A sensitive quantitative assay for the determination of propafenone and two metabolites, 5-hydroxypropafenone and N- depropylpropafenone, in human K2EDTA plasma using LC-MS/MS with ESI operated in positive mode

2017 ◽  
Vol 31 (10) ◽  
pp. e3967 ◽  
Author(s):  
Harilal Patel ◽  
Ashok Ghoghari ◽  
Chandrakant Bhatt ◽  
Shaival Shah ◽  
Anilkumar Jha ◽  
...  
2020 ◽  
Vol 44 (6) ◽  
pp. 580-588
Author(s):  
A López-Rabuñal ◽  
E Lendoiro ◽  
M Concheiro ◽  
M López-Rivadulla ◽  
A Cruz ◽  
...  

Abstract An LC–MS-MS method for the determination of 14 benzodiazepines (BZDs) (alprazolam, α-hydroxyalprazolam, clonazepam, bromazepam, diazepam, nordiazepam, lorazepam, lormetazepam, oxazepam, flunitrazepam, 7-aminoflunitrazepam, triazolam, midazolam and zolpidem) and 15 antidepressants (ADs) (amitriptyline, nortriptyline, imipramine, desipramine, clomipramine, norclomipramine, fluoxetine, norfluoxetine, sertraline, norsertraline, paroxetine, venlafaxine, desmethylvenlafaxine, citalopram and desmethylcitalopram) in meconium was developed and validated. Meconium samples (0.25 ± 0.02 g) were homogenized in methanol and subjected to mixed-mode cation exchange solid-phase extraction. Chromatographic separation was performed in reversed phase, with a gradient of 0.1% formic acid in 2 mM ammonium formate and acetonitrile. Two different chromatographic gradient methods were employed, one for the separation of ADs and another for BZDs. Analytes were monitored by tandem mass spectrometry employing electrospray positive mode in MRM mode (2 transitions per compound). Method validation included: linearity [n = 5, limit of quantification (LOQ) to 400 ng/g], limits of detection (n = 6, 1–20 ng/g), LOQ (n = 9, 5–20 ng/g), selectivity (no endogenous or exogenous interferences), accuracy (n = 15, 90.6–111.5%), imprecision (n = 15, 0–14.6%), matrix effect (n = 10, −73 to 194.9%), extraction efficiency (n = 6, 35.9–91.2%), process efficiency (n = 6, 20.1–188.2%), stability 72 h in the autosampler (n = 3, −8.5 to 9%) and freeze/thaw stability (n = 3, −1.2 to −47%). The method was applied to four meconium specimens, which were analyzed with and without hydrolysis (enzymatic and alkaline). The authentic meconium samples tested positive for alprazolam, α-hydroxyalprazolam, clonazepam, diazepam, nordiazepam, fluoxetine, norfluoxetine, clomipramine and norclomipramine. Therefore, the present LC–MS-MS method allows a high throughput determination of the most common BZDs and ADs in meconium, which could be useful in clinical and forensic settings.


1990 ◽  
Vol 12 (3-4) ◽  
pp. 183-187 ◽  
Author(s):  
Christina C. Evrall ◽  
Richard W. Attwell ◽  
Christopher A. Smith

Author(s):  
Suleman S. Khoja ◽  
Laxman J. Patel

Ertugliflozin and Sitagliptin is combination of Antidiabetic drug in tablet Steglujan 15 mg/100 mg film-coated tablets®, a member Antidiabetic drug, is a recent drug developed by Merck Sharp and Dohme Company for the treatment of Type 2 diabetes. Ertugliflozin and Sitagliptin can be used alone or in combination therapy. A highly sensitive, precise and accurate Liquid Chromatography with mass spectrometry (LC-MS/MS) method is developed and validated for the determination of Ertugliflozin and Sitagliptin in combined formulation. Chromatographic separation was carried out on Phenomenex Gemini, C18, (150 × 4.6 mm,5 μm) column. Isocratic method was based on 0.1% formic acid: acetonitrile (10:90, v/vas mobile phase, column temperature at 40°C and flow rate at 0.6 mL/minuteswere utilized. The mass spectrometer was operated under multiple reactions monitoring (MRM) mode using electrospray ionization by monitoring the transition pair (precursor to product ion) of m/z 437.10-328.95in the positive mode for Ertugliflozin and transition pair (precursor to product ion) of m/z 408.10-234.95 in the positive mode for Sitagliptin. The method was found linear in the concentration range of 15 to 450 ng/mL and 100–3000 ng/mL for Ertugliflozin and Sitagliptin respectively. The optimized method was validated according to the International Conference on Harmonization (ICH) and FDA guidelines. The developed method was found suitable for the quantitation of Ertugliflozin and Sitagliptin in Pharmaceutical dosage form.


1964 ◽  
Vol 10 (12) ◽  
pp. 1105-1111 ◽  
Author(s):  
Donald J Moore ◽  
Robert F Labbe

Abstract A procedure has been developed for the rapid, quantitative determination of urinary porphobilinogen. Interfering substances are removed by selectively adsorbing the porphobilinogen with an ion-exchange resin using a batch method. After acid elution of the porphobilinogen, Ehrlich's reagent is added to produce the chromophore, which is then measured spectrophotometrically. Obtaining absorption at two wavelengths permits a differentiation of porphobilinogen from interfering reactants not removed by the resin treatment. This assay is relatively simple, dependable, highly reproducible for increased amounts, and more specific than the qualitative assay.


1969 ◽  
Vol 15 (6) ◽  
pp. 505-508 ◽  
Author(s):  
Martin Semar ◽  
Gerhard Treser ◽  
Kurt Lange

Abstract A quantitative assay for the determination of fluorescence of tissue sections stained with fluorescein-labeled antibodies using a fluorometer is described. Sequential microtome sections were stained with labeled antiserums, washed repeatedly with buffered saline, and digested with 20% (w/v) NaOH at 60° for 12 hr. The fluorescence of the resultant solution is then read in a fluorometer. There is similarity between sequential sections of the same biopsy specimen. Specific blocking procedures reduce the readings of the fluorescence markedly. By comparison with values obtained simultaneously from standard curves of the labeled antiserums used, the amount of bound antibody or specific proteins can be determined quantitatively.


INDIAN DRUGS ◽  
2020 ◽  
Vol 57 (06) ◽  
pp. 32-38
Author(s):  
H. Potluri ◽  

A specific and sensitive method of liquid chromatography–tandem mass spectrometry was demonstrated for the experimental determination of venetoclax in human plasma utilising venetoclax-D8 as an internal standard. The column Xbridge C18, 50 × 4.6mm, 5 µm was used for attaining chromatographic separation by utilising 10mM ammonium formate and methanol as isocratic mobile phase in the composition ratio of 20:80 (V/V). The flow-rate selected was 0.7ml/min. Venetoclax and venetoclax-D8 are identified in multiple reaction monitoring (MRM) positive mode with proton adducts at m/z 869.53 →553.21 and m/z 877.14 → 553.23, respectively. For the successful extraction of drug as well as internal standard, liquid-liquid extraction technique was efficiently utilised. The developed technique was established in a linear concentration range of 5.0-5000.0 pg/ml along with correlation coefficient (r2) of 0.9994. Intra and inter-day precisions were found to be 0.7 to 1.90% and 0.7 to 2.0 % for venetoclax and venetoclax-D8, respectively. Accuracy was found to be within 98.6 to 101.99% and 99.17 to 101.14 % for venetoclax and venetoclax-D8, respectively. It was observed that throughout the bench top studies, post-operative stability studies and freeze-thawing cycles, venetoclax retained stability.


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