Isolation, method development, and validation of diterpenes in coffee oil: identification by multiple reaction monitoring approach with atmospheric pressure chemical ionization mode

2021 ◽  
Vol 13 (1) ◽  
pp. 42
Author(s):  
Naveen Puttaswamy ◽  
LingarajuHarakanahalli Basavegowda ◽  
Deepak Machettira ◽  
Chandrappa Siddappa ◽  
Rashmi Ramesh ◽  
...  
Keyword(s):  
Atmospheric Pressure ◽  
Method Development ◽  
Atmospheric Pressure Chemical Ionization ◽  
Multiple Reaction Monitoring ◽  
Pressure Chemical Ionization ◽  
Pressure Chemical ◽  
Method Development And Validation ◽  
Ionization Mode ◽  
Coffee Oil ◽  
Development And Validation

Determination of Total Nitrofuran Metabolites in Shrimp Muscle Using Liquid Chromatography/Tandem Mass Spectrometry in the Atmospheric Pressure Chemical Ionization Mode

2012 ◽  
Vol 95 (4) ◽  
pp. 1222-1233 ◽  
Author(s):  
Haejung An ◽  
Mark Henry ◽  
Teresa Cain ◽  
Bichsa Tran ◽  
Han Chol Paek ◽  
...  
Keyword(s):  
Atmospheric Pressure ◽  
Chemical Ionization ◽  
Atmospheric Pressure Chemical Ionization ◽  
Liquid Chromatography Tandem Mass ◽  
Pressure Chemical Ionization ◽  
Pressure Chemical ◽  
Ionization Mode ◽  
Extraction Processes ◽  
Nitrofuran Metabolites

Abstract The method of MacMahon and Lohne for analysis of nitrofuran metabolites in shrimp was optimized to streamline the extraction processes and the LC analysis. This revised method includes 16 h of mild acid hydrolysis/derivatization followed by ethyl acetate extraction and analysis by LC/MS/MS in the atmospheric pressure chemical ionization mode. This revised method was validated in shrimp for concentrations of 0.25 to 2.0 ng/g. The LOQ was 0.25 ng/g for all metabolites. The LOD was 0.052 ng/g for 1-aminohydantoin (AHD), 0.206 ng/g for 3-amino-2-oxazolidinone (AOZ), 0.108 ng/g for semicarbazide (SC), and 0.062 ng/g for 3-amino-5-morpholinomethyl-2-oxazolidinone (AMOZ). The spike recoveries with RSD into negative matrix at 1 ng/g were 100.2% (3.2%) for AHD, 102.5% (1.0%) for AOZ, 103.7% (2.3%) for SC, and 104.0% (3.3%) for AMOZ. The spike recoveries at 1 ng/g into unknown samples (n = 108) containing varied levels of nitrofuran metabolites were 112.6% (25.7%) for AHD, 108.1% (12.1%) for AOZ, 103.0% (12.0%) for SC, and 100.3% (6.9%) for AMOZ. Interday precision with samples containing incurred AOZ concentrations of 0.92 to 17.8 ppb performed over a year was 10.4% RSD. The method is accurate and precise for determining nitrofuran concentrations in the edible tissue of shrimp.

scholarly journals Simultaneous Quantitation of S(+)- and R(−)-Baclofen and Its Metabolite in Human Plasma and Cerebrospinal Fluid using LC–APCI–MS/MS: An Application for Clinical Studies

Molecules ◽  
2020 ◽  
Vol 25 (2) ◽  
pp. 250
Author(s):  
Qingfeng He ◽  
Yashpal S. Chhonker ◽  
Matthew J. McLaughlin ◽  
Daryl J. Murry
Keyword(s):  
Human Plasma ◽  
Atmospheric Pressure ◽  
Atmospheric Pressure Chemical Ionization ◽  
Multiple Reaction Monitoring ◽  
Optimal Dose ◽  
Racemic Mixture ◽  
Hydroxybutyric Acid ◽  
Pressure Chemical Ionization ◽  
Pressure Chemical ◽  
Acid Metabolites

Baclofen is a racemic mixture that is commonly used for the treatment for spasticity. However, the optimal dose and dosing interval to achieve effective cerebral spinal fluid (CSF) concentrations of baclofen are not known. Moreover, it is unclear if there are differences in the ability of R- or S-baclofen to cross the blood–brain barrier and achieve effective CSF concentrations. We have validated a liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) method with improved selectivity and sensitivity for the simultaneous quantitation of R- and S-baclofen and metabolites in plasma and CSF. Protein precipitation by acetonitrile was utilized to obtain an acceptable recovery of the analytes. The detection and separation of analytes was achieved on a 48 °C-heated Crownpak CR(+) column (150 mm × 4.0 mm, 5μ) with elution using 0.4% formic acid (FA) in water and 0.4% FA in acetonitrile as the mobile phase running at a flow rate of 1.0 mL/min. Accurate quantitation was assured by using this MS/MS method with atmospheric pressure chemical ionization in multiple reaction monitoring (MRM) mode. Therefore, this method is enantioselective, accurate, precise, sensitive, reliable, and linear from 1 to 1500 ng/mL for baclofen and 2 to 4000 ng/mL for the metabolites. An additional method was developed to separate racemic baclofen 3-(4-chlorophenyl)-4 hydroxybutyric acid metabolites for individual concentration determination. Both validated methods were successfully applied to a clinical pharmacokinetic human plasma and CSF study evaluating the disposition of baclofen and metabolites.

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