Subject(s)
Group Practice/organization & administration , Medical Records Systems, Computerized/organization & administration , Systems Integration , Efficiency, Organizational , Managed Care Programs/organization & administration , Models, Organizational , Organizational Innovation , Practice Management, Medical , United StatesABSTRACT
A quantitative method has been developed for the determination of EDTA in human plasma and urine. The samples are prepared with automated anion-exchange solid-phase extraction using 100 microL of human plasma. The extracts are analyzed by capillary electrophoresis/mass spectrometry using selected reaction monitoring in the negative ion mode. Large-volume injections (10% of the CE capillary volume) are used to improve the concentration level of detection via field-amplified sample injection. The first reported validation of a CE/MS/MS technique was carried out for this method. Using a 13C stable-label isotope for the internal standard, the lower level of detection and lower level of quantitation were determined to be 7.3 and 14.6 ng/mL EDTA in human plasma, respectively. The injection precision had a relative standard deviation (RSD) of 6.1%. The intra-assay precision was less than 15% RSD. The intra-assay accuracy was less than +/- 12% bias from the nominal concentration. The interassay precision was less than 18% RSD and the interassay accuracy was less than +/- 9% bias from the nominal concentration.
Subject(s)
Blood Chemical Analysis , Edetic Acid/analysis , Electrophoresis, Capillary/methods , Mass Spectrometry/methods , Urinalysis , Humans , Reproducibility of Results , Sensitivity and SpecificityABSTRACT
An automated extraction procedure using solid-phase extraction (SPE) disk technology was developed for the qualitative and quantitative determination of ethylenediaminetetraacetic acid (EDTA) in water samples. The procedure involves conversion of all free and chelated EDTA present into the nickel EDTA chelate followed by extraction on strong anion exchange extraction disks, A 5 mL water sample is extracted and concentrated to 30 microL. This extract is then analyzed by capillary electrophoresis (CE) using ion spray-tandem mass spectrometry (MS) for selective detection. An amine-coated capillary column is used to separate anions using negative voltage and high electroosmotic flow. A self-aligning liquid junction is used as the CE/MS interface. The sample is injected using field amplification for enhanced concentration detection limits down to 0.15 microgram/L. This detection limit is about five times lower than any report we have found in the literature and provides the unique specificity afforded by mass spectrometry. Total sample preparation and run time was forty minutes per sample, including evaporation steps and capillary rinsing between runs. A tray of 24 vials, including samples and standards, was analyzed for these experiments and was easily finished within one day. These experiments demonstrate that CE/MS can be a rugged, quantitative technique, which, with proper sample preparation and focusing techniques, can compete with the concentration sensitivity of established analytical methods.
Subject(s)
Chelating Agents/chemistry , Edetic Acid/analysis , Electrophoresis, Capillary , Mass Spectrometry , Nickel , Water Pollutants, Chemical/analysis , Water/chemistry , Molecular StructureABSTRACT
A simple self-aligning liquid junction-electrospray interface for coupling a capillary electrophoresis (CE) system to an atmospheric pressure ionization (API) mass spectrometer (CE-MS) was developed. In contrast to previous liquid junction interfaces, the self-aligning liquid junction interface simplifies the precise alignment of the CE capillary and the sprayer needle and uses a positive make-up flow. Several capillary CE-MS applications were run using both the self-aligning liquid junction interface and the widely used sheath flow interface for comparison purposes. The electrospray stability of the self-aligning liquid junction interface is consistently better even when non-volatile electrolyte solutions are used. At first, some band broadening was obtained with the self-aligning liquid junction interface. Experiments with different CE buffer systems suggested that this band broadening was caused by the materials used in constructing the interface. By using a more inert material for the sprayer needle, the self-aligning liquid junction exhibits excellent electrophoretic resolution, comparable sensitivity, and higher signal-to-noise ratios when run under the same conditions as the sheath flow interface.
Subject(s)
Adrenergic beta-Agonists/urine , Electrophoresis, Capillary/methods , Mass Spectrometry/methods , Adrenergic beta-Agonists/chemistry , Albuterol/chemistry , Albuterol/urine , Clenbuterol/chemistry , Clenbuterol/urine , Electrophoresis, Capillary/instrumentation , Ephedrine/chemistry , Ephedrine/urine , Fenoterol/chemistry , Fenoterol/urine , Isoproterenol/chemistry , Isoproterenol/urine , Mass Spectrometry/instrumentation , Metaproterenol/chemistry , Metaproterenol/urine , Terbutaline/analogs & derivatives , Terbutaline/chemistry , Terbutaline/urineABSTRACT
The enantiomers of both terbutaline and ephedrine were separated by capillary electrophoresis using electrolyte solutions of heptakis(2,6-di-O-methyl)-beta-cyclodextrin in low pH buffers. The analytes were detected by ion spray mass spectrometry using selected ion monitoring or by selected reaction monitoring in the positive ion mode. Both the free drug enantiomers and the noncovalent enantiomer-cyclodextrin inclusion complexes for terbutaline can be detected simultaneously using this method. The feasibility of using CE/MS for chiral purity determination is demonstrated. In addition, a comparison of UV detection versus mass spectrometry detection for a spiked urine sample is included to demonstrate the selectivity and sensitivity advantages of the mass spectrometer as a CE detector.
