Flow scintillation analyzer

RPLC analysis utilizing a Cig column has been used for the analyzing of radiolabeled C tris(l,3-dichloro-2-propyl)phosphate (TDCP) from skin samples from mouse exposed to TDCP and DBDO. In the analysis of radiolabeled DBDPO, a Cg column was used. In the previous analysis, a gradient elution with water and acetonitrile was applied, while in the latter, isocratic conditions were used. In both cases, a flow scintillation analyzer was used for detection. ... 

In coupling HPLC to spectroscopy, LC-MS(MS) coupling is the favorite. LC-FTIR, LC-NMR, LC-ICP and LC-AAS are fighting to at least enter the research laboratories. For difficult analytical purposes LC-NMR-MS(MS) or LC-NMR-MS-FSA (FSA Flow Scintillation Analyzer) is coming. 

HPLC. Separation of lipids was carried out on a HPLC (Waters Associates, Milford, MA), using a UV detector (Waters 2487) at 205 nm and a flow scintillation analyzer (150TR, Packard Instruments, Downers Grove, IL) to de-... 

The HPLC equipment is a Perkin-Elmer Nelson Model 1022 Plus Chromatograph, connected to a Perkin-Ehner series 200 LC Pump, a LC295 UV/VIS detector, a 7125 BIO injector with a 20-pL loop, and a Canberra Packard Elow Scintillation Analyzer 500 TR Series, with a 0.5-mL flow cell. The system is interfaced with a Compaq Prolinea 5100 computer, using a Canberra Packard ELO-ONE software for system control and data processing. The RP-HPLC columns are Pecosphere Ci8, 5 jam, 30 X 3 mm i.d. (SGE Inc.), with a 5- im C18 guard column (SGE Inc.). Mobile phase is a mixture of methanol water acetic acid (85 15 0.1), and the elution of metabolites is done at a constant flow rate of 0.8 mL/min. Absorbance values are measured at 204 nm. Liquid scintillation cocktail (Ultima Ho M, Canberra Packard) is mixed with the eluent at a 1 2 (eluent(LSC) ratio. Retention times of AEA and arachodonic acid (AA) are 3.2 and 4.5 min, respectively. The concentration of AA is calculated from radioactivity of peak area, and FAAH specific activity is expressed as pmol AA released/min/mg protein. 

Figure 8. Photograph of the fully automated total Tc analyzer instrument in the laboratory. The labeled components are (A) robotic autosampler (B) microwave digestion unit (C) fluid handling components for sample injection, automated standard addition, sample acidification/digestion (D) separation fluidics including syringe pumps, flow reversal, and diversion valves (E) separation column (F) flow scintillation detector and (G) control computer with automation software. Reproduced with permission from the Handbook of Radioactivity Analysis, Second Edition Chapter 14, page 1152. Copyright...

A variety of assays have been developed to quantify phagocytic activity. These include direct microscopic visualization (2,3), spectrophotometric evaluation of phagocytized paraffin droplets containing dye (4), scintillation counting of radiolabeled bacteria (5), fluorometric (6), and flow cytometric analysis of fluorescent particles (7-13). The flow cytometric assay offers the advantage of rapid analysis of thousands of cells and quantification of the internalized particle density for each analyzed cell. The assay may be performed with purified leukocyte preparations (7-13) or anficoagulated whole blood (14,15). 

These were attached to a fraction collector, whose timing mechanism was altered to allow continuous sampling of 28 separate diffusion cells with increased sample and timing capacity. Radiolabeled drugs were used and were measured in a liquid scintillation counter directly interfaced to a computer network. We describe the details of this system which enable us to conduct reproducible flow-through diffusion experiments, assay the samples, and analyze the data quickly and efficiently. 

Figure 6.7 WDS apparatus, which includes the X-ray tube, specimen, primary collimator, analyzing crystal, flow counter, auxiliary collimator and scintillation counter.

Fig. 2. Separation of artificial mixtures of nonradioactive and radioactive standards. Fro files of radioactive and nonradioactive standards recorded simultaneously by a two-pen chart recorder connected to the UV detector and liquid scintillation flow monitor. The analyzed sample contained 75 nmoles of each nonradioactive and 80-100 picomoles of radioactive standards.

In many tracer applications it is not necessary to measure the absolute concentration of the tracer in a sample or in a material flow. In such cases a scintillation detector accompanied by a single-channel pulse height analyzer is a sufficient device. 

The system used in conventional wavelength dispersive spectrometry generally consists of an X-ray tube, an analyzing crystal, and detector (scintillation or gas flow proportional counter) as shown in Fig. 1.9. 

DCEMS together with low-temperature and in-field measurements require much more sophisticated experimental equipment. Gas counters, scintillation detectors, electron multipliers (Channeltron, Ceratron), surface barrier silicon semiconductor detector, and electron energy analyzers belong to the most frequently used detectors applied in CEMS and CXMS, respectively. Differences among individual constructions can be found in Ref. 123. Commercially available version of CEMS/CXMS spectrometer is depicted in Fig. 18.36 [127]. Device is based on 27t proportional continuous gas flow counter for room-temperature zero-magnetic field measurements. 

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