1
|
Meikopoulos T, Begou O, Gika H, Theodoridis G. Dried urine spot (DUS) applied for sampling prior to the accurate HILIC-MS/MS determination of 14 amino acids. Talanta 2024; 269:125489. [PMID: 38096631 DOI: 10.1016/j.talanta.2023.125489] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2023] [Revised: 11/20/2023] [Accepted: 11/24/2023] [Indexed: 01/05/2024]
Abstract
Urine amino acid analysis has proven valuable for an array of clinical or nutritional studies. However, transportation of liquid urine sample shows certain disadvantages, such as possible leakage, need for cold chain and thus higher costs for their transport. Utilization of dried urine spots (DUS) can offer an interesting alternative. In the present study, a method was developed for the determination of 14 amino acids in DUS including the testing of in-house collection device and drying of the sample before analysis. Normal filter paper was tested as the means for sample collection. Absorption and extraction experiments were performed on 3 different types of filter paper, with 3 different extraction solvents and two different solvent volumes. The solvents used were mixtures of common analytical solvents (methanol, water, acetonitrile) using total volumes of 1 mL and 1.5 mL. Finally, 1 mL of acetonitrile: methanol: water 40:40:20 (v/v/v) was chosen as the optimal system. Analysis was performed on a UHPLC-MS system, using stable isotope labeled internal standards. Method validation included the study of limits of detection (LOD) and quantification (LOQ), linearity ranges, precision, matrix effect, extraction recovery, precision, and stability for each analyte. The obtained results were satisfactory, thus enabling application of the proposed method as an alternative to the analysis of liquid urine. Further utilization of DUS can offer advantages by enabling patient centric sampling even in long distances far from the analytical laboratories.
Collapse
Affiliation(s)
- Thomas Meikopoulos
- Laboratory of Analytical Chemistry, Department of Chemistry, Aristotle University of Thessaloniki, 54124, Thessaloniki, Greece; BIOMIC_Auth, Center for Interdisciplinary Research, and Innovation (CIRI-AUTH), Balkan Center, Buldings A&B, Thessaloniki, 10th Km Thessaloniki-Thermi Rd, P.O. Box 8318, GR, 57001, Greece
| | - Olga Begou
- Laboratory of Analytical Chemistry, Department of Chemistry, Aristotle University of Thessaloniki, 54124, Thessaloniki, Greece; ThetaBiomarkers, Center for Interdisciplinary Research, and Innovation (CIRI-AUTH), Balkan Center, 10th Km Thessaloniki-Thermi Rd, P.O. Box 8318, GR, 57001, Greece.
| | - Helen Gika
- BIOMIC_Auth, Center for Interdisciplinary Research, and Innovation (CIRI-AUTH), Balkan Center, Buldings A&B, Thessaloniki, 10th Km Thessaloniki-Thermi Rd, P.O. Box 8318, GR, 57001, Greece; Laboratory of Forensic Medicine and Toxicology, Medical School, Aristotle University of Thessaloniki, 54124, Thessaloniki, Greece
| | - Georgios Theodoridis
- Laboratory of Analytical Chemistry, Department of Chemistry, Aristotle University of Thessaloniki, 54124, Thessaloniki, Greece; BIOMIC_Auth, Center for Interdisciplinary Research, and Innovation (CIRI-AUTH), Balkan Center, Buldings A&B, Thessaloniki, 10th Km Thessaloniki-Thermi Rd, P.O. Box 8318, GR, 57001, Greece; FoodOmicsGR Research Infrastructure, AUTh Node, Center for Interdisciplinary Research, And Innovation (CIRI-AUTH), Balkan Center B1.4, 10th Km Thessaloniki-Thermi Rd, P.O. Box 8318, 57001, Thessaloniki, Greece.
| |
Collapse
|
2
|
Tsikas D. Application of the Bland-Altman and Receiver Operating Characteristic (ROC) Approaches to Study Isotope Effects in Gas Chromatography-Mass Spectrometry Analysis of Human Plasma, Serum and Urine Samples. Molecules 2024; 29:365. [PMID: 38257277 PMCID: PMC10818406 DOI: 10.3390/molecules29020365] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2023] [Revised: 01/08/2024] [Accepted: 01/09/2024] [Indexed: 01/24/2024] Open
Abstract
The Bland-Altman approach is one of the most widely used mathematical approaches for method comparison and analytical agreement. This work describes, for the first time, the application of Bland-Altman to study 14N/15N and 1H/2H (D) chromatographic isotope effects of endogenous analytes of the L-arginine/nitric oxide pathway in human plasma, serum and urine samples in GC-MS. The investigated analytes included arginine, asymmetric dimethylarginine, dimethylamine, nitrite, nitrate and creatinine. There was a close correlation between the percentage difference of the retention times of the isotopologs of the Bland-Altman approach and the area under the curve (AUC) values of the receiver operating characteristic (ROC) approach (r = 0.8619, p = 0.0047). The results of the study suggest that the chromatographic isotope effects in GC-MS result from differences in the interaction strengths of H/D isotopes in the derivatives with the hydrophobic stationary phase of the GC column. D atoms attenuate the interaction of the skeleton of the molecules with the lipophilic GC stationary phase. Differences in isotope effects in plasma or serum and urine in GC-MS are suggested to be due to a kind of matrix effect, and this remains to be investigated in forthcoming studies using Bland-Altman and ROC approaches.
Collapse
Affiliation(s)
- Dimitrios Tsikas
- Core Unit Proteomics, Institute of Toxicology, Hannover Medical School, 30623 Hannover, Germany
| |
Collapse
|