High-Throughput Serum 25-Hydroxy Vitamin D Testing with Automated Sample Preparation
Elapsed time (min) % Mobile phase B Flow rate (mL/min) 0 30 1.0 0.900 80 1.0 0.901 92 1.0 1.150 92 1.0 1.160 95 1.0 1.170 95 1.7 1.460 95…
BIOCHEMISTRY
Quantitation of Ubiquinone (Coenzyme Q10) in Serum/Plasma Using Liquid Chromatography Electrospray Tandem Mass Spectrometry (ESI-LC-MS/MS)
Calibrator Volume of stock standard (μL) Volume of ethanol (μL) Final concentration (μg/mL) Final dilution 6 200 – 6.0 – 5 200 200 3.0 1:2 4 333 667 2.0 1:3…
Quantitation of Parathyroid Hormone in Serum or Plasma by Liquid Chromatography-Tandem Mass Spectrometry
Calibrator concentration pg/mL Intermediate 50 ng/mL std (mL) Stripped serum (mL) 0 0 250 50 0.25 249.75 100 0.50 249.5 300 1.50 248.5 600 3.0 247.0 1000 5.0 245.0 2000…
Quantitation of Free Metanephrines in Plasma by Liquid Chromatography-Tandem Mass Spectrometry
To make Use source solution Volume of source solution Volume of 10 mM ammonium phosphate pH 6.5 (mL) Metanephrine concentration (pg/mL) Normetanephrine concentration (pg/mL) Std7 Working solution 100 μL QS…
Quantitative Organic Acids in Urine by Two Dimensional Gas Chromatography-Time of Flight Mass Spectrometry (GCxGC-TOFMS)
Pre- Name Synonym Supp. Mol. wt. Acetoacetic Li salt Lithium acetoacetate Sigma 108.00 N– Acetylaspartic Aldrich 175.10 N– Acetyltyrosine Sigma 223.20 Aconitic cis-Aconitic Sigma 174.10 Adipic Sigma 146.14 Benzoic-Na salt …
Quantification of 1,25-Dihydroxyvitamin D2 and D3 in Serum Using Liquid Chromatography-Tandem Mass Spectrometry
2.4 Internal Standards 1. 1α,25-Dihydroxyvitamin D3 (26,26,26,27,27,27-d6), Medical Isotopes, Pelham, NH. 2. 1α,25-Dihydroxyvitamin D3 (26,26,26,27,27,27-d6), Medical Isotopes, Pelham, NH. 3. Preparation of individual standard stocks (20 μg/mL):…
Quantitation of 25-OH-Vitamin-D2 and 25-OH-Vitamin-D3 in Urine Using LC-MS/MS
Calibrator Vol. of 200 ng/mL stock added (μL) Vol. of MeOH added (μL) Urine added (μL) Total vol. (mL) Approx. final conc. (pg/mL)a 1 0 750 99,250 100 0 2…
Quantification of Dehydroepiandrosterone, 11-Deoxycortisol, 17-Hydroxyprogesterone, and Testosterone by Liquid Chromatography-Tandem Mass Spectrometry (LC/MS/MS)
Calibrator Tertiary combo standards (μL) Secondary combo standards (μL) Serum volume Final conc. (ng/dL) Blank 10 mL 1 10 μL qs to 10 mL 10 2 20 μL qs to…
Quantitation of S-Adenosylmethionine and S-Adenosylhomocysteine in Plasma Using Liquid Chromatography-Electrospray Tandem Mass Spectrometry
Fig. 1 HPLC -ESI-MS/MS ion chromatogram of SAM (m/z 399.1 > 250.1), SAH (m/z 385.1 > 136.1), SAM-D3 (m/z 402.1 > 250.1) and SAH-D4 (m/z 389.1 > 138.1). Concentration of SAM and SAH is 95 nM and 41…
Urine Purine Metabolite Determination by UPLC-Tandem Mass Spectrometry
Analyte Stock solution [Expected] pH, Max UV wavelength ε max × 10−3 Adenine 30 mg in 100 mL Buffer A 2.2 mM pH 6–8, 260 nm 13.3 Xanthinea 12 mg in 1…
