Liquid scintillation spectrometer

Analytical Methods. Liquid scintillation counting (LSC) was done using Packard Models 3375 and 3380 Liquid Scintillation Spectrometers equipped with automatic external standards. Solid samples were combusted in a Packard model 306 Sample Oxidizer prior to LSC analysis. 

Horrocks, D. L., Low-Level Alpha Disintegration Rate Determinations with a One-Multiplier Phototube Liquid Scintillation Spectrometer,... 

Procedures for pretreatment of soil samples and synthesis of sample benzene for 14C analysis had been described in Chen et al. (2002b). Sample benzene was often left for 3-4 weeks to allow any radon with half-life of 3.82 days that may be present to decay. 14C activity of the CgFL was then determined using a 1220-QUANTULUS ultralow-level liquid scintillation spectrometer manufactured by WALLAC Company, Sweden. The 14C analyses were conducted at the Guangzhou Institute of Geochemistry, CAS. Results are reported as A14C, in parts per thousand of the 14C/12C ratio from that of the standard (oxalic acid decay corrected to 1950) (Stuiver and Po-lach 1977), and corrected for bomb 14C (Chen et al. 2002b), where ... 

Picer et al. [49] described a method for measuring the radioactivity of labelled DDT contaminated sediments in relatively large volumes of water, using a liquid scintillation spectrometer. Various marine sediments, limestone and quartz in sea water were investigated. External standard ratios and counting efficiencies of the systems investigated were obtained, as was the relation of efficiency factor to external standard ratios for each system studied. 

The washed-precipitate, containing antibody-bound morphine, is dissolved in NCS-solubilizer, and the radioactivity is counted with the help of a Packard-Iri-card Liquid Scintillation Spectrometer,... 

The mixture was then treated with 5 ml of alkaline hydroxyl-amine reagent ( 20 ml hydroxylamine hydrochloride titrated to pH 13 with 3.5M NaOH ) for 5 min and the protein precipitated with 5% trichloroacetic acid. After centrifuging ( 5000 g ) for 5 min the supernatant was carefully decanted and the precipitate washed twice with 10-ml aliquots of absolute ethanol. The material was then dissolved in 1 ml, of 0.2M NaOH, mixed with 10 ml of Insta-gel scintillator ( Packard Instrument (Pty) Ltd.), and the radioactivity counted in a Packard Tri Carb Liquid Scintillation Spectrometer. 

Bjomstad HE, Oughton DH, Salbu B. 1992. Determination of aluminum-26 using a low-level liquid scintillation spectrometer. Analyst 117 435-438. 

Quantitative determinations were reported by densitometry [63,72] or, in the case of Relabelled compounds, by scraping or cutting the chromatograms into strips and measuring the radioactivity in a liquid scintillation spectrometer [44,70]. 

Pullen, B.P. 1986. Cherenkov counting of 40K in KC1 using a liquid scintillation spectrometer../. Chem. Educ. 63 971-976. 

The enzymatic radioassay method for the analysis of acetylcholine and choline in brain tissue has been reported by Reid et al. [210]. The method describes the determination of nanogram amounts of acetylcholine and choline in as little as 10 mg of brain tissue, involves isolation of acetylcholine by high-voltage paper electrophoresis, alkaline hydrolysis of acetylcholine to choline, and conversion of this into [32P]-phosphoryl choline in the presence of choline kinase and [y32P] ATP. The labeled derivative is isolated by column chromatography on Bio-Rad AG1-X8 resin, using Tris buffer solution as the eluent. Cerenkov radiation from 32P is counted (at 33% efficiency) in a liquid scintillation spectrometer. The amount of phosphorylcholine is proportional to the amount of choline over the range of 0.08-8.25 nmol. 

The most often used methods include the 2n a-counting method, 47t P-counting with a 47t gas flow counter, 4jt P-counting with a liquid scintillation spectrometer, and the 471 P-y coincidence counting method. 

For liquid scintillation counting (LSC), a Packard Tri-Carb 460 CD microprocessor controlled liquid scintillation spectrometer, with automatic external standarization, quench correction, and conversion of counts per minute (cpm) into disintegrations per minute (dpm), was utilized. An appropriate scintillation cocktail was selected according to sample characteristics Insta-Gel II (Packard) was used for aqueous solutions and organic extracts, Dimilume-30 (Packard) for NaOH solutions and... 

Chemiluminescence (CL) was measured on all samples Immediately after plasma irradiation and before exposure to air or moisture and again after exposure to room air. CL in counts per min (CPM) was determined in a Packard 3255 liquid scintillation spectrometer equipped with low dark-noise photomultiplier tubes (RCA 4501/V4) and a Parkard 585 linear recorder. 

Idahl, L.-A., SandstrOm, P.-E., Sehlin, J., Measurements of Serum Glucose Using the Luciferin/ Luciferase System and a Liquid Scintillation Spectrometer , AnaL Biochem. 155 (1986) 177-181. 

All tubes contained the following components (in /nmoles unless stated otherwise) potassium phosphate, pH 6.5, 100 ascorbate, 6.0 fumarate, 50 tyramine-/3/3 -3H, 2.0, specific activity 1.15 X 10 CPM//nmole catalase, 300 units, dopamine /3-hydroxylase (4), Final volume, 0.68 ml. at 25°C. Octopamine determined by a minor modification of a published procedure (17). A 0.05 ml. sample of water was obtained by lyophilization and dissolved in 10 ml. of Bray s scintillation mixture. Radioactivity determined in a Packard liquid scintillation spectrometer total counts collected were sufficient to yield a 5% coefficient of variation. The expected tritium release was calculated from the octopamine formed, assuming that the amount of tritium was the same in both /3 positions of the tyramine. The results for the amount of tritium released have been corrected for the amount of exchangeable tritium initially present in the tyramine. 

Thin layer chromatography. Chromatography on Brinkman silica gel plates was conducted with the solvent systems given in the appropriate tables. After development of the chromatogram, the position of C was determined by scraping the silica gel in 2 cm sections into scintillation vials. Scintillation fluid was added and the C was determined in a liquid scintillation spectrometer. 

Takiue, M. and Ishikawa, H. 1978. Thermal neutron reaction cross section measurements for fourteen nuclides with a liquid scintillation spectrometer. Nucl Instrum Methods 148, 157-161. 

The analysis of the radioactivity was performed in a Nuclear Chicago Mark II liquid scintillation spectrometer. 

Packard model 3255 Tricarb and Nuclear Chicago Mark I liquid scintillation spectrometers (LSS) were used for the experiments. 

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