scholarly journals An Optimized High Throughput Clean-Up Method Using Mixed-Mode SPE Plate for the Analysis of Free Arachidonic Acid in Plasma by LC-MS/MS

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Wan Wang ◽  
Suzi Qin ◽  
Linsen Li ◽  
Xiaohua Chen ◽  
Qunjie Wang ◽  
...  
Keyword(s):  
Arachidonic Acid ◽  
High Throughput ◽  
Mixed Mode ◽  
Preparation Method ◽  
Limit Of Detection ◽  
Solid Phase ◽  
Multiple Reaction Monitoring ◽  
Reversed Phase ◽  
Free Arachidonic Acid

A high throughput sample preparation method was developed utilizing mixed-mode solid phase extraction (SPE) in 96-well plate format for the determination of free arachidonic acid in plasma by LC-MS/MS. Plasma was mixed with 3% aqueous ammonia and loaded into each well of 96-well plate. After washing with water and methanol sequentially, 3% of formic acid in acetonitrile was used to elute arachidonic acid. The collected fraction was injected onto a reversed phase column at 30°C with mobile phase of acetonitrile/water (70 : 30, v/v) and detected by LC-MS/MS coupled with electrospray ionization (ESI) in multiple reaction monitoring (MRM) mode. The calibration curve ranged from 10 to 2500 ng/mL with sufficient linearity (r2= 0.9999). The recoveries were in the range of 99.38% to 103.21% with RSD less than 6%. The limit of detection is 3 ng/mL.

scholarly journals Determination of Vitamin K1 in Medical Foods by Liquid Chromatography with Postcolumn Reduction and Fluorometric Detection

2000 ◽  
Vol 83 (4) ◽  
pp. 957-962 ◽  
Author(s):  
George M Ware ◽  
G William Chase ◽  
Ronald R Eitenmiller ◽  
Austin R Long
Keyword(s):  
Limit Of Detection ◽  
Solid Phase ◽  
Sodium Bicarbonate Solution ◽  
Reversed Phase ◽  
Mean Value ◽  
Fluorometric Detection ◽  
Vitamin K1 ◽  
Limit Of Quantitation ◽  
Medical Foods

Abstract A liquid chromatographic (LC) method is described for the determination of vitamin K1 in medical foods. The sample is enzymatically digested with lipase and α-amylase and extracted with 1% sodium bicarbonate solution–isopropanol (1 + 1). After C18 solid-phase extraction, vitamin K1 is separated by nonaqueous reversed-phase LC, converted to the hydroquinone by postcolumn zinc reduction, and quantitated by fluorescence detection. The limit of detection is 8 pg (3 σ), and the limit of quantitation is 27 pg (10 σ) on column. Linear response ranged from 0.1 to 1.0 ng vitamin K1 (r = 0.9999). The mean recovery (n = 38) for all spiking levels was 101.6 ± 2.85%. Analysis of Standard Reference Material 1846, Infant Formula, gave a mean value of 0.95 ± 0.088 mg vitamin K/kg (K or K1?)(n = 31) with a coefficient of variation of 9.26.

Detection of trace amounts of abamectin used as an antiparasitic agent in fallow deer tissues

2009 ◽  
Vol 57 (1) ◽  
pp. 99-107 ◽  
Author(s):  
Diana Žele ◽  
Silvestra Kobal ◽  
Gorazd Vengušt ◽  
Andrej Bidovec ◽  
Anton Vengušt ◽  
...  
Keyword(s):  
High Performance ◽  
Limit Of Detection ◽  
Solid Phase ◽  
Fallow Deer ◽  
Reversed Phase ◽  
Fat Tissue ◽  
Matrix Interference ◽  
Solid Phase Extraction Cartridge ◽  
Tissue Matrix

A sensitive and reliable method for the determination of trace amounts of abamectin in muscles, kidneys and fat tissue of fallow deer is presented. Abamectin was extracted from the tissues with acetonitrile and the extract was cleaned up on a C8 solid-phase extraction cartridge. Abamectin residue was derivatised with trifluoroacetic acid anhydride and 1-methylimidazole, and determined using reversed- phase high-performance liquid chromatography under isocratic conditions and fluorescence detection. The recoveries of the method were high and consistent, ranging from 78% to 90%. The limit of detection of the method was below 1 μg/kg when analysing muscle, kidney and fat tissue. Matrix-matched calibration was used in order to obtain accurate values and to avoid matrix interference.

scholarly journals Determination of Pharmaceutical Residues by UPLC-MS/MS Method: Validation and Application on Surface Water and Hospital Wastewater

