashid ◽  
Ryoji Onodera ◽  
Shaila Wadud ◽  
Mohamed-Emad A Nasser ◽  
Mohammad R Amin
Keyword(s):  
Liquid Chromatography ◽  
Biological Samples ◽  
Limit Of Detection ◽  
Rapid Determination ◽  
Rumen Fluid ◽  
Uv Detector ◽  
Rumen Microorganisms ◽  
Microbial Nitrogen ◽  
Limit Of Quantitation

Abstract A simple, rapid, and sensitive method was developed for detection and quantitation of lysine (Lys) in various biological samples by isocratic liquid chromatography (LC). Samples containing Lys and other amino acids were derivatized with 9-fluorenylmethyl chloroformate (FMOC-CI). The mobile phase used for isocratic elution was 50 mmol/L sodium acetate buffer (pH 4.20)-acetonitrile (43 + 57, v/v). Lys was detected with a UV detector at 265 nm. The derivatized Lys eluted from a LiChrospher 100 RP-18 (150× 4.0 mm id) column at a retention time of 5.6 min. The limit of detection was 0.73 μmol/L (signal-to-noise [S/N] ratio, 3:1), and the limit of quantitation was 2.37 μmol/L (S/N ratio, 10:1). Lys recoveries from fortified biological samples were >97.5%. Average Lys contents found in rumen fluid samples collected before the morning feeding and at 2.0,4.0, and 6.0 h after feeding were 4.26,3.34,3.58, and 3.82 μmol/L, respectively. The hydrolysate of a sample of mixed rumen microorganisms collected before the morning feeding was determined to contain 1.372 μmol/mg microbial nitrogen in the form of Lys. The Lys concentrations of human plasma, goat plasma, human urine, and goat urine were 140.0, 102.0,58.0, and 32.0 μmol/L, respectively.

scholarly journals Rapid Determination of Fosetyl-Aluminum Residues in Lettuce by Liquid Chromatography/Electrospray Tandem Mass Spectrometry

2003 ◽  
Vol 86 (4) ◽  
pp. 832-838 ◽  
Author(s):  
Félix Hernández ◽  
Juan V Sancho ◽  
Óscar J Pozo ◽  
Carme Villaplana ◽  
María Ibáñez ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
Tandem Mass Spectrometry ◽  
Limit Of Detection ◽  
Rapid Determination ◽  
Tandem Mass ◽  
Electrospray Tandem Mass Spectrometry ◽  
Relative Standard ◽  
Limit Of Quantitation

Abstract This paper describes a new method for the sensitive and selective determination of fosetyl-aluminum (Al) residues in vegetable samples. The method involves extraction with water by using a high-speed blender and subsequent injection of the 5-fold diluted extract into the liquid chromatograph. Fosetyl-Al is determined by liquid chromatography with electrospray tandem mass spectrometry after the addition of tetrabutylammonium acetate as the ion-pairing re-agent. The method has been used to assay lettuce samples spiked at 2 and 0.2 mg/kg. Recoveries were satisfactory, with mean values of 98 and 106%, respectively, and relative standard deviations were <10%. The limit of quantitation was 0.2 mg/kg, and the limit of detection was as low as 0.05 mg/kg. Matrix-matched calibration was used for quantitation, and the addition of an internal standard improved repeatability. The developed method allows the accurate and rapid determination of low levels of fosetyl-Al residues in lettuce with very little sample handling and good sensitivity; it was shown to be robust by the analysis of almost 100 samples.

Rapid determination of glutamine in biological samples by high-performance liquid chromatography

1993 ◽  
Vol 218 (2) ◽  
pp. 159-168 ◽  
Author(s):  
Tom Teerlink ◽  
Marcel W.T. Hennekes ◽  
Paul A.M. van Leeuwen ◽  
Alexander Houdijk
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Biological Samples ◽  
High Performance ◽  
Rapid Determination

scholarly journals Determination of 7B3 Residues in Cotton Plants by Liquid Chromatography/Mass Spectrometry

2009 ◽  
Vol 92 (1) ◽  
pp. 302-306 ◽  
Author(s):  
Xiao-Jing Yan ◽  
Xiao-Mei Liang ◽  
Yan-Jun Xu ◽  
Shu-Hui Jin ◽  
Dao-Quan Wang
Keyword(s):  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
Limit Of Detection ◽  
Reversed Phase ◽  
Liquid Chromatography Mass Spectrometry ◽  
Chromatography Mass Spectrometry ◽  
Relative Standard ◽  
Limit Of Quantitation ◽  
Cotton Plants

