scholarly journals Simultaneous Determination of Cholecalciferol (Vitamin D3) and Ergocalciferol (Vitamin D2) in Foods by Selected Reaction Monitoring

2009 ◽  
Vol 92 (2) ◽  
pp. 511-517 ◽  
Author(s):  
Gianluca Dimartino
Keyword(s):  
Vitamin D3 ◽  
Ion Trap ◽  
Atmospheric Pressure Chemical Ionization ◽  
Internal Standard ◽  
Selected Reaction Monitoring ◽  
Vitamin D2 ◽  
Reaction Monitoring ◽  
Ionization Source ◽  
Relative Standard ◽  
Pressure Chemical Ionization

Abstract Cholecalciferol (vitamin D3) and ergocalciferol (vitamin D2) were determined simultaneously by selected reaction monitoring (SRM) mass spectrometry for different food matrixes. A small amount of starting sample was saponified and extracted before injection into a linear ion trap mass spectrometer equipped with an atmospheric pressure chemical ionization source. Dihydrotachysterol, which is absent from food and has a structure similar to that of vitamins D3 and D2, was used as an internal standard. Calibration curves for the 2 vitamins showed linearity with R2 values of 0.9999 and 0.9989 for vitamins D3 and D2, respectively. Limits of detection for vitamins D3 and D2 were 0.5 ng/g (1.3 pmol/g) and 1.75 ng/g (4.4 pmol/g) and limits of quantitation were 1.25 ng/g (3.24 pmol/g), and 3.75 ng/g (9.45 pmol/g), respectively. Accuracy and precision of the method were tested with the infant formula reference standard of the National Institute of Standards and Technology, which showed a relative standard deviation of 6. Recoveries ranged from 95 to 105. Several food products were tested with AOAC Method 982.29, which is currently in use for vitamins D3 and D2, and results were comparable within 6.

scholarly journals Measurement of Plasma Free Metanephrine and Normetanephrine by Liquid Chromatography–Tandem Mass Spectrometry for Diagnosis of Pheochromocytoma

2004 ◽  
Vol 50 (3) ◽  
pp. 603-611 ◽  
Author(s):  
Susan A Lagerstedt ◽  
Dennis J O’Kane ◽  
Ravinder J Singh
Keyword(s):  
Solid Phase ◽  
Atmospheric Pressure Chemical Ionization ◽  
Multiple Reaction Monitoring ◽  
Internal Standard ◽  
Ionization Source ◽  
Deming Regression ◽  
Liquid Chromatography Tandem Mass ◽  
Pressure Chemical Ionization ◽  
Pressure Chemical ◽  
Plasma Free Metanephrines

Abstract Background: Quantification of plasma free metanephrines is usually accomplished by HPLC with electrochemical detection, but sample preparation is labor-intensive and time-consuming, run times are long, and interfering substances sometimes obscure the relevant peaks. The aim of this study was to develop a sensitive and specific LC-MS/MS method for plasma free metanephrines. Methods: After solid-phase extraction, chromatographic separation of normetanephrine (NMN) and metanephrine (MN) was accomplished by use of a cyano analytical column. NMN, MN, d3-NMN, and d3-MN positive ions were detected in the multiple-reaction monitoring mode using the specific transitions m/z 166→134, 180→148, 169→137, and 183→151, respectively, with an atmospheric pressure chemical ionization source. Results: Multiple calibration curves exhibited consistent linearity and reproducibility. Interassay imprecision values (CV; n = 20) for NMN at 0.64, 1.9, and 2.7 nmol/L were 6.6%, 7.8%, and 13%, respectively. Interassay CV for MN at 0.60, 1.2, and 2.1 nmol/L (n = 20) were 9.2%, 6.8%, and 9.8%, respectively. The mean recoveries of NMN and MN relative to the internal standard were 100% and 96%, respectively. The assays were linear between 0.20 and 10.0 nmol/L. Deming regression of HPLC and LC-MS/MS results yielded slopes of 0.93 (95% confidence interval, 0.89–0.98) and 0.89 (0.85–0.93) and y-intercepts of −0.16 and 0.03 nmol/L for NMN (n = 132) and MN (n = 92), respectively. Conclusions: This novel LC-MS/MS approach provides a precise, rapid, and specific alternative method to HPLC for the quantification of the low nanomolar concentrations of free metanephrines in plasma.

scholarly journals Full validation of curcumin analytical method by LC-MS/MS points out that the degree of hemolysis in plasma affects the quantitation: application in dog plasma study

2019 ◽  
Vol 62 (4) ◽  
Author(s):  
Mariana Dolores ◽  
Alma Villaseñor ◽  
Alma Revilla Vázquez ◽  
Helgi Jung ◽  
Victor Hugo Santiago Rios ◽  
...  
Keyword(s):  
Internal Standard ◽  
Daily Practice ◽  
Reaction Monitoring ◽  
Selective Method ◽  
Clopidogrel Bisulfate ◽  
Dog Plasma ◽  
Relative Standard ◽  
Molecular Reaction ◽  
Acquity Uplc

