Quantitative Measurement of Plasma Free Metanephrines by a Simple and Cost-Effective Microextraction Packed Sorbent with Porous Graphitic Carbon and Liquid Chromatography-Tandem Mass Spectrometry

Abstract

Plasma free metanephrines are widely used for the diagnosis of pheochromocytoma and paraganglioma (PPGL), yet quantifying metanephrines using a simple and cost-effective approach may be challenging due to preanalytical and analytical constraints. In this study, we established and validated a new method for quantitative measurement of plasma free metanephrines based on microextraction by packed sorbent (MEPS) with porous graphitic carbon (PGC) and liquid chromatography-tandem mass spectrometry (HILIC-MS/MS). The elution step was fully compatible with HILIC mode without evaporation and reconstitution. The analytes were well resolved, and potential interferences (54 substances) were investigated. This method was linear from 24.7–2717 pg/mL for metanephrine (MN) and 24.5–4010 pg/mL for normetanephrine (NMN) with a coefficient of determination (R2) higher than 0.994. The limit of MN and NMN detection were 12.4 pg/mL and 12.3 pg/mL, respectively. The intra- and interassay impressions were ≤12.8% for spiked quality controls and ≤13.6% for commercial quality controls; the method recoveries ranged within 88.0–109.0%, respectively. The area under the receiver operating characteristic (ROC) curve was 0.848 ± 0.047 for MN and 0.979 ± 0.021 for NMN. Validation that was performed by comparing clinical specimens with various biochemical results showed that plasma free metanephrines in a seated position had comparable sensitivity and lower specificity to urinary free metanephrines, which could be compensated by combining other biochemical tests. The newly developed MEPS method resulted as a time-saving, reliable, and cost-effective microextraction technique that can be applied for a successful screening of PPGL.

Solid Phase-Based Microextraction Techniques in Therapeutic Drug Monitoring

“…It should be noted that the MEPS technique was used by Xiong et al, who developed two methods, one for the determination of catecholamines and metanephrines in urine [23] and another for the quantification of metanephrines in plasma [24], with the objective of being applied in routine clinical laboratories for the diagnosis and screening of pheochromocytoma and paraganglioma neuroendocrine tumors.…”

Mikroekstrakcija čvrstom fazom – inovativni pristup u bioanalitičkim istraživanjima

“…52 Nadalje, tehnikom MEPS postignuta je iznimna osjetljivost (LOD vrijednosti i do 0,12 µg l −1 ) za tumorske biomarkere, čime je omogućeno ranije postavljanje dijagnoze te posljedično bolji ishodi liječenja pacijenata. 53,54 Tehnika MEPS vrlo je pogodna za rukovanje s malim volumenima uzoraka krvi (25-50 µl), što ju čini prikladnom tehnikom u pretkliničkim farmakokinetičkim studijama jer doprinosi poštivanju etičkih načela o upotrebi laboratorijskih životinja u biomedicinskim istraživanjima. 55 Uz to, MEPS pruža nove mogućnosti za terapijsko praćenje lijekova kod novorođenčadi, male djece i kritično bolesnih pacijenata.…”

Porous Inorganic Materials for Bioanalysis and Diagnostic Applications

“…Three biomarkers (α-2-macroglobulin, complement C4-B, and α-1-antitrypsin) were significantly altered with the occurrence and progression of bladder cancer. Porous materials incorporated with downstream MS techniques have also been reported to play key roles in diagnosing pheochromocytoma, paraganglioma, serous ovarian cancer, peritoneal cancer, prostate cancer, and small cell lung cancer. , …”

“…Porous materials incorporated with downstream MS techniques have also been reported to play key roles in diagnosing pheochromocytoma, paraganglioma, serous ovarian cancer, peritoneal cancer, prostate cancer, and small cell lung cancer. 180,181 Other diseases have also been explored using the porous material-assisted MS approach. For instance, chronic unpredictable mild stress is a common complex psychiatric disorder with unclear pathophysiological mechanisms.…”