Limits of Detection and Quantification in Comprehensive Multidimensional Separations. 1. A Theoretical Look

2012 ◽  
Vol 84 (15) ◽  
pp. 6646-6653 ◽  
Author(s):  
A. Paulina de la Mata ◽  
James J. Harynuk
Keyword(s):  
Limits Of Detection ◽  
Multidimensional Separations ◽  
Detection And Quantification

scholarly journals Quantitative Analysis of Bioactive Carbazole Alkaloids in Murraya koenigii

2015 ◽  
Vol 10 (2) ◽  
pp. 1934578X1501000
Author(s):  
Trapti Joshi ◽  
Rohit Mahar ◽  
Sumit K. Singh ◽  
Piush Srivastava ◽  
Sanjeev K. Shukla ◽  
...  
Keyword(s):  
Anticancer Agents ◽  
Uttar Pradesh ◽  
Central India ◽  
Ultra Performance Liquid Chromatography ◽  
Natural Abundance ◽  
Photodiode Array Detection ◽  
Limits Of Detection ◽  
Specific Distribution ◽  
Carbazole Alkaloids ◽  
Detection And Quantification

Carbazole alkaloids induce apoptosis in HL-60 cells through activation of the caspase-9/caspase-3 pathway and they are targeted as potential anticancer agents. Thus, the naturally occurring carbazole alkaloids become important as precursors for lead optimization in drug development. A method based on ultra performance liquid chromatography coupled with photodiode-array detection was developed using reverse phase isocratic elution with 85:15 acetonitrile and ammonium acetate buffer (5 mM). Seven samples of Murrya koenigii (L.) Spreng. from north-central India ( Uttar Pradesh) were analyzed. All three targeted analytes, koenimbidine (mk1), koenimbine (mk2) and mahanimbine (mk3), were well separated within 4.0 min with linearity of the calibration curves (r2 > 0.999). The limits of detection and quantification of mk1, mk2 and mk3 were 0.7, 0.4, 0.04 μg/mL and 2.14, 1.21, 0.12 μg/mL, respectively. The natural abundance of mk1, mk2 and mk3 was 0.06 - 0.20, 0.04 - 0.69 and 0.13 - 0.42%, w/w, respectively, in the dried powdered leaves, whereas, the tissue specific distribution of carbazole alkaloids was observed in the order of predominance, mk1 leaf>root>fruit>stem, mk2 fruit>leaf >stem>root, and mk3 fruit>leaf>root>stem. The developed method was validated for limits of detection and quantification, repeatability, accuracy, precision and stability. This is the first report on the natural abundance of the major carbazole alkaloids in M. koenigii and the method developed can be used in HPLC/UPLC systems.

scholarly journals Validation and Optimization of Ultrasound-Assisted Dispersive LiquidLiquid Microextraction as a Preparation Method for Detection of Methadone in Saliva with Gas Chromatography-Mass Spectrometry Technique

2020 ◽  
Vol 10 (2) ◽  
pp. 329-333 ◽  
Author(s):  
Ahmad Shekari ◽  
Mehdi Forouzesh ◽  
Roohollah Valipour ◽  
Fardin Fallah ◽  
Pardis Shojaei
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Preparation Method ◽  
Gas Chromatography Mass Spectrometry ◽  
Phase Volume ◽  
Limits Of Detection ◽  
Chromatography Mass Spectrometry ◽  
Ultrasound Assisted ◽  
Detection And Quantification ◽  
Extraction Phase

