Biomedical subjects

G Rozing

Publications and source records attributed to G Rozing.

5 recordsLinked to original sources

PubMed2006

Very small injected samples to study chloroquine and quinine in human serum using capillary-LC and native fluorescence.

A comparison between HPLC with conventional fluorescence detection and capillary-LC (microHPLC) with native laser-induced fluorescence (LIF) detection was done to determine chloroquine (CQ) and quinine (Q) in human serum. HPLC experiments were run with parameters of the conventional fluorimeter set at the highest level of sensitivity. Results were compared with those obtained on microHPLC coupled to a ZETALIF (He-Cd 325 nm) detector which provided a 50-fold increase in sensitivity. In microHPLC-LIF injection volumes were 200 nL instead of 10 microL in conventional HPLC. The separation was completed within 3 min (6 min on HPLC). The limit of detection on microHPLC-LIF was 1.9 and 1.3 fmol for CQ and Q, respectively. Both experiments were validated on serum samples. The mean recovery was more than 95% for CQ and Q. The intra- and inter-day precision and accuracy were found to be within the acceptable limits (<10%).

Antimalarials↗

PubMed2001

Capillary electrochromatography-laser-induced fluorescence method for separation and detection of dansylated dialkylamine tags in encoded combinatorial libraries.

LC-fluorescence and LC-MS methods have been previously reported for use in decoding bead-based combinatorial libraries. We present the use of capillary electrochromatography (CEC) for highly selective decoding in combination with laser-induced fluorescence (LIF) detection for high sensitivity. The results are compared to prior data obtained using HPLC with fluorescence detection. The use of CEC shows promise for miniaturization and multiplexing for future applications, and the use of LIF detection can allow for detection at sub-pmol amounts.

Amines↗

PubMed2001

Recent applications of capillary electrochromatography.

A review is presented of the most important recent applications of capillary electrochromatography (CEC) for the analysis of acidic, basic, and neutral compounds, of biomolecules, environmental substances, natural products, pharmaceuticals, and chiral compounds. Packed-column CEC (packed-CEC), open-tubular (OT-CEC), as well as pressure-assisted CEC (pseudo-CEC) are hereby considered. Papers published between July 1999 and April 2001 were taken into account. Applications before July 1999 have been reviewed in Electrophoresis 1999, 20, 3027-3065.

Chromatography, Micellar Electrokinetic Capillary↗

PubMed2000

High temperature and temperature programming in capillary electrochromatography.

In electrochromatography, solvent electrophoretic mobility and solute partitioning are temperature dependent processes. If temperature variations are controlled, solute selectivity and analysis times can be tailored. In this study the feasibility of temperature programming in capillary electrochromatography (CEC) was demonstrated using a reversed-phase CEC mode. The outcome of programmed separations was compared with isothermal, isocratic and isorheic (constant flow) separations. The combined effects of column temperature and mobile phase flow-rate changes during the separation run, resulted in up to a 50% reduction in the separation run time, without adversely affecting the quality of separation. For capillary electrochromatography, temperature programming may be a valuable alternative to solvent programming modes because of the great technical difficulties associated with carrying out solvent gradient elution.

Electrophoresis, Capillary↗

PubMed1999

Integrated approach to the multidimensional analysis of complex biological samples by microseparation techniques. Analysis of glycoprotein factor associated with cancer cachexia.

Microanalytical separation techniques including capillary liquid chromatography, capillary electrophoresis and capillary electrochromatography are suitable for detection of diagnostically important changes in the metabolic profiles of biological fluids. A prototype instrument was employed to serve as an integrated platform for the analysis of urine sample from patients suffering from cancer cachexia. The instrument provides for convenient, rapid and efficient multidimensional approach towards method development which would facilitate simultaneous analysis of complex biological mixtures by the above techniques.

Cachexia↗