Abstract. Curcumin has gained great attention in the last decades due to its fascinating properties for humans, such as anti-inflammatory or as cytotoxic against cancer. These effects are also claimed for pets such as cats and dogs, where curcumin administration is a daily practice routine. However, curcumin presents poor oral bioavailability, driving scientists to look for new delivery systems. In the last decades, several analytical methods for the quantification of curcumin in plasma have been published. To our knowledge there are no published reports on the effect of the level of hemolysis in the determination of this compound. In the present paper, a highly specific, sensitive and selective method is presented using Molecular Reaction Monitoring (SRM) using positive ionization (ESI+) mode. Curcumin and clopidogrel bisulfate – used as internal standard (IS) – were separated on an Acquity UPLC BECH Shield RP 18 column (1.7µm, 2.1 X 100mm) with 0.1% formic acid in acetonitrile and water in proportion of 60:40 (v/v). The analyte transitions were 369.3→177.06 m/z for curcumin and 322→212.05 m/z for IS. The method was fully validated and showed good linearity (R2 ≥ 0.999) over the range of 3-160 ng/mL. The Relative Standard Deviation (RSD) were less than 6% for intra-and inter-day analysis and recovery spanned 85-95%. We proved that the degree of hemolysis impaired curcumin quantitation. This method was applied to test curcumin bioavailability in both a mucoadhesive nanocapsule formulation and traditional capsules in dogs that attended routine veterinary consultation.Resumen. La curcumina ha ganado gran atención en las últimas décadas debido a sus propiedades terapéuticas para los humanos, como antiinflamatorio o citotóxico contra el cáncer. Estos efectos también se observan en pequeñas especies como gatos y perros, donde la administración de curcumina se ha vuelto una alternativa. Sin embargo, la curcumina presenta una baja biodisponibilidad oral, lo que impulsa a los científicos a buscar nuevos sistemas de administración. En las últimas décadas, se han publicado varios métodos analíticos para la cuantificación de curcumina en plasma. Actualmente, no hay informes publicados sobre el efecto del grado de hemólisis en la determinación de este compuesto. En este trabajo se desarrolló un método específico, sensible y selectivo utilizando el Monitoreo de reacción seleccionado (SRM) en modo de ionización positiva (ESI +). La curcumina y el bisulfato de clopidogrel, utilizado como patrón interno (IS), se separaron en una columna Acquity UPLC BECH Shield RP 18 (1,7 μm, 2,1 X 100 mm) con ácido fórmico al 0,1% en acetonitrilo y agua a una proporción de 60:40 (v/v). Las transiciones de los analitos fueron 369.3 → 177.06 m/z para curcumina y 322 → 212.05 m/z para IS. El método fue validado y demostró ser lineal (r2 ≥ 0.999) en el rango de 3-160 ng/mL. La desviación relativa estándar (RSD) fue inferior al 6% para el análisis intra e interdía y el porcentaje de recuperación fue 85-95%. Se descubrió que el grado de hemólisis afecta la cuantificación de curcumina. El método desarrollado se aplicó para evaluar la biodisponibilidad de curcumina tanto en una formulación de nanocápsulas mucoadhesivas como en cápsulas tradicionales en perros que asistieron a consultas veterinarias de rutina.

scholarly journals Determination of Cholecalciferol (Vitamin D3) in Selected Foods by Liquid Chromatography: NMKL Collaborative Study

2003 ◽  
Vol 86 (2) ◽  
pp. 400-406 ◽  
Author(s):  
Anders Staffas ◽  
Arne Nyman ◽  
K Ask ◽  
E Hermansson ◽  
J S Jacobsen ◽  
...  
Keyword(s):  
Liquid Chromatography ◽  
Standard Deviation ◽  
Fish Oil ◽  
Vitamin D3 ◽  
Collaborative Study ◽  
The Other ◽  
Vitamin D2 ◽  
Cooking Oil ◽  
Relative Standard

Abstract Results are presented from an NMKL (Nordic Committee on Food Analysis) collaborative study of a method for the determination of cholecalciferol (vitamin D3) in foods. The method is based on the addition of an internal standard (vitamin D2), followed by saponification and extraction with n-heptane. The fraction that contains vitamin D2/D3 is separated by preparative normal-phase liquid chromatography (LC), and the analytes are determined by reversed-phase LC with UV detection at 265 nm. The method was tested by 8 participating laboratories. In this study 6 different matrixes were analyzed for cholecalciferol content: milk, liquid infant formula (gruel), cooking oil, margarine, infant formula, and fish oil. The contents varied from 0.4 to 12 μg/100 g. Three matrixes (milk, gruel, and margarine) were fortified with vitamin D3. In the other matrixes, vitamin D3 was added at 3 different levels at the Swedish National Food Administration. The milk was analyzed as a blind duplicate, whereas the other matrixes were analyzed as split-level pairs. The recoveries from the samples with vitamin D3 added varied from 93 to 102%. The repeatability relative standard deviation (RSDr) values for accepted results varied between 2.2% (fish oil) and 7.4% (cooking oil), whereas the reproducibility relative standard deviation (RSDR) values varied between 6.8% (margarine) and 24% (cooking oil).

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