Purpose: We investigated validation and optimization of ultrasound-assisted dispersive liquidliquid microextraction (UADLLME) as a preparation method for detection of methadone in saliva samples. Methods: We used blank and methadone-containing saliva samples and also standard methadone solution. Sodium hydroxide and chloroform were added to samples and they were held in ultrasonic bath. Then preparations were centrifuged and extracted analyte was analyzed by gas chromatography-mass spectrometry (GC-MS). Accuracy was measured by Intra and between-day mean relative errors (RE). Precision was assessed by coefficient of variation (CV). Recovery, specificity, linearity and limits of detection and quantification were also determined. Optimization was conducted for ultrasound duration, pH and extraction phase volume. Efficiency of dispersive liquid-liquid microextraction (DLLME) and UADLLME were compared. Results: Intra and between-day accuracies (2.3 -7.5%), recovery (89.4-115.5%) and precision (5.2-11.3%) were all acceptable. Calibration curve was linear in the concentration range of 150 ng/mL-10 µL/mL with R2 >0.9995 and equation of y=86.901x-5342.5. Limits of detection and quantification were 50 and 150 ng/mL, respectively. Specificity was measured by comparing retention times of saliva samples (containing methadone metabolites and other commonly used drugs) during UADLLME/GC-MS analysis and no interference was observed. Recovery of UADLLME was 1.4 of DLLME. Solvent and sample volumes required for UADLLME were 1/200 and 1/20 of DLLME. The greatest efficiency obtained at pH of 10, with ultrasound treatment duration of 5 minutes and extraction phase volume of 1000 µL. Conclusion: Study found that UADLLME/GC-MS is a valid and efficient method for detection of methadone in oral fluid.

scholarly journals DEVELOPMENT AND VALIDATION OF AN HIGH-PERFORMANCE LIQUID CHROMATOGRAPHY METHOD FOR THE DETERMINATION OF 17-Β ESTRADIOL IN POLYMERIC NANOPARTICLES

2021 ◽  
pp. 112-116
Author(s):  
ADRIANA YURIKO KOGA ◽  
BRUNA CARLETTO ◽  
LEANDRO CAVALCANTE LIPINSKI ◽  
TRAUDI KLEIN ◽  
PAULO VITOR FARAGO
Keyword(s):  
Liquid Chromatography ◽  
High Performance ◽  
Polymeric Nanoparticles ◽  
Chromatography Method ◽  
Limits Of Detection ◽  
Ph Variation ◽  
Liquid Chromatography Method ◽  
The Stability ◽  
Development And Validation ◽  
Detection And Quantification

Objective: A simple high-performace liquid chromatography method was developed and validated to determine 17-β estradiol in poly (ε-caprolactone) nanocapsules. Methods: The chromatographic conditions were as follows: C18 GL column with a mobile phase of acetonitrile:water (92:8 v/v) at flow rate of 1.5 mL/min with detection at 280 nm. The evaluated parameters were specificity, linearity, limits of detection and quantification, precision, accuracy, and robustness. Results: The method was specific and linear (r=0.9982). The limits of detection and quantification were 5.78 μg.mL-1 and 17.54 μg.mL-1, respectively. Suitable accurancy and robustness were obtained. The stability assay showed that pH variation occured after 120 days of storage, and no changes were observed regarding the size and polydispersion parameters. The applicability of the method was evaluated by determining the encapsulation efficiency of the E2 nanocapsules after 120 days of storage. The results showed values >99%. Conclusion: The results demonstrated the applicability of the developed and validated analytical method.

High-Performance Liquid Chromatography Quantitative Determination of Oxyresveratrol and Morin Contained in Maclura cochinchinensis Extract and Gel Formulation

2021 ◽  
Vol 901 ◽  
pp. 79-85
Author(s):  
Arpa Petchsomrit ◽  
Boonyadist Vongsak
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
High Performance ◽  
Anticancer Activities ◽  
Limits Of Detection ◽  
Percent Recovery ◽  
Relative Standard ◽  
Traditional Drug ◽  
Detection And Quantification

