A proposal for comparing methods of quantitative analysis of endogenous compounds in biological systems by using the relative lower limit of quantification (rLLOQ)

2009 ◽  
Vol 877 (23) ◽  
pp. 2244-2251 ◽  
Author(s):  
Dimitrios Tsikas
Keyword(s):  
Quantitative Analysis ◽  
Lower Limit ◽  
Biological Systems ◽  
Limit Of Quantification ◽  
Endogenous Compounds

Eco-Friendly Green Liquid Chromatographic Separations of a Novel Combination of Azelastine and Fluticasone in the Presence of their Pharmaceutical Dosage form Additives

2020 ◽  
Vol 16 (3) ◽  
pp. 277-286
Author(s):  
Amal A. El-Masry ◽  
Mohammed E. A. Hammouda ◽  
Dalia R. El-Wasseef ◽  
Saadia M. El-Ashry
Keyword(s):  
Lower Limit ◽  
Dosage Form ◽  
Limit Of Detection ◽  
Sodium Dodecyl ◽  
Uv Detection ◽  
Simultaneous Estimation ◽  
Limit Of Quantification ◽  
Chromatographic Separations ◽  
Pharmaceutical Dosage Form ◽  
Liquid Chromatographic

Background: The first highly sensitive, rapid and specific green microemulsion liquid chromatographic (MELC) method was established for the simultaneous estimation of fluticasone propionate (FLU) and azelastine HCl (AZL) in the presence of their pharmaceutical dosage form additives (phenylethyl alcohol (PEA) and benzalkonium chloride (BNZ)). Methods: The separation was performed on a C18 column using (o/w) microemulsion as a mobile phase which contains 0.2 M sodium dodecyl sulphate (SDS) as surfactant, 10% butanol as cosurfactant, 1% n-octanol as internal phase and 0.3% triethylamine (TEA) adjusted at pH 6 by 0.02 M phosphoric acid; with UV detection at 220 nm and programmed with flow rate of 1 mL/min. Results: The validation characteristics e.g. linearity, lower limit of quantification (LOQ), lower limit of detection (LOD), accuracy, precision, robustness and specificity were investigated. The proposed method showed linearity over the concentration range of (0.5-25 µg/mL) and (0.1-25 µg/mL) for FLU and AZL, respectively. Besides that, the method was adopted in a short chromatographic run with satisfactory resolution factors of (2.39, 3.78 and 6.74 between PEA/FLU, FLU/AZL and AZL/BNZ), respectively. The performed method was efficiently applied to pharmaceutical nasal spray with (mean recoveries ± SD) (99.80 ± 0.97) and (100.26 ± 0.96) for FLU and AZL, respectively. Conclusion: The suggested method was based on simultaneous determination of FLU and AZL in the presence of PEA and BNZ in pure form, laboratory synthetic mixture and its combined pharmaceutical dosage form using green MELC technique with UV detection. The proposed method appeared to be superior to the reported ones of being more sensitive and specific, as well as the separation was achieved with good performance in a relatively short analysis time (less than 7.5 min). Highly acceptable values of LOD and % RSD make this method superior to be used in quality control laboratories with of HPLC technique.

scholarly journals Application of an LC–MS/MS Method for the Simultaneous Quantification of Homovanillic Acid and Vanillylmandelic Acid for the Diagnosis and Follow-Up of Neuroblastoma in 357 Patients

Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3470
Author(s):  
Narae Hwang ◽  
Eunbin Chong ◽  
Hyeonju Oh ◽  
Hee Won Cho ◽  
Ji Won Lee ◽  
...  
Keyword(s):  
Lower Limit ◽  
Large Scale ◽  
Homovanillic Acid ◽  
Limit Of Detection ◽  
Method Comparison ◽  
Vanillylmandelic Acid ◽  
Limit Of Quantification ◽  
Spot Urine ◽  
Minimal Sample ◽  
Clinical Biomarkers

Homovanillic acid (HVA) and vanillylmandelic acid (VMA) are end-stage metabolites of catecholamine and are clinical biomarkers for the diagnosis of neuroblastoma. For the first time in Korea, we implemented and validated a liquid chromatography tandem mass spectrometry (LC–MS/MS) assay to measure urinary concentrations of HVA and VMA according to Clinical and Laboratory Standards Institute guidelines. Our LC–MS/MS assay with minimal sample preparation was validated for linearity, lower limit of detection (LOD), lower limit of quantification (LLOQ), precision, accuracy, extraction recovery, carryover, matrix effect, and method comparison. A total of 1209 measurements was performed to measure HVA and VMA in spot urine between October 2019 and September 2020. The relationship between the two urinary markers, HVA and VMA, was analyzed and exhibited high agreement (89.1% agreement, kappa’s k = 0.6) and a strong correlation (Pearson’s r = 0.73). To our knowledge, this is the first study to utilize LC–MS/MS for simultaneous quantitation of spot urinary HVA and VMA and analyze the clinical application of both markers on a large scale for neuroblastoma patients.

