scholarly journals Analysis of Methylmalonic Acid in Plasma by Liquid Chromatography–Tandem Mass Spectrometry

2006 ◽  
Vol 52 (4) ◽  
pp. 754-757 ◽  
Author(s):  
Anne Schmedes ◽  
Ivan Brandslund
Keyword(s):  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
Tandem Mass Spectrometry ◽  
Formic Acid ◽  
Methylmalonic Acid ◽  
Cobalamin Deficiency ◽  
Tandem Mass ◽  
Simple Method ◽  
Chromatography Tandem Mass Spectrometry ◽  
Liquid Chromatography Tandem Mass

Abstract Background: Methylmalonic acid (MMA) is a biochemical marker for cobalamin deficiency, particularly in cases where the cobalamin concentration is moderately decreased or in the low-normal range. Liquid chromatography–tandem mass spectrometry (LC-MS/MS) with electrospray ionization is a rapid, robust method that has been used in MMA analysis. We developed a simple method combining solid-phase extraction (SPE) and derivatization to prepare serum or plasma for LC-MS/MS analysis of MMA. Methods: Deuterated internal standard d3-MMA was added to serum or plasma before SPE on strong anion-exchange (SAX) columns. After elution with HCl–butanol (10:90 by volume) and addition of 1 g/L formic acid, the samples were simultaneously derivatized and evaporated by heating to 70 °C for 15 min followed by 54 °C overnight in uncapped vials. Acetonitrile and 1 g/L formic acid were added to the samples before injection into the LC-MS/MS system. MMA and d3-MMA were quantified in the multiple-reaction monitoring mode. Calibrators were prepared in serum by the standard addition method. Results: The MMA assay was linear up to 200 μmol/L. Interassay CVs were 6.7%, 5.0%, and 5.0% for mean concentrations of 0.15, 0.36, and 0.65 μmol/L, respectively. Conclusions: Our simplified sample preparation and derivatization method is suitable for use in MMA analyses. MMA elutes with the derivatization reagent, and derivatization and evaporation are performed simply by leaving the uncapped vials in a heating block overnight. The method shows good linearity and precision.

scholarly journals Liquid chromatography – tandem mass spectrometry method for the determination of ten tetracycline residues in muscle samples

2015 ◽  
Vol 59 (3) ◽  
pp. 345-352 ◽  
Author(s):  
Anna Gajda ◽  
Andrzej Posyniak
Keyword(s):  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
Tandem Mass Spectrometry ◽  
Formic Acid ◽  
Solid Phase ◽  
Acid Extraction ◽  
Tandem Mass ◽  
Chromatography Tandem Mass Spectrometry ◽  
Liquid Chromatography Tandem Mass

Abstract A liquid chromatography – tandem mass spectrometry (LC-MS/MS) method for the determination of oxytetracycline (OTC), 4-epi oxytetracycline (4-epi OTC), tetracycline (TC), 4-epi tetracycline (4-epi TC), chlortetracycline (CTC), 4-epi chlortetracycline (4-epi CTC), doxycycline (DC), minocycline (MINO), methacycline (META) and rolitetracycline (ROLI) residues in muscles was developed. The procedure consisted of an oxalic acid extraction followed by protein removal with trichloroacetic acid. Further solid phase clean-up on polymeric (Strata X) reversed phase columns was performed to obtain an extract suitable for LC-MS/MS analysis. The tetracyclines were separated on a C 18 analytical column with mobile phase consisting of 0.01% formic acid in acetonitrile and 0.01% formic acid in water in gradient mode. The method was validated according to the Commission Decision 2002/657/EC. The recoveries of all target compounds were 91.8% – 103.6%. The decision limits were from 109.0 to 119.8 μg/kg and detection capability varied within the range of 122.2 to 137.6 μg/kg, depending on the analyte.

Measurement of citrate in urine using liquid chromatography tandem mass spectrometry: comparison with an enzymatic method

2005 ◽  
Vol 42 (5) ◽  
pp. 357-363 ◽  
Author(s):  
BG Keevil ◽  
L Owen ◽  
S Thornton ◽  
J Kavanagh
Keyword(s):  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
Tandem Mass Spectrometry ◽  
Formic Acid ◽  
Ammonium Acetate ◽  
Enzymatic Assay ◽  
Tandem Mass ◽  
Chromatography Tandem Mass Spectrometry ◽  
Liquid Chromatography Tandem Mass ◽  
Urinary Citrate

Background: Measurement of urine citrate is used to assess the risk of further urinary stone formation and to assess the benefit of treatment in affected individuals. We wanted to develop a simple and rapid liquid chromatography tandem mass spectrometry (LC-MS/MS) method for the analysis of urinary citrate and to compare it with our current enzymatic assay. Methods: For the LC-MS/MS assay, samples were prepared in a deep-well block by adding 10 µL of urine and 20 µL of internal standard to 400 µL of water. After mixing, 3 µL of the diluted sample was injected into the LC-MS/MS system. An LC system was used to isocratically elute a C18 column (50 x 2.1 mm) with 0.4 mL/min water containing 2 mmol/L ammonium acetate and 0.1% (v/v) formic acid. A step gradient of 100% methanol containing 2 mmol/L ammonium acetate and 0.1% (v/v) formic acid was used to wash the column. The retention times were 1.4 min for citrate and 1.4 min for d4-citrate. Cycle time was 4.0 min, injection to injection. The analytes were monitored using a tandem mass spectrometer operated in multiple reaction monitoring mode using the following transitions, citrate m/ z 191.0> 111.0 and d4-citrate m/ z 195.0> 113.0. Results: Within and between-batch coefficients of variation were <3% over the range 480-3800 µmol/L. The lower limit of quantification was 24.0 µmol/L. Regression analysis showed LC-MS/MS = 0.8781 (enzymatic assay) + 102.5, r = 0.964, n = 73. Conclusions: We have developed a simple LC-MS/MS method for urinary citrate measurement that shows acceptable performance.