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Bui Van Hoi ◽  
Cam-Tu Vu ◽  
Lan-Anh Phung-Thi ◽  
Thao Thi Nguyen ◽  
Phuong Thanh Nguyen ◽  
...  
Keyword(s):  
Surface Water ◽  
Analytical Method ◽  
Limit Of Detection ◽  
Solid Phase ◽  
Multiple Reaction Monitoring ◽  
Hospital Wastewater ◽  
Esi Ms ◽  
Pharmaceutical Residues ◽  
Detection Frequency

In this study, an analytical method for the simultaneous determination of 7 major pharmaceutical residues in Vietnam, namely, carbamazepine, ciprofloxacin, ofloxacin, ketoprofen, paracetamol, sulfamethoxazole, and trimethoprim, in surface water and hospital wastewater has been developed. The method includes enrichment and clean-up steps by solid phase extraction using mix-mode cation exchange, followed by identification and quantification using an ultrahigh-performance liquid chromatography and tandem mass spectrometry and employing electrospray ionization (UPLC-ESI-MS/MS). Seven target compounds were separated on the reversed phase column and detected in multiple reaction monitoring (MRM) mode within 6 minutes. The present study also optimized the operating parameters of the mass spectrometer to achieve the highest analytical signals for all target compounds. All characteristic parameters of the analytical method were investigated, including linearity range, limit of detection, limit of quantification, precision, and accuracy. The important parameter in UPLC-ESI-MS/MS, matrix effect, was assessed and implemented via preextraction and postextraction spiking experiments. The overall recoveries of all target compounds were in the ranges from 55% to 109% and 56 % to 115% for surface water and hospital wastewater, respectively. Detection limits for surface water and hospital wastewater were 0.005–0.015 µg L−1 and 0.014–0.123 µg L−1, respectively. The sensitivity of the developed method was allowed for determination of target compounds at trace level in environmental water samples. The in-house validation of the developed method was performed by spiking experiment in both the surface water and hospital wastewater matrix. The method was then applied to analyze several surface water and hospital wastewater samples taken from West Lake and some hospitals in Vietnam, where the level of these pharmaceutical product residues was still missed. Sulfamethoxazole was present at a high detection frequency in both surface water (33% of analyzed samples) and hospital wastewater (81% of analyzed samples) samples.

Simultaneous determination of aflatoxin B1, aflatoxin B2, mycophenolic acid and sterigmatocystin in grape pomace by UHPLC-MS/MS

2014 ◽  
Vol 7 (2) ◽  
pp. 121-129 ◽  
Author(s):  
L. Luan ◽  
N. Chen ◽  
Z. Han ◽  
X. Liu ◽  
Y. Zheng ◽  
...  
Keyword(s):  
Simultaneous Determination ◽  
Mycophenolic Acid ◽  
Solid Phase ◽  
Multiple Reaction Monitoring ◽  
Reversed Phase ◽  
Grape Pomace ◽  
Relative Standard ◽  
Ultrahigh Performance Liquid Chromatography ◽  
Aflatoxin B

A reliable ultrahigh performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method was developed for the simultaneous determination of aflatoxin B1, aflatoxin B2, mycophenolic acid and sterigmatocystin in grape pomace. The samples were extracted by acetonitrile aqueous solution and further purified using a solid-phase extraction-based homemade clean-up cartridge. Next, the analytes were separated on a reversed-phase C18 column with a mobile phase consisting of water and acetonitrile. The separated compounds were detected with a tandem quadrupole mass spectrometer operating in positive electro-spray ionisation mode using multiple reaction monitoring. The established method was extensively validated by determining linearity (R2≯0.999), recovery (97.5-102.8%) and precision (relative standard deviation ≤7.0%). This method was then used for the simultaneous determination of the four mycotoxins in grape pomace samples.

Liquid Chromatographic Method for Rapid Determination of Total Avermectin B1 and 8,9-Z-Avermectin B1 Residues in Apples

1995 ◽  
Vol 78 (2) ◽  
pp. 419-422 ◽  
Author(s):  
Janice A Cobin ◽  
Nelson A Johnson
Keyword(s):  
Chromatographic Method ◽  
Limit Of Detection ◽  
Solid Phase ◽  
Rapid Determination ◽  
Reversed Phase ◽  
Extraction Column ◽  
Liquid Chromatographic Method ◽  
Limit Of Quantitation ◽  
Liquid Chromatographic

