Determination of Free Solanesol Levels in Cigarette Filters by Liquid Chromatography–Mass Spectrometry

2021 ◽  
Author(s):  
Roberto Bravo Cardenas ◽  
Phuong Ngac ◽  
Clifford Watson ◽  
Liza Valentin-Blasini
Keyword(s):  
Liquid Chromatography ◽  
Sample Preparation ◽  
Tobacco Smoke ◽  
Limit Of Detection ◽  
Internal Standard ◽  
Filter Material ◽  
Previous Method ◽  
Tobacco Smoke Exposure ◽  
Triple Quadrupole Mass Spectrometer ◽  
Cigarette Butts

Abstract Solanesol, a naturally occurring constituent of tobacco, has been utilized as a good marker for environmental tobacco smoke particulate and as a noninvasive predictor of mainstream cigarette smoke tar and nicotine intake under naturalistic smoking conditions. A fast and accurate method for measuring free solanesol to assess tobacco smoke exposure is highly desirable. We have developed and validated a new environmentally friendly, high-throughput method for measuring solanesol content in discarded cigarette filter butts. The solanesol deposited in the used filters can be correlated with mainstream smoke deliveries of nicotine and total particle matter to estimate constituent delivery to smokers. A portion of filter material is removed from cigarette butts after machine smoking, spiked with internal standard solution, extracted and quantitatively analyzed using reverse-phase liquid chromatography coupled to a triple-quadrupole mass spectrometer. The new method incorporates a 48-well plate format for automated sample preparation that reduces sample preparation time and solvent use and increases sample throughput 10-fold compared to our previous method. Accuracy and precision were evaluated by spiking known amounts of solanesol on both clean and smoked cigarette butts. Recoveries exceeded 93% at both low and high spiking levels. Linear solanesol calibration curves ranged from 1.9 to 367 µg/butt with a 0.05 µg/butt limit of detection.

scholarly journals Development and validation of a liquid chromatography-tandem mass spectrometric method for the determination of lenalidomide in human plasma and its application on bioequivalence studies

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
R. Gopinath ◽  
S. T. Narenderan ◽  
M. Kumar ◽  
B. Babu
Keyword(s):  
Liquid Chromatography ◽  
Human Plasma ◽  
Internal Standard ◽  
Spectrometric Method ◽  
Tandem Mass ◽  
Mass Spectrometric Method ◽  
Mass Detection ◽  
Triple Quadrupole Mass Spectrometer ◽  
Liquid Chromatography Tandem Mass ◽  
Tandem Mass Spectrometric

AbstractA simple, sensitive, and specific liquid chromatography-tandem mass spectrophotometry (LC-MS/MS) method was developed and validated for the quantification of lenalidomide in human plasma. The separation was carried out on a symmetry, C18, 5-μm (50 × 4.6 mm) column as stationary phase and with an isocratic mobile phase of 0.1% formic acid in water-methanol in the ratio of (15:85, v/v) at a flow rate of 0.5 mL/min. Protonated ions formed by electrospray ionization in the positive mode were used to detect analyte and fluconazole (internal standard). The mass detection was made by monitoring the fragmentation of m/z 260.1/148.8 for lenalidomide and m/z 307.1/238.0 for internal standard on a triple quadrupole mass spectrometer. The developed method was validated over the concentration range of 10–1000 ng/mL for lenalidomide in human plasma with a correlation coefficient (r2) was 0.9930. The accuracy and precision values obtained from six different sets of quality control samples analyzed on separate occasions ranged from 99.41 to 106.97% and 2.88 to 4.22%, respectively. Mean extraction recoveries were 98.06% and 88.78% for the analyte and IS, respectively. The developed method was successfully applied for analyzing lenalidomide in human plasma samples.

scholarly journals Quantification of plasma remdesivir and its metabolite GS-441524 using liquid chromatography coupled to tandem mass spectrometry. Application to a Covid-19 treated patient