Abstract A method was developed for the determination of 7B3 (12-propyloxyimino-1,15-pentadecanlactam), a novel macrolactam fungicide, by liquid chromatography/mass spectrometry (LC/MS) with positive electrospray ionization (ESI+). The method used a reversed-phase C18 column and acetonitrilewater (60 + 40, v/v) mobile phase. The quick, easy, cheap, effective, rugged, and safe method was used for extraction of 7B3 from cotton plants, which involved the extraction of 10 g homogenized sample with 10 mL acetonitrile, followed by the addition of 4 g anhydrous MgSO4 and 1.0 g NaCl. After centrifugation, 1 mL of the buffered acetonitrile extract was transferred into a tube containing 50 mg primary secondary amine sorbent and 100 mg anhydrous MgSO4. After shaking and centrifugation, the final extract was transferred to an autosampler vial for concurrent analysis by LC/MS. The results of 7B3 determined by LC/MS in the selective ion monitoring mode were linear, and the matrix effect of the method was evaluated. The average recoveries of 7B3 fortified at different levels were within 84.1100.2, and the relative standard deviations were <7.5 for all samples analyzed. The method limit of detection and the limit of quantitation values were 0.03 and 0.1 mg/kg, respectively. The proposed method was successfully applied to determine 7B3 residues in practical samples. This method is sensitive, accurate, reliable, simple, and safe.

Determination of Mimosine and 2,3-Dihydroxypyridine in Leucaena leucocephala by Reversed Phase High-Performance Liquid Chromatography

2011 ◽  
Vol 140 ◽  
pp. 296-301 ◽  
Author(s):  
Cai Mei Wu ◽  
Hong Min Yuan ◽  
Gang Jia ◽  
Zhi Sheng Wang ◽  
Xiu Qun Wu
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Leucaena Leucocephala ◽  
High Performance ◽  
Limit Of Detection ◽  
Reversed Phase ◽  
Quantitative Detection ◽  
Uv Detector ◽  
Chromatography Method

A reversed high performance liquid chromatography method was developed for the quantitative determination of mimosine and 2,3-DHP in leaves ofLeucaena Leucocephala. Mimosine and 2,3DHP were extracted using 0.1N HCl.The chromatograph conditions were investigated and optimized. The optimal HPLC conditions as follows: Agilent HC-C18 column （4.6×150mm,5μm） was used at 30°C. The method used a variable wavelength UV detector at 280nm, the mobile phase consisted of 0.2 % (w/v) orthophosphoric acid and methanol, the gradient elution was adopted. The injection volume was 10μL. The linearity is favorable in the range of 1.0 to 50μg mL-1with a correlation coefficient of 0.99998 for mimosine and 0.99902 for 2,3DHP. Under the optimal conditions, the method limit of detection (LOD) of mimosine and 2,3DHP were 0.40mg/kg and 0.55mg/kg respectively. The recovery of mimosine was 87.00-94.70% with the RSD (n=5) of 2.75-3.81% in the spiked levels 0,1, 5, 20mg/g. At the same time, the recovery of 2,3DHP was 88-95.4% with the RSD (n=5) of 2.24-4.90%. The method was found to be simple, sensitive, fast and accurate, and has been applied successfully for the quantitative detection of mimosine and 2,3-DHP in leaves ofLeucaena Leucocephala, plasma and excretion of ruminant.

scholarly journals Determination of Cyclamate in Foods by Ultraperformance Liquid Chromatography/Tandem Mass Spectrometry

2008 ◽  
Vol 91 (5) ◽  
pp. 1095-1102 ◽  
Author(s):  
Robert Sheridan ◽  
Thomas King
Keyword(s):  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
Sample Preparation ◽  
Tandem Mass Spectrometry ◽  
Limit Of Detection ◽  
Tandem Mass ◽  
Chromatography Tandem Mass Spectrometry ◽  
Limit Of Quantitation ◽  
Liquid Chromatography Tandem Mass