Maclura cochinchinensis (Lour.) Corner., of the Moraceae family, is a medical shrub commonly found in Thailand, and for which a wide variety of pharmacological activities have been reported, including antiviral, anti-inflammatory, antioxidant, and anticancer activities. The main bioactive compounds, oxyresveratrol and morin, are known to be found in M. cochinchinensis heartwood. In this study, we quantitatively analyzed the levels of these two active substances in M. cochinchinensis extracted with various solvents, including in various cosmetic formulations and herbs sourced from various parts of Thailand. High-performance liquid chromatography (HPLC) was performed on a C18 column with an isocratic elution using 1.5% formic acid and acetonitrile at a flow rate of 1 ml/min, and detected at 352 nm. This method was validated for accuracy, precision, linearity, limits of detection, and quantification. The average percent recovery for oxyresveratrol and morin in the extracts was 100.01 ± 0.62% and 99.31 ± 2.56%, and in gel formulation was 99.65 ± 3.54% and 118.41 ± 4.70%, respectively. The relative standard deviation of intra- and inter-day precision was less than 2.0% and 2.8%, respectively. Limits of detection and quantification were 0.06 and 0.2 μg/ml, respectively. The amounts of oxyresveratrol and morin extracted from different solvents, such as acetone, 80% ethanol, 50% ethanol, methanol, and distilled water were in the range of 37.75–68.16 and 54.63–144.83 mg/g, respectively, while five samples of M. cochinchinensis heartwood collected from different regions of traditional drug stores contained in the range of 26.85–60.37 and 110.26–157.44 mg/g, respectively. Additionally, the percentage label amounts of oxyresveratrol and morin were analyzed in gel preparations, and found at 82.88% and 120.99%, respectively. This technique is convenient, simple, and reliable to effectively analyze the content of these active compounds in extracts and cosmetic products.

scholarly journals Antibiotic microbial assay using kinetic-reading microplate system

2011 ◽  
Vol 47 (3) ◽  
pp. 573-584 ◽  
Author(s):  
Felipe Rebello Lourenço ◽  
Terezinha de Jesus Andreoli Pinto
Keyword(s):  
Culture Media ◽  
Experimental Conditions ◽  
Limits Of Detection ◽  
Standard Curve ◽  
Accuracy And Precision ◽  
Physico Chemical ◽  
Test Microorganism ◽  
Microbial Assay ◽  
Turbidimetric Assay ◽  
Detection And Quantification

The aim of this study was to determine the optimal experimental conditions to develop a methodology for microbiological assay of apramycin employing microplate and kinetic reading mode, and to validate the developed method, through evaluation of parameters of selectivity, linearity, linear range, limits of detection and quantification, accuracy and precision. The turbidimetric assay principle is simple: the test solution is added to a suspension of test microorganism in culture media, the mixture is incubated under appropriate conditions and the microbial growth is measured by photometric reading. Microplate with kinetic reading mode employed in antibiotic assay is of considerable interest since it allows reduction of material and analysis time and enables a large number of samples to be analyzed simultaneously, with automated reading and calculating. Established conditions considered the standard-curve of apramycin at concentrations from 5.0 to 35.0 μg mL-1, and tryptic soy broth inoculated with 5% Escherichia coli (ATCC 8739) suspension. Satisfactory results were obtained with 2 hours of incubation. The developed method showed appropriate selectivity, linearity in the range from 5.0 to 35.0 μg mL-1, limits of detection and quantification of 0.1 and 0.4 μg mL-1, respectively, as well as satisfactory accuracy (recuperation = 98.5%) and precision (RSD = 6.0%). Microplate assay combined the characteristics of microbiological (evaluation of antibiotic activity against sensitive test microorganism) and physico-chemical (operationally straightforward and faster results) assays.

scholarly journals Increasing Liquid Chromatography–Tandem Mass Spectrometry Throughput by Mass Tagging: A Sample-Multiplexed High-Throughput Assay for 25-Hydroxyvitamin D2 and D3

2011 ◽  
Vol 57 (3) ◽  
pp. 431-440 ◽  
Author(s):  
Brian C Netzel ◽  
Kendall W Cradic ◽  
Eric T Bro ◽  
Adam B Girtman ◽  
Richard C Cyr ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
Tandem Mass Spectrometry ◽  
Tandem Mass ◽  
Limits Of Detection ◽  
Sample Throughput ◽  
Chromatography Tandem Mass Spectrometry ◽  
Deming Regression ◽  
Liquid Chromatography Tandem Mass ◽  
Detection And Quantification

