Direct analysis of complex samples is demonstrated by the at-line coupling of hollow fiber liquid-phase microextraction (HF-LPME) to capillary electrophoresis (CE). The hyphenation of the preparative and the analytical technique is achieved through a 3D-printed microextraction device with an HF located in a sample vial of a commercial CE instrument. The internal geometry of the device guides the CE separation capillary into the HF and the CE injection of the HF-LPME extract is performed directly from the HF lumen. The 3D-printing process ensures uniform dimensions of the devices, their constant position inside the sample vial, and excellent repeatability of the HF-LPME as well as the CE injection. The devices are cheap (∼0.01 €) and disposable, thus eliminating any possible sample-carryover, moreover, the at-line CE analysis of the extract is performed fully autonomously with no need for operator's intervention. The developed HF-LPME/CE-UV method is applied to the determination of acidic drugs in dried blood spot and wastewater samples and is characterized by excellent repeatability (RSD, 0.6-9.6%), linearity (r2, 0.9991-0.9999), enrichment (EF, 29-97), sensitivity (LOD, 0.2-3.4 μg/L), and sample throughput (7 samples/h). A further improvement of selected characteristics of the analytical method is achieved by the at-line coupling of HF-LPME to capillary isotachophoresis (ITP) with electrospray ionization-mass spectrometry (ESI-MS). The HF-LPME/ITP-ESI-MS system facilitates enhanced selectivity, matrix-free analytical signals, and up to 34-fold better sensitivity due to the use of ESI-MS detection and additional on-capillary ITP preconcentration of the HF-LPME extracts.
BACKGROUND: Dialysis patients are at high risk of cardiovascular complications. Pregnancy-associated plasma protein A (PAPP-A) as well as sRAGE (soluble receptor for advanced glycation end products) are new biomarkers related to cardiovascular disease. The aim of our study was to describe their intra- and inter-individual variability. METHODS: The studied group consisted of 21 chronic hemodialysis patients. PAPP-A, sRAGE and selected routine parameters were measured monthly during a 1-year prospective study. RESULTS: Our results show high intra-individual variability of both PAPP-A and sRAGE. Both PAPP-A and sRAGE were closely linked to serum transferrin levels. Additionally, sRAGE was significantly associated with leukocyte count and haemoglobin. CONCLUSION: Our study demonstrates high intra-individual variability of PAPP-A and sRAGE in stable clinical status. This finding could be helpful for further evaluation of the significance of PAPP-A and sRAGE in chronic kidney disease.
- MeSH
- analýza rozptylu MeSH
- biologické markery krev MeSH
- chronické selhání ledvin krev komplikace terapie MeSH
- dialýza ledvin MeSH
- kardiovaskulární nemoci krev etiologie MeSH
- lidé středního věku MeSH
- lidé MeSH
- longitudinální studie MeSH
- počet leukocytů MeSH
- prospektivní studie MeSH
- receptory imunologické krev MeSH
- regresní analýza MeSH
- senioři nad 80 let MeSH
- senioři MeSH
- těhotenský plazmatický protein A metabolismus MeSH
- transferin metabolismus MeSH
- Check Tag
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- senioři nad 80 let MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