Abstract A highly sensitive and selective method that requires minimal sample preparation was developed for the confirmation and quantitation of cyclamate in a variety of foods by high-performance liquid chromatography/tandem mass spectrometry (HPLC/MS/MS). Sample preparation consisted of homogenization followed by extraction and dilution of cyclamate with water. HPLC separation was achieved using a bridged ethyl hybrid C18 high-pressure column with a mobile phase consisting of 0.15 acetic acid and methanol. Under electrospray ionization negative conditions, quantitation was achieved by monitoring the fragment m/z 79.7 while also collecting parent ion m/z 177.9. Two food matrixes, diet soda and jelly, were subjected to a validation procedure in order to evaluate the applicability of the method. The cyclamate limit of detection for both matrixes was determined to be 0.050 g/g with a limit of quantitation of 0.150 g/g. The correlation coefficient of the calibration curves was >0.9998 from 0.0005 to 0.100 g/mL. The method has been used for the determination of cyclamate in several foods and the results are presented.

scholarly journals A Rapid Determination of Cinnarizine in Bulk and Pharmaceutical Dosage Form by LC

2010 ◽  
Vol 7 (3) ◽  
pp. 1080-1084 ◽  
Author(s):  
A. A. Heda ◽  
A. R. Sonawane ◽  
G. H. Naranje ◽  
P. K. Puranik
Keyword(s):  
Potassium Hydroxide ◽  
Dosage Form ◽  
Limit Of Detection ◽  
Rapid Determination ◽  
High Pressure Liquid Chromatographic ◽  
Pharmaceutical Dosage Form ◽  
Liquid Chromatographic Method ◽  
Limit Of Quantitation ◽  
Liquid Chromatographic

A simple, selective, rapid and precise reverse phase high pressure liquid chromatographic method has been developed for the estimation of cinnarizine from pharmaceutical formulation. The method was developed using MICRA-NPS C18(length×OD×ID =33×8.0×6.0 mm, 1.5 μm) column with a mobile phase consisting of acetonitrile, triethylamine buffer (adjusted to pH 4.5 with 10% w/v potassium hydroxide) and tetrahydrofuran in the ratio 30:66:4 respectively, at a flow rate of 0.5 mL/min. Wavelength was fixed at 253 nm. The developed method was validated for linearity, accuracy, precision, limit of detection and limit of quantitation. The proposed method can be used for the routine estimation of cinnarizine in pharmaceutical dosage form.

Determination of Nicarbazin in Chicken Tissues By Liquid Chromatography and Confirmation of Identity By Thermospray Liquid Chromatography/Mass Spectrometry

1989 ◽  
Vol 72 (4) ◽  
pp. 577-581 ◽  
Author(s):  
Jerry L Lewis ◽  
Thomas D Macy ◽  
Daniel A Garteiz
Keyword(s):  
Liquid Chromatography ◽  
Limit Of Detection ◽  
Negative Ion ◽  
Liver Fat ◽  
Spectrometric Analysis ◽  
Differential Pulse Polarography ◽  
Uv Detector ◽  
Detection Techniques ◽  
Chicken Tissues

Abstract A liquid chromatographic method is described for the quantitative measurement of nicarbazin in chicken liver, fat, muscle, and skin tissues. The 4,4'-dinitrocarbanilide (DNC) portion of nicarbazin is extracted from tissues with ethyl acetate. After filtration and evaporation, the extract is purified by liquid-liquid partitioning with acetonitrile-hexane and alumina cartridge chromatography. DNC is separated and measured by reverse-phase liquid chromatography (RPLC) with an octadecylsilyl (ODS) column and a UV detector set at 340 nm. The overall average recovery of DNC added to tissues was 83.4 ±3.1%. The lowest level validated in tissues by this procedure was 0.10 ppm. The limit of detection was estimated to be 0.020 ppm. This method provides a sensitive, selective, rapid, and reproducible alternative to existing purification, separation, and detection techniques, such as differential pulse polarography and colorimetry, for determination of nicarbazin in chicken tissues. Identity of DNC is confirmed by subjecting the purified extracts to thermospray-LC/mass spectrometric analysis using negative-ion detection and selected ion monitoring. Three structural-indicating ions at m/z 302,272, and 164 are monitored in the thermospray-mass spectrum which are characteristic of the DNC molecule.

scholarly journals Estimation of Atenolol by Reverse Phase High Performance Liquid Chromatography

2010 ◽  
Vol 7 (3) ◽  
pp. 962-966 ◽  
Author(s):  
Naveen Kumar ◽  
Nishant Verma ◽  
Omveer Songh ◽  
Naveen Joshi ◽  
Kanwar Gaurav Singh
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
High Performance ◽  
Limit Of Detection ◽  
Equal Proportion ◽  
Uv Detector ◽  
Chromatography Method ◽  
Relative Standard ◽  
Limit Of Quantitation ◽  
Liquid Chromatography Method