scholarly journals ANALYSIS OF 6-MERCAPTOPURINE AND 6-METHYLMERCAPTOPURINE IN DRIED BLOOD SPOTS USING LIQUID CHROMATOGRAPHY-TANDEM MASS SPECTROMETRY AND ITS APPLICATION IN CHILDHOOD ACUTE LYMPHOBLASTIC LEUKEMIA PATIENTS

2017 ◽  
Vol 10 (9) ◽  
pp. 120 ◽  
Author(s):  
Supandi Supandi ◽  
Yahdiana Harahap ◽  
Harmita Harmita ◽  
Rizka Andalusia ◽  
Marlina Ika
Keyword(s):  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
Tandem Mass Spectrometry ◽  
Formic Acid ◽  
Maintenance Phase ◽  
Dried Blood Spots ◽  
Tandem Mass ◽  
Blood Spots ◽  
Chromatography Tandem Mass Spectrometry ◽  
Liquid Chromatography Tandem Mass

  Objective: To analyze and validate 6-mercaptopurine (6-MP) and 6-methylmercaptopurine (6-MMP) in dried blood spots (DBS) using liquid chromatography-tandem mass spectrometry (LC/MS-MS).Methods: Bio-sampling dried blood spot with DBS-CAMAG® paper diameter of 8 mm and extracted with acetonitrile-methanol (1:3) containing internal standard 5-fluorouracil (5-FU). Separation was performed with C18 column Acquity® 1.7 μm (2.1 mm × 100 mm), with a mobile phase mixture of 0.1% formic acid in water 0.1% formic acid in acetonitrile with gradient elution and flow rate 0.2 ml/min. Mass detection was Waters Xevo TQD with positive electrospray ionization (ESI) for 6-MP, 6-MMP and negative ESI for 5-FU in multiple reaction monitoring modes. The ions of 6-MP was detected at m/z 153.09->119.09, 6-MMP at m/z 167.17->126.03, and 5-FU at m/z 129.15->42.05.Results: This method fulfill the requirements of selectivity, linearity, lower limit of quantification, accuracy, precision, carry-over, matrix effects, and stability which refers to the european medicines agency (EMEA) guidelines. The linearity of 0.99 was 26-1000 ng/mL for 6-MP and 6-MMP, respectively. The validated method was applied to two childhood ALL maintenance phase. Retrieved 6-MP levels of 10.37 pmol/8×108 erythrocytes, respectively. The levels of 6-MMP gained 16.59 pmol/8×108 erythrocytes, respectively.Conclusion: The developed LC/MS-MS method is valid to analysis 6-MP and 6-MMP in DBS simultaneous in vitro according to EMEA guidelines. The method was successfully applied to authentic capillary blood samples from two childhood patients with ALL in the maintenance phase.

scholarly journals Simultaneous Analysis of 6-Mercaptopurine, 6-Methylmercaptopurine, and 6-Thioguanosine-5’-monophosphate in Dried Blood Spot Using Ultra Performance Liquid Chromatography Tandem Mass Spectrometry

2018 ◽  
Vol 18 (3) ◽  
pp. 544 ◽  
Author(s):  
Supandi Supandi ◽  
Yahdiana Harahap ◽  
Harmita Harmita ◽  
Rizka Andalusia
Keyword(s):  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
Tandem Mass Spectrometry ◽  
Formic Acid ◽  
Ultra Performance Liquid Chromatography ◽  
Dried Blood Spot ◽  
Tandem Mass ◽  
Chromatography Tandem Mass Spectrometry ◽  
Liquid Chromatography Tandem Mass ◽  
Blood Spot

6-Mercaptopurine is a chemotherapeutic agent of the antimetabolite class. This study aims to analyze simultaneous validation of 6-mercaptopurine (6-MP), 6-methylmercaptopurine (6-MMP), and 6-thioguanosine-5’-monophosphate (6-TGMP) in dried blood spot (DBS) using ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). An accurate volume of 60 μL blood was spotted onto DBS-CAMAG paper and then extracted using methanol 90% (v/v) containing an internal standard of 5-fluorouracil (5-FU). Separation was performed using a Waters Acquity UPLC BEH AMIDA column 1.7 μm (2.1 x 100 mm) with a mobile phase mixture of 0.2% (v/v) formic acid in water−0.1% (v/v) formic acid in acetonitrile-methanol with gradient elution and flow rate of 0.2 mL/min. Mass detection was done using Waters Xevo TQD with positive electrospray ionization (ESI) for 6-MP, 6-MMP, 6-TGMP and negative ESI for 5-FU, in multiple reaction monitoring mode. Detection rates of 6-MP, 6-MMP, 6-TGMP and 5-FU were m/z 153.09 > 119.09; 167.17 > 126.03; 380.16 > 168.00); 129.09 > 42.05, respectively. This method is linear across the range 25.5–1020 ng/mL for 6-MP, 6-MMP and 6-TGMP. This method is valid for the in vitro simultaneous analysis of 6-MP, 6-MMP and 6-TGMP in DBS, based on European Medicine Agency guidelines.

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