2020 ◽  
Vol 58 (9) ◽  
pp. 1461-1468 ◽  
Author(s):  
Jean-Claude Alvarez ◽  
Pierre Moine ◽  
Isabelle Etting ◽  
Djillali Annane ◽  
Islam Amine Larabi
Keyword(s):  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
Half Life ◽  
Limit Of Detection ◽  
Treated Patient ◽  
Internal Standard ◽  
Therapeutic Drug ◽  
Active Metabolites ◽  
Limit Of Quantification ◽  
Positive Mode

AbstractObjectivesA method based on liquid chromatography coupled to triple quadrupole mass spectrometry detection using 50 µL of plasma was developed and fully validated for quantification of remdesivir and its active metabolites GS-441524.MethodsA simple protein precipitation was carried out using 75 µL of methanol containing the internal standard (IS) remdesivir-13C6 and 5 µL ZnSO4 1 M. After separation on Kinetex® 2.6 µm Polar C18 100A LC column (100 × 2.1 mm i.d.), both compounds were detected by a mass spectrometer with electrospray ionization in positive mode. The ion transitions used were m/z 603.3 → m/z 200.0 and m/z 229.0 for remdesivir, m/z 292.2 → m/z 173.1 and m/z 147.1 for GS-441524 and m/z 609.3 → m/z 206.0 for remdesivir-13C6.ResultsCalibration curves were linear in the 1–5000 μg/L range for remdesivir and 5–2500 for GS-441524, with limit of detection set at 0.5 and 2 μg/L and limit of quantification at 1 and 5 μg/L, respectively. Precisions evaluated at 2.5, 400 and 4000 μg/L for remdesivir and 12.5, 125, 2000 μg/L for GS-441524 were lower than 14.7% and accuracy was in the [89.6–110.2%] range. A slight matrix effect was observed, compensated by IS. Higher stability of remdesivir and metabolite was observed on NaF-plasma. After 200 mg IV single administration, remdesivir concentration decrease rapidly with a half-life less than 1 h while GS-441524 appeared rapidly and decreased slowly until H24 with a half-life around 12 h.ConclusionsThis method would be useful for therapeutic drug monitoring of these compounds in Covid-19 pandemic.

scholarly journals Sensitive Analysis of Idarubicin in Human Urine and Plasma by Liquid Chromatography with Fluorescence Detection: An Application in Drug Monitoring

Molecules ◽  
2020 ◽  
Vol 25 (24) ◽  
pp. 5799
Author(s):  
Olga Maliszewska ◽  
Natalia Treder ◽  
IIona Olędzka ◽  
Piotr Kowalski ◽  
Natalia Miękus ◽  
...  
Keyword(s):  
Liquid Chromatography ◽  
Human Plasma ◽  
Fluorescence Detection ◽  
Limit Of Detection ◽  
Solid Phase ◽  
Biological Fluids ◽  
Internal Standard ◽  
Urine Samples ◽  
Human Plasma And Urine ◽  
Plasma And Urine Samples

A new approach for the sensitive, robust and rapid determination of idarubicin (IDA) in human plasma and urine samples based on liquid chromatography with fluorescence detection (LC-FL) was developed. Satisfactory chromatographic separation of the analyte after solid-phase extraction (SPE) was performed on a Discovery HS C18 analytical column using a mixture of acetonitrile and 0.1% formic acid in water as the mobile phase in isocratic mode. IDA and daunorubicin hydrochloride used as an internal standard (I.S.) were monitored at the excitation and emission wavelengths of 487 and 547 nm, respectively. The method was validated according to the FDA and ICH guidelines. The linearity was confirmed in the range of 0.1–50 ng/mL and 0.25–200 ng/mL, while the limit of detection (LOD) was 0.05 and 0.125 ng/mL in plasma and urine samples, respectively. The developed LC-FL method was successfully applied for drug determinations in human plasma and urine after oral administration of IDA at a dose of 10 mg to a patient with highly advanced alveolar rhabdomyosarcoma (RMA). Moreover, the potential exposure to IDA present in both fluids for healthcare workers and the caregivers of patients has been evaluated. The present LC-FL method can be a useful tool in pharmacokinetic and clinical investigations, in the monitoring of chemotherapy containing IDA, as well as for sensitive and reliable IDA quantitation in biological fluids.