BACKGROUND The limits of chromatographic speed and mechanical frontend capabilities have been reached for many high-volume liquid chromatography–tandem mass spectrometry (LC-MS/MS) tests, curtailing the maximal achievable sample throughput. To overcome these boundaries, we developed and validated a derivatization-based sample-multiplex LC-MS/MS assay for detection of 25-hydroxyvitamins D2 and D3 [25(OH)D2 and 25(OH)D3], which increased sample throughput 5-fold. METHODS After separate derivatization with 1 of 5 different triazoline-diones (TADs), 5 calibrators, controls, or patient specimens were combined and injected together into an LC-MS/MS. On the basis of mass differences between TADs, the MS/MS quantified analyte and stable isotope internal standards for 25(OH)D2 and 25(OH)D3 for each respective multiplexed sample within the injection. Limits of detection and quantification, spiked recovery, linearity, imprecision, and patient results were determined and compared against our standard LC-MS/MS assay. RESULTS TAD multiplexing increased throughput on an LC-quadruplexed LC-MS/MS system from 60 samples/h to 300 samples/h. Limits of detection and quantification were 4.9 nmol/L [2 μg/L, 25(OH)D2], 2.2 nmol/L [0.9 μg/L, 25(OH)D3], and 10 nmol/L [4 μg/L, 25(OH)D2], 5 nmol/L [2 μg/L, 25(OH)D3], respectively. The assay was linear to 250 nmol/L (100 μg/L). Interassay CVs across the reportable range were 3.7%–15.2%. Spiked recoveries were 94%–119%. The method comparison with the standard LC-MS/MS method showed slopes of 0.96 and 0.97 (Deming regression) for 25(OH)D2 (n = 1733) and 25(OH)D3 (n = 7614) (R2=0.96 and 0.97), respectively. CONCLUSIONS Multiplexing samples by differential mass tagging in LC-MS/MS measurement of 25(OH)D2 and 25(OH)D3 allows for reliable quantification, with throughput increased over standard methods by the multiplexing factor.

scholarly journals DEVELOPMENT AND VALIDATION OF A FAST AND SENSITIVE UHPLC-PDA METHOD FOR THE QUANTIFICATION OF URSOLIC ACID IN POLY(L-LACTIC ACID) NANOCAPSULES

2020 ◽  
pp. 161-165
Author(s):  
BRUNA CARLETTO ◽  
AMANDA MARTINEZ LYRA ◽  
ADRIANA YURIKO KOGA ◽  
ANDRESSA NOVATSKI ◽  
RUBIANA MARA MAINARDES ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Ursolic Acid ◽  
Flow Rate ◽  
Mobile Phase ◽  
High Performance ◽  
Limits Of Detection ◽  
Column Temperature ◽  
Relative Standard ◽  
Development And Validation ◽  
Detection And Quantification

Objective: The aim of the present study is to develop and validation of a ultra-high performance liquid chromatography (UHPLC) method to determine the ursolic acid content and its encapsulation efficiency (EE) in lipid-core nanocapsules prepared from poly (L-lactic acid). Methods: A simple UHPLC-PDA method was developed and validated for the quantitative determination of ursolic acid in poly(L-lactic acid) nanocapsules. The chromatographic conditions used were: RP-C18 column, isocratic mobile phase containing acetonitrile:water (92:8, v/v), flow rate of 0.8 ml/min, column temperature of 50°C, and detection at 203 nm. The following parameters were evaluated: Specificity, linearity, limits of detection and quantification, precision, accuracy, and robustness. Results: The method was specific to the ursolic acid and linear (r=0.9998) in the range of 10–100 μg/ml. The limits of detection and quantification were 1.35 and 4.10 μg/ml, respectively. The precision was demonstrated by a relative standard deviation less than 2%. Adequate accuracy (98.35%±0.82) was obtained. Changes in flow rate, mobile phase, and column temperature did not significantly alter the peak area and the retention time of the ursolic acid. The mean EE was 99.89%. Conclusion: The method proved to be fast, sensitive, and simple for quantifying ursolic acid in nanocapsules and was successfully used for determining the EE.

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