scholarly journals On Robust State Estimation of Gene Networks

2010 ◽  
Vol 2 ◽  
pp. 117959721000200 ◽  
Author(s):  
Chia-Hua Chuang ◽  
Chun-Liang Lin
Keyword(s):  
Parameter Estimation ◽  
Kalman Filter ◽  
Quantitative Analysis ◽  
State Estimation ◽  
Gene Networks ◽  
Gene Network ◽  
Biological Systems ◽  
Uncertain Process ◽  
Network Systems ◽  
Internal States

Gene networks in biological systems are not only nonlinear but also stochastic due to noise corruption. How to accurately estimate the internal states of the noisy gene networks is an attractive issue to researchers. However, the internal states of biological systems are mostly inaccessible by direct measurement. This paper intends to develop a robust extended Kalman filter for state and parameter estimation of a class of gene network systems with uncertain process noises. Quantitative analysis of the estimation performance is conducted and some representative examples are provided for demonstration.

Rapid Determination of Sufentanil in Human Plasma by UHPLC–QqQ-MS-MS

2020 ◽  
Author(s):  
Marcin Zawadzki ◽  
Grzegorz Kowalski ◽  
Agnieszka Chłopaś-Konowałek ◽  
Marta Siczek ◽  
Małgorzata Sobieszczańska ◽  
...  
Keyword(s):  
Human Plasma ◽  
Lower Limit ◽  
Rapid Determination ◽  
Ultra Performance Liquid Chromatography ◽  
Sample Volume ◽  
Small Sample ◽  
Plasma Samples ◽  
Limit Of Quantification ◽  
Detection And Identification

Abstract This paper presents a rapid, sensitive and precise method developed and validated for the quantification of sufentanil in biological samples using ultra-performance liquid chromatography coupled with QqQ-MS-MS. Plasma samples were extracted with simple and fast liquid-liquid extraction (ethyl acetate, pH 9). Calibration curve showed linearity in the concentration range of 0.005–30 µg/L. The lower limit of quantification was 0.010 µg/L. The most important method features are low lower limit of quantification value, simple plasma extraction and small sample volume. This method is suitable not only for evaluation of the pharmacokinetics, toxicology, bioavailability and clinical pharmacology of sufentanil but also for the detection and identification of this compound in human plasma samples for forensic purposes.

scholarly journals Development of a Rapid Resolution Liquid Chromatographic Method for Simultaneous Analysis of Four Alkaloids in Rhizoma coptidis Under Different Cultivation Conditions

2009 ◽  
Vol 92 (2) ◽  
pp. 663-671 ◽  
Author(s):  
Yan-Ling Qiao ◽  
Yu-Xin Sheng ◽  
Li-Qun Wang ◽  
Jin-Lan Zhang
Keyword(s):  
Lower Limit ◽  
Limit Of Detection ◽  
Gradient Elution ◽  
Reversed Phase ◽  
Specific Method ◽  
Good Precision ◽  
Cultivation Conditions ◽  
Limit Of Quantification ◽  
Rhizoma Coptidis ◽  
Rapid Resolution

Abstract A sensitive and specific method using rapid resolution liquid chromatography coupled with UV-Vis detection was developed for fingerprint analysis of Rhizoma coptidis and simultaneous determination of 4 alkaloids: jatrorrhizine, coptisine, palmatine, and berberine. Samples of R. coptidis grown under different cultivation conditions and from different habitats were analyzed. The analysis was performed using a reversed-phase octylsilyl (C8) column and gradient elution. The mobile phase consisted of acetonitrile and 20 mmol/L KH2PO4. Each analysis was completed within 3.5 min. The method showed good linearity within test ranges of 4.7547.50 g/mL for jatrorrhizine, 20.60164.80 g/mL for coptisine, 18.07180.73 g/mL for palmatine, and 89.70717.57 g/mL for berberine. The method showed good precision, repeatability, and stability for quantification of the 4 alkaloids. The lower limit of detection was 0.19 ng for jatrorrhizine, 0.21 ng for coptisine, 0.15 ng for palmatine, and 0.14 ng for berberine. The lower limit of quantification was 0.57 ng for jatrorrhizine, 0.82 ng for coptisine, 0.55 ng for palmatine, and 0.27 ng for berberine. The overall recovery ranged from 96.30 to 104.10 for the 4 alkaloids. The method is accurate, rapid, and convenient, and it is suitable for routine quality control of R. coptidis.