A simple, precise, sensitive, fast and accurate high performance liquid chromatography method has been developed for the determination of atenolol using mixture of phosphate buffer and acetonitrile (53:47 v/v) as mobile phase. Buffer was prepared by mixing 0.02 M K2PO4and 0.003 M KH2PO4in equal proportion. Detection was carried out using UV detector at λmax230 nm. Column was ODS and dimensions of column was 25 mm × 4.6 mm. Atenolol was eluted out at retention time of 2.1 min. Method was validated at 1.2 mL/min flow rate. Calibration curve was linear between ranges of 40 to 200 mcg concentration. The limit of detection was calculates 120 nano gram and limit of quantitation is 510 nano gram. The relative standard deviation (RSD) of atenolol was 0.6. The percentage recovery of atenolol was 99.6%.

scholarly journals Analysis of Ethyl p-Methoxycinnamate from Kaempferia galanga L. Extract by High Performance Liquid Chromatography

2021 ◽  
Vol 5 (4) ◽  
pp. 353-358
Author(s):  
Wiwin Winingsih ◽  
Sri Gustini Husein ◽  
Rozalia Putri Neno Ramdhani
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
High Performance ◽  
Limit Of Detection ◽  
Range Limit ◽  
Uv Detector ◽  
Kaempferia Galanga ◽  
System Suitability ◽  
Relative Standard ◽  
Limit Of Quantitation

Ethyl para-methoxycinamate (EPMS) is a major compound of Kaempferia galanga L that has anti-inflammatory effect.  The purpose of this study was to determine of EPMS in Kaempferiae galanga L rhizome extract by  High Performance Liquid Chromatography (HPLC) and evaluated the performance of the analysis. This study included determination of system suitability, accuracy, precision, linearity and range, limit of detection (LOD) and Limit of quantitation (LOQ) and selectivity.  The results of system suitability test  HPLC System for EPMS analysis were as follows isocratic elution system of a mobile phase mixture of methanol: water (70:30) containing 0.1% TFA, uv detector at a wavelength of 308 nm using column C18 (150 × 4, 6mm, 5μm) flow rate 1 ml / min. From the analysis, it was found that the average EPMS content was 78.74%. Then method had linear concentration range from 5-360 ppm, with R ² = 0.9999. The LOD and LOQ were 7.0722 ppm and 21.4311 ppm respectively. The accuracy of this method that represented by % recovery was 98.02% - 101.26%. The precision of this method that expressed by Relative Standard Deviation (RSD) was 1.57%. The selectivity of this method that showed by  resolution value was 2.6. Based on the results of the system suitability test and analysis performance evaluation,all parameters met the requirements.

scholarly journals Determination of Aflatoxin B1 in Feedstuffs without Clean-Up Step by High-Performance Liquid Chromatography

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Sasiprapa Choochuay ◽  
Jutamas Phakam ◽  
Prakorn Jala ◽  
Thanapoom Maneeboon ◽  
Natthasit Tansakul
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
High Performance ◽  
Limit Of Detection ◽  
Precolumn Derivatization ◽  
Broken Rice ◽  
Relative Standard ◽  
Limit Of Quantitation ◽  
Aflatoxin B

A reliable and rapid method has been developed for the determination of aflatoxin B1 (AFB1) in four kinds of feedstuffs comprising broken rice, peanuts, corn, and fishmeal. A sample preparation was carried out based on the QuEChERS method with the exclusion of the clean-up step. In this study, AFB1 was extracted using acetonitrile/methanol (40/60 v/v), followed by partitioning with sodium chloride and magnesium sulfate. High-performance liquid chromatography with precolumn derivatization and fluorescence detection was performed. The coefficients of determination were greater than 0.9800. Throughout the developed method, the recovery of all feedstuffs achieved a range of 82.50-109.85% with relative standard deviation lower than 11% for all analytes at a concentration of 20-100 ng/g. The limit of detection (LOD) ranged from 0.2 to 1.2 ng/g and limit of quantitation (LOQ) ranged from 0.3 to 1.5 ng/g. The validated method was successfully applied to a total of 120 samples. The occurrence of AFB1 contamination was found at the following concentrations: in broken rice (0.44-2.33ng/g), peanut (3.97-106.26ng/g), corn (0.88-50.29 ng/g), and fishmeal (1.06-10.35 ng/g). These results indicate that the proposed method may be useful for regularly monitoring AFB1 contamination in feedstuffs.

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