scholarly journals Discrepancy between Self-Reported and Urine Cotinine-Verified Environmental Tobacco Smoke Exposure among Rural Pregnant Women in China

2018 ◽  
Vol 15 (7) ◽  
pp. 1499 ◽  
Author(s):  
Xia Xiao ◽  
Yan Li ◽  
Xiaoxiao Song ◽  
Qinghua Xu ◽  
Siwei Yang ◽  
...  
Keyword(s):  
Pregnant Women ◽  
Environmental Tobacco Smoke ◽  
Tobacco Smoke ◽  
Rural Women ◽  
Rural Areas ◽  
Limit Of Detection ◽  
Tobacco Smoke Exposure ◽  
Tobacco Exposure ◽  
Third Trimester ◽  
The Family

Prenatal exposure to environmental tobacco smoke (ETS) is the most modifiable risk factor associated with adverse child-health outcomes. However, few longitudinal studies are implemented to compare the rates of discrepancy between self-reported (SR) and urinary cotinine (UC)-verified ETS exposure during the three trimesters of pregnancy, especially in rural areas. The objectives of this study were to assess the discrepancy between SR and UC-verified ETS exposure among rural women employing three measures throughout pregnancy, and to explore predictors related to these differences. This study used a prospective prenatal cohort consisting of 420 pregnant women whose ETS exposure was entirely evaluated by both SR and UC verification across three trimesters of pregnancy. Environmental tobacco exposure was assessed via SR verification, and was validated using the limit of detection for UC. The discrepancy rates were determined for each trimester. Multivariate logistic regression was used to assess the predictors associated with these differences. The discrepancy rates between SR and UC verification were 25.2%, 17.1%, and 20.5% (first, second, and third trimester, respectively). The highest inconsistency occurred in the first trimester. After adjusting for confounding factors, the following variables were found to have statistically significant associations with the discrepancy rate between SR and UC-verified ETS exposure: the number of smokers in the family and household income for all three trimesters, township site for the second and third trimester, and gravidity for the last trimester. The SR rate of ETS exposure among rural pregnant women is underreported, while the UC-verified rate is higher. More smokers in the family and gravidity may increase the risk of ETS exposure for pregnant women. Biochemical validation is warranted throughout pregnancy for the adoption of home-smoking bans and the promotion of community-based smoke-free programs.

Measurement of gliclazide in plasma by radial compression reversed-phase liquid chromatography.

1984 ◽  
Vol 30 (11) ◽  
pp. 1789-1791 ◽  
Author(s):  
B G Charles ◽  
P J Ravenscroft
Keyword(s):  
Liquid Chromatography ◽  
High Performance ◽  
Limit Of Detection ◽  
Internal Standard ◽  
Reversed Phase ◽  
Radial Compression ◽  
Reversed Phase Liquid Chromatography ◽  
Minimal Sample ◽  
Precise Analysis ◽  
Phase Liquid

Abstract We describe a rapid, specific, and precise analysis for gliclazide in plasma by radial compression, reversed-phase, "high-performance" liquid chromatography. Gliclazide and the internal standard, 3-chlorogliclazide, are eluted after 4.4 and 6.8 min, respectively. Only 100 microL of plasma and minimal sample workup are required. The limit of detection for gliclazide in plasma is 0.5 mg/L (1.55 mumol/L) at 229 nm. Precision (CV) of the assay for 10 and 1 mg of gliclazide per litre is 2.1% and 6.4%, respectively.