scholarly journals Qualitative and Quantitative Analysis of the Major Constituents in Chinese Medical Preparation Lianhua-Qingwen Capsule by UPLC-DAD-QTOF-MS

2015 ◽  
Vol 2015 ◽  
pp. 1-19 ◽  
Author(s):  
Weina Jia ◽  
Chunhua Wang ◽  
Yuefei Wang ◽  
Guixiang Pan ◽  
Miaomiao Jiang ◽  
...  
Keyword(s):  
Quantitative Analysis ◽  
Limit Of Detection ◽  
Mass Measurement ◽  
Array Detector ◽  
Qualitative And Quantitative Analysis ◽  
Limit Of Quantification ◽  
Qualitative And Quantitative ◽  
Medical Preparation ◽  
Flight Mass Spectrometry ◽  
Viral Influenza

Lianhua-Qingwen capsule (LQC) is a commonly used Chinese medical preparation to treat viral influenza and especially played a very important role in the fight against severe acute respiratory syndrome (SARS) in 2002-2003 in China. In this paper, a rapid ultraperformance liquid chromatography coupled with diode-array detector and quadrupole time-of-flight mass spectrometry (UPLC-DAD-QTOF-MS) method was established for qualitative and quantitative analysis of the major constituents of LQC. A total of 61 compounds including flavonoids, phenylpropanoids, anthraquinones, triterpenoids, iridoids, and other types of compounds were unambiguously or tentatively identified by comparing the retention times and accurate mass measurement with reference compounds or literature data. Among them, twelve representative compounds were further quantified as chemical markers in quantitative analysis, including salidroside, chlorogenic acid, forsythoside E, cryptochlorogenic acid, amygdalin, sweroside, hyperin, rutin, forsythoside A, phillyrin, rhein, and glycyrrhizic acid. The UPLC-DAD method was evaluated with linearity, limit of detection (LOD), limit of quantification (LOQ), precision, stability, repeatability, and recovery tests. The results showed that the developed quantitative method was linear, sensitive, and precise for the quality control of LQC.

scholarly journals Simultaneous Determination of Aspirin and Rosuvastatin Calcium in Capsules by Using RP-HPLC Coupled with Photo Diode Array Detection

2014 ◽  
Vol 33 ◽  
pp. 218-230
Author(s):  
Ankita Panchal ◽  
Gaurav Sanghvi ◽  
Ashish Vachhani ◽  
Navin Sheth ◽  
Devendra Vaishnav
Keyword(s):  
Quality Control ◽  
Simultaneous Determination ◽  
Lower Limit ◽  
Limit Of Detection ◽  
Pharmaceutical Formulations ◽  
Coefficient Of Determination ◽  
Limit Of Quantification ◽  
Relative Standard ◽  
Rosuvastatin Calcium

A simple, sensitive, specific, and cost effective method for simultaneous determination of Aspirin and Rosuvastatin calcium was developed and validated in single dosage formulation. The sample solution of ASP and RSTC was prepared using methanol as a solvent. Separation of ASP and RSTC was achieved with a mobile phase consisting of 20 mM KH2PO4 : Methanol (30:70 v/v) at a flow rate of 1.0 ml/min. Separations were performed on Merck hibar 250-4.6 RP18 (5 µm) column (150 mm X 3.0 mm), using a Shimadzu Prominence HPLC system equipped with a Shimadzu SPD-20A detector, Rhenodyne 7725i injector with 20 μL loop, LC-20 AD pump, CBM-20 Alite controller and LC Solution software. Retention times of ASP and RSTC were 3.747 and 5.969 minutes respectively. Absolute recovery of ASP and RSTC was 100.3 and 100.03 % respectively. The lower limit of quantification (LLOQ) of ASP and RSTC was 0.3097 and 0.1063 ppm and lower limit of detection (LLOD) of ASP and RSTC was 0.01535 and 0.01358 ppm respectively. Linearity was established for the range of concentrations 15.00-90.0 μg/ml and 2.0-12.0 μg/ml for ASP and RSTC respectively with the coefficient of determination (R2) of 0.994 and 0.999 for both the compounds. The inter- and intra-day precision in the measurement of ASP quality control (QC) sample 75 μg/ml, were in the range 0.1-0.2 % relative standard deviation (R.S.D.) and 0.2-0.3 % R.S.D., respectively. The inter- and intra-day precision in the measurement of RST quality control (QC) sample 10 μg/ml, were in the range 0.1-0.2 % R.S.D., and 0.0-0.3 % R.S.D., respectively. The developed method would be applicable for routine quality control of ASP And RSTC in bulk as well as in pharmaceutical formulations

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