Determination of Tryptophan and Kynurenine by LC-MS/MS by Using Amlodipine as an Internal Standard
JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY, cilt.31, sa.2, ss.379-385, 2020 (SCI-Expanded, Scopus)
- Yayın Türü: Makale / Tam Makale
- Cilt numarası: 31 Sayı: 2
- Basım Tarihi: 2020
- Doi Numarası: 10.1021/jasms.9b00007
- Dergi Adı: JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY
- Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, Analytical Abstracts, Chimica, Compendex, EMBASE, MEDLINE
- Sayfa Sayıları: ss.379-385
- Anahtar Kelimeler: tryptophan, kynurenine, amlodipine, LC-MS/MS, PERFORMANCE LIQUID-CHROMATOGRAPHY, HUMAN PLASMA, QUANTITATIVE-ANALYSIS, VALIDATION, METABOLITES, SERUM, ACID, HYDROCHLOROTHIAZIDE, DERIVATIZATION, PHENYLALANINE
- Gazi Üniversitesi Adresli: Evet
Özet
Tryptophan is an essential amino acid that plays an important role in cell metabolism, and kynurenine is its main metabolic pathway. By using ultra-high-performance liquid chromatography coupled to electrospray ionization triple-quadrupole mass spectrometry, tryptophan and kynurenine were determined using amlodipine as an internal standard. The analysis was carried out on an ACE-C18 (4.6 mm X 50 mm, 5 mu m) reversed-phase analytical column using the gradient elution mode. For quantitative determination, amlodipine was used as an internal standard. Detection was performed using multiple reaction monitoring in electrospray ionization mode at m/z 205.1 -> 117.7 and 187.9 for tryptophan, m/z 209.1 -> 146 and 93.9 for kynurenine, and m/z 409.2 -> 294.1 for the internal standard. Good linearity of the analyte to internal standard peak area ratios was seen in the concentration range 1.25-4000 ng/mL for tryptophan and 0.5-1600 ng/mL for kynurenine. The method showed excellent linearity with regression coefficients of 0.99 for kynurenine and 0.996 for tryptophan. The limits of quantification were 0.55 ng/mL for tryptophan and 0.47 ng/mL for kynurenine. The % RSD for all analytes ranged from 0.3 to 3.4% for intraday and 0.4 to 8.9% for interday experiments. A simple LC-MS/MS method has been developed and validated for measuring Kyn and Trp by using an affordable and more easily available internal standard, which is amlodipine.