scholarly journals Determination of Cyclamate in Foods by Ultraperformance Liquid Chromatography/Tandem Mass Spectrometry

2008 ◽  
Vol 91 (5) ◽  
pp. 1095-1102 ◽  
Author(s):  
Robert Sheridan ◽  
Thomas King
Keyword(s):  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
Sample Preparation ◽  
Tandem Mass Spectrometry ◽  
Limit Of Detection ◽  
Tandem Mass ◽  
Chromatography Tandem Mass Spectrometry ◽  
Limit Of Quantitation ◽  
Liquid Chromatography Tandem Mass

Abstract A highly sensitive and selective method that requires minimal sample preparation was developed for the confirmation and quantitation of cyclamate in a variety of foods by high-performance liquid chromatography/tandem mass spectrometry (HPLC/MS/MS). Sample preparation consisted of homogenization followed by extraction and dilution of cyclamate with water. HPLC separation was achieved using a bridged ethyl hybrid C18 high-pressure column with a mobile phase consisting of 0.15 acetic acid and methanol. Under electrospray ionization negative conditions, quantitation was achieved by monitoring the fragment m/z 79.7 while also collecting parent ion m/z 177.9. Two food matrixes, diet soda and jelly, were subjected to a validation procedure in order to evaluate the applicability of the method. The cyclamate limit of detection for both matrixes was determined to be 0.050 g/g with a limit of quantitation of 0.150 g/g. The correlation coefficient of the calibration curves was >0.9998 from 0.0005 to 0.100 g/mL. The method has been used for the determination of cyclamate in several foods and the results are presented.

Excellence in Laboratory Practice with the Validation of Opiate Confirmation using Liquid Chromatography/Mass Spectrometry

2021 ◽  
Vol 156 (Supplement_1) ◽  
pp. S34-S34
Author(s):  
S Dalal ◽  
D Jhala
Keyword(s):  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
Sample Preparation ◽  
Drugs Of Abuse ◽  
Limit Of Detection ◽  
Gas Chromatography Mass Spectrometry ◽  
Liquid Chromatography Mass Spectrometry ◽  
Laboratory Practice ◽  
Ion Suppression ◽  
Chromatography Mass Spectrometry

Abstract Introduction/Objective Veterans are more susceptible to opioid addiction as they are more likely to suffer from chronic pain which leads to increased need of confirmed identification of opiates in toxicology laboratories. Gas chromatography-mass spectrometry (GC-MS) had been a long-accepted method for the quantitative analysis of opiates in urine, but requires tedious, time-consuming, and complex sample preparation steps. On the other hand, liquid chromatography-mass spectrometry (LC/MS) has comparatively simpler sample preparation steps, can handle three times the number of specimens, much faster turnaround times and produces equally valid results. However, the validation experience of this simpler detection method has not been well published, particularly in a Veterans Healthcare Clinical Laboratory setting. Methods/Case Report The quality assurance goal of the validation is to demonstrate that the Agilent 6410 Triple Quadrupole LC/MS (Wilmington DE) is able to identify the same opiate drug analytes performed by the GC-MS. Method to method correlation, within run precision, day to day precision, carryover study, matrix (ion) suppression study, and a limit of detection study were performed as part of this validation. Results (if a Case Study enter NA) For the total of 156 specimens run for the method comparison, there was 94.9% agreement, or 148/156 samples were concordant. The 8 discrepancies had drugs that were present below the cutoff limit of the LC/MS. Within run precision with 20 replicates of negative, positive, and at the cutoff were run with all results as expected. The day to day precision of a positive and negative sample run over 10 days also yielded results as expected. The carryover study demonstrated minimal carryover. The matrix (ion) suppression study showed ion suppression at 16.8%, which is below the amount needed to affect analyte concentrations. The LC/MS was highly sensitive with a limit of detection of >97% at 25 ng/mL. Thus, the result of comparison showed good concordance. Conclusion LC/MS is a simpler, more efficient method of opiate testing that is comparable to GC-MS for the detection of opiate drugs of abuse in urine. This is an example of excellence in laboratory practice by extending the best quality laboratory care with proper validation of instrument methods conducive to laboratory workflow.