Abstract A liquid chromatographic method has been developed and validated for the rapid determination of avermectin B1 and 8,9-Z-avermectin B1 residues in apples. The avermectins are extracted from the crop matrix with an acetonitrile–water–hexane mixture; the extract is cleaned up on an aminopropyl solid-phase extraction column. The avermectins are derivatized with trifluoroacetic anhydride and analyzed by reversed-phase liquid chromatography with fluorescence detection. Recoveries of avermectins from apples fortified with about 2–77 ppb avermectin B1a or 2-27 ppb 8,9-Z-avermectin B1a averaged 85%. The limit of quantitation is 2 ppb (signal- to-noise [S/N] ratio, 12) and the limit of detection is 1 ppb (S/N ratio, 6) for each analyte. The assay is a simple, rapid, and sensitive method for monitoring the total amount of avermectin residues in apples.

scholarly journals Determination of Total Avermectin B1 and 8,9-Z-Avermectin B1 Residues in Wine by Liquid Chromatography

1996 ◽  
Vol 79 (5) ◽  
pp. 1158-1161 ◽  
Author(s):  
Janice A Cobin ◽  
Nelson A Johnson
Keyword(s):  
Liquid Chromatography ◽  
Limit Of Detection ◽  
Solid Phase ◽  
Signal To Noise Ratio ◽  
Reversed Phase ◽  
Liquid Chromatographic Method ◽  
Limit Of Quantitation ◽  
Phase Liquid ◽  
Liquid Chromatographic

Abstract A liquid chromatographic method was developed and validated for determination of avermectin Bi and 8,9-Z-avermectin B1 residues in wine. The sample is extracted with hexane-acetonitrile and the hexane layer containing the avermectins is concentrated/ purified on an aminopropyl solid-phase extraction (SPE) column. The purified extract is derivatized with trifluoroacetic anhydride and the derivatized avermectins are analyzed by reversed-phase liquid chromatography with fluorescence detection. Recoveries of avermectins from wine fortified with approximately 1-25 ng/g avermectin B1a or 8,9-Zavermectin B1a averaged 88 and 102%, respectively. The limit of quantitation is 1 ng/g (signal-to-noise ratio [S/N] > 10) and the limit of detection is 0.5 ng/g (S/N > 3) for each analyte. This procedure provides a simple, rapid, and sensitive method for monitoring the total amount of avermectin residues in wine.

scholarly journals Determination of Tranquilizers in Swine Urine by Ultra-High-Performance Liquid Chromatography-Tandem Mass Spectrometry

Molecules ◽  
2018 ◽  
Vol 23 (12) ◽  
pp. 3215 ◽  
Author(s):  
Yingyu Wang ◽  
Xiaowei Li ◽  
Yuebin Ke ◽  
Chengfei Wang ◽  
Yuan Zhang ◽  
...  
Keyword(s):  
High Performance ◽  
Solid Phase ◽  
Multiple Reaction Monitoring ◽  
Gradient Elution ◽  
Reversed Phase ◽  
Single Step ◽  
Swine Urine ◽  
Relative Standard ◽  
Positive Mode

A rapid, reliable, and sensitive method was developed for the determination of ten tranquilizers in swine urine. Sample preparation was based on solid-phase extraction, which combined isolation of the compounds and sample cleanup in a single step. Separation was performed on a reversed phase C18 column by gradient elution with a chromatographic run time of seven minutes, consisting of 0.1% formic acid in water and acetonitrile as the mobile phase. Multiple reaction monitoring in positive mode was applied for data acquisition. Matrix-matched calibration was used for quantification and good linearity was obtained with coefficients of determination higher than 0.99. The average recoveries of fortified samples at concentrations between 0.05 and 10 µg/L ranged from 85% to 106% with interday relative standard deviations of less than 13% in all cases. The limits of detection and limits of quantification obtained for tranquilizers in the urine were in the ranges of 0.03–0.1 µg/L and 0.05–0.25 µg/L, respectively. The applicability of the proposed method was demonstrated by analyzing real samples; diazepam was detected at concentrations between 0.3 and 0.6 μg/L.

scholarly journals Mixed-Mode Solid-Phase Extraction and Cleanup Procedures for the Liquid Chromatographic Determination of Thiabendazole and Carbendazim in Fruit Juices

2001 ◽  
Vol 84 (2) ◽  
pp. 556-562 ◽  
Author(s):  
Michael S Young ◽  
Dorothy J Phillips ◽  
Pamela C Iraneta ◽  
Jim Krol
Keyword(s):  
Solid Phase Extraction ◽  
Cation Exchange ◽  
Mixed Mode ◽  
Solid Phase ◽  
Chromatographic Determination ◽  
Reversed Phase ◽  
Phase Extraction ◽  
Grape Juices ◽  
Liquid Chromatographic

