ABSTRACT
The clinical bioanalytical setting is characterized by sample volumes of < 1 ml biological fluid (e.g. plasma, urine), a range of 3-4 decades of concentrations to be quantified and a limit of quantitation in the microg/l-ng/l range for sets of 100-5000 individual samples. Setup of capillary electrophoresis (CE) for routine application in this analytical field was successful for analytes accessible to fluorescence detection by using laser-induced fluorescence (LIF) detection. Empowerment of CE-LIF for routine serial analysis of thousands of samples includes improvement in autosampler techniques, thorough procedures for capillary treatment and particularly more advanced detection technology. Introduction of multi-capillary systems with charge-coupled device cameras and frequency doubled Ar-ion laser (lambda = 257 nm) offers this technique the chance of superiority over classical analytical assays - especially in the field of (new) low volume samples e.g. capillary blood or microdialysate encouraging clinicians to search for meaningful non-invasive samples.
Subject(s)
Aza Compounds , Electrophoresis, Capillary/methods , Fluoroquinolones , Quinolines , Spectrometry, Fluorescence/methods , Anti-Infective Agents/analysis , Ciprofloxacin/analysis , Drug Design , Lasers , Moxifloxacin , Sensitivity and SpecificityABSTRACT
Capillary electrophoresis (CE) with UV laser-induced native fluorescence detection was developed as a sensitive and selective assay for the direct determination of tramadol in human urine without extraction or preconcentration. The main problem in CE is the small inner diameter of the capillary which causes a low sensitivity with instruments equipped with a UV detector. Laser-induced native fluorescence with a frequency doubled argon ion laser at an excitation wavelength of 257 nm was used for the direct assay of tramadol in urine to enhance the limit of detection about 1,000-fold compared to UV absorption detection. The detection system consists of an imaging spectrograph and an intensified CCD camera, which views an illuminated 1.5 mm section of the capillary. This set-up is able to record the whole emission spectra of the analytes to achieve additionally wavelength-resolved electropherograms. In the concentration range of 20 ng/ml-5 microg/ml in human urine coefficients of correlation were better than 0.998. Within-day variation determined on four different concentrations showed accuracies ranging from 90.2 to 108.4%. The relative standard deviation (RSD) was determined to be less than 10%. Day-to-day variation presented accuracies ranging from 90.9 to 103.1% with an RSD less than 8%.
Subject(s)
Analgesics, Opioid/urine , Electrophoresis, Capillary/methods , Spectrometry, Fluorescence/methods , Tramadol/urine , Humans , Lasers , Reproducibility of Results , Sensitivity and SpecificityABSTRACT
We report on spatially resolved simultaneous measurements of temperature and majority species concentrations along a line segment in a premixed laminar H(2)-air flame. The results are obtained from Raman and Rayleigh scattering by using a narrow-band KrF excimer laser and a spectrally and spatially resolving detector system that consists of a high-throughput spectrometer and a gated, intensified, two-dimensional CCD camera. The data presented here are integrated over 100 laser shots. Absolute density profiles of N(2), O(2), H(2)O, and H(2), as well as temperature profiles at various heights through the flame, are presented. A discussion of the required calibration procedures and a summary of the necessary spectroscopic background are also included in this paper.