scholarly journals METHOD DEVELOPMENT AND VALIDATION FOR ANALYSIS OF DEOXYARBUTININ ANHYDROUS EMULSION SYSTEM USING HIGH-PERFORMANCE LIQUID CHROMATOGRAPHY

2019 ◽  
pp. 172-175 ◽  
Author(s):  
MUCHTARIDI MUCHTARIDI ◽  
IDA MUSFIROH ◽  
AHMAD FAUZI
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Analytical Method ◽  
High Performance ◽  
Method Development ◽  
Limit Of Detection ◽  
Internal Standard ◽  
Emulsion System ◽  
Relative Standard ◽  
Limit Of Quantitation

Objective: The aim of this study is to develop a simple, precise and accurate analytical method of deoxyarbutin in anhydrous emulsion system preparation. Methods: The analysis was conducted using high-performance liquid chromatography (HPLC). Chromatographic analysis was carried out using a reversed phase-C18 column. The mobile consists of two phases methanol and water (60: 40 v/v) at a flow rate of 1.0 ml/min. The determinations were performed using UV detector set at 225 nm. All validation procedures were added with hydroquinone as an internal standard. Results: The method showed coefficient correlation is 0.9978, relative standard deviation (RSD) smaller than 2%, Limit of Detection (LOD) and Limit of Quantitation (LOQ) are 0.599 µg/ml and 1.817 µg/ml respectively. The total amount deoxyarbutin in anhydrous emulsion preparation is 1.964+0.02 % with 98% recovery percentage. Conclusion: The developed HPLC analytical method meets the validation criteria made by International Conference on Harmonisation (ICH).

scholarly journals Comparison of LC-MS Assay and HPLC Assay of Busulfan in Clinical Pharmacokinetics Studies

2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
Hongxia Lin ◽  
Susan Goodin ◽  
Roger K. Strair ◽  
Robert S. DiPaola ◽  
Murugesan K. Gounder
Keyword(s):  
Sample Preparation ◽  
Pharmacokinetic Model ◽  
Limit Of Detection ◽  
Internal Standard ◽  
Pharmacokinetic Parameters ◽  
Precolumn Derivatization ◽  
Hplc Assay ◽  
Clinical Pharmacokinetics ◽  
Liquid Liquid Extraction ◽  
Assay Precision

Busulfan is used in preparative regimens for bone marrow transplantation and timely busulfan plasma concentration reporting is critical for subsequent dose adjustment. We compared two sensitive methods for pharmacokinetics studies including LC-MS assay and HPLC precolumn derivatization assay. Chromatographic separation was performed on a Gemini C18 column. Liquid-liquid extraction with ethyl acetate was used for plasma sample preparation. Busulfan and internal standard ([2H8]-busulfan) were detected as ammonium adducts at m/z 264.2 and 272.2 for LC-MS assay. For HPLC assay, the extraction from plasma was derivatized with 2-naphathalenethiol using synthesized internal standard (1,6-(methanesulfonyloxy)octane). The Ex and Em wavelength was 255 nm and 370 nm. The limit of detection was 15.6 ng/mL and 7.8 ng/mL for HPLC and LC-MS assay and good linearity ranging from 31.25–1000 ng/mL for HPLC and 15.6-1000 ng/mL for LC-MS assay. The intra and interday assay precision were less than 9.2% and 12.0% for LC-MS and HPLC assay. The pharmacokinetic parameters were estimated using noncompartmental pharmacokinetic model with WinNonlin. Busulfan AUClast showed an average difference of 0.7% between the two methods. The LC-MS method is accurate, reproducible, and requires less specimen, sample preparation and analysis time over the HPLC assay, making busulfan monitoring faster and easier in clinical practice.

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