Abstract Solid-phase extraction (SPE) procedures were developed for rapid cleanup and determination of thiabendazole and carbendazim in orange, apple, and grape juices. Samples were prepared by using an SPE cartridge containing a mixed-mode sorbent with both reversed-phase and strong cation-exchange chemistries. Analysis was by liquid chromatography with photodiode-array UV detection. Orange juice was analyzed by mixed-mode cation-exchange extraction with reversed-phase cleanup; the other juices were analyzed by reversed-phase extraction with cation-exchange cleanup. Recoveries >80% for carbendazim and >90% for thiabendazole. Quantitation limits were 20 μg/L for both analytes.

scholarly journals Determination of Chlorpromazine, Haloperidol, Levomepromazine, Olanzapine, Risperidone, and Sulpiride in Human Plasma by Liquid Chromatography/Tandem Mass Spectrometry (LC-MS/MS)

2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
Abderrezak Khelfi ◽  
Mohammed Azzouz ◽  
Rania Abtroun ◽  
Mohammed Reggabi ◽  
Berkahoum Alamir
Keyword(s):  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
Tandem Mass Spectrometry ◽  
High Performance ◽  
Solid Phase ◽  
Multiple Reaction Monitoring ◽  
Reversed Phase ◽  
Tandem Mass ◽  
Plasma Samples

Background and Objective. In this study, turbo-ion spray as an interface of tandem mass spectrometry (MS/MS) was performed for sensitive and accurate quantification of chlorpromazine, haloperidol, levomepromazine, olanzapine, risperidone, and sulpiride in plasma samples. Methods. Separation was performed by gradient reversed phase high-performance liquid chromatography using a mobile phase containing ammonium formiate 2 mM, pH 2.7, and acetonitrile flowing through a Restek PFP Propyl C18 analytical column (50 mm×2.1 mm i.d.) with particle size of 5 µm, at a flow rate of 800 µL/min. Positive ion fragments were detected in multiple reaction monitoring (MRM) mode. Sample preparation was achieved by solid phase extraction (SPE) (Oasis HLB). Results. Mean extraction recoveries ranged from 82.75% to 100.96%. The standard calibration curves showed an excellent linearity, covering subtherapeutic, therapeutic, and toxic ranges. Intraday and interday validation using quality control (QC) samples were performed. The inaccuracy and imprecision were below 12% at all concentration levels. The limits of detection (LOD) and quantification (LOQ) for all analytes were under therapeutic ranges for all tested analytes. Thus, the proposed method was sensitive enough for the detection and determination of subtherapeutic levels of these antipsychotics in plasma samples. No interference of endogenous or exogenous molecules was observed and no carryover effects were recorded. Conclusion. According to the results, the proposed method is simple, specific, linear, accurate, and precise and can be applied for antipsychotic analysis in clinical routine. This method was applied for the determination of the tested antipsychotics in plasma samples taken from 71 individuals.

scholarly journals Development and Validation of a Reversed-Phase Liquid Chromatography Method for the Simultaneous Determination of Indole-3-Acetic Acid, Indole-3-Pyruvic Acid, and Abscisic Acid in Barley (Hordeum vulgareL.)

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Ilva Nakurte ◽  
Anete Keisa ◽  
Nils Rostoks
Keyword(s):  
Acetic Acid ◽  
Abscisic Acid ◽  
Liquid Chromatography ◽  
Pyruvic Acid ◽  
Limit Of Detection ◽  
Solid Phase ◽  
Reversed Phase ◽  
Validation Parameters ◽  
Indole 3 Acetic Acid

A simple, sensitive, precise, and specific reverse HPLC method was developed and validated for the determination of plant hormones in barley (Hordeum vulgareL.). The method includes extraction in aqueous organic solvent followed by solid-phase extraction, sample evaporation, and reversed-phase HPLC analysis in a general purpose UV-visible (abscisic acid (ABA)) and fluorescence detection (indole-3-acetic acid (IAA) and indole-3-pyruvic acid (IPA)), high-performance liquid chromatography system. The separation was carried out on Zorbax Eclipse XDB C8 column (150 × 4.6 mm I.D) with a mobile phase composed of methanol and 1% acetic acid (60 : 40 v/v) in isocratic mode at a flow rate of 1 ml min-1. The detection was monitored at 270 nm (ABA) and at 282 nm (Ex) and 360 nm (Em) (IAA, IPA). The developed method was validated in terms of accuracy, precision, linearity, limit of detection, limit of quantification, and robustness. The determined validation parameters are in the commonly acceptable ranges for that kind of analysis.

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