A rapid radiochemical procedure for indium

A rapid radiochcmical procedure was developed for the separation of indium radionuclides from a mixed fission-product solution. An alcoholic pyridine solution is added to a uranium solution containing indium and tin carriers. The resulting tin precipitate is separated from the indium-containing solution by filtering through a cellulose membrane filter. The decontamination factor for tin is 2·10³. Other fission products are only partially removed. The chemical yield of indium is about 44%, and the time required for the separation is about 10 sec. After the tin-separated indium has decayed, the tin daughters of indium are removed from all the other fission products at a specified time and measured, so that the amount of indium present at the time of the tin precipitation is determined.     

A rapid iodine radiochemical procedure

A radiochemical procedure was developed to determine fission yields and radiation characteristics of short-lived iodine fission products.Iodine was separated from other fission products of uranium in less than 10 sec after completion of irradiation. High decontamination factors of iodine from Sn, Sb, Te, Xe, Cs and Ba, and high chemical yields were obtained. The sample was prepared by dissolving uranium peroxide in molten periodic acid; the melt was cooled, ground and mixed with activated carbon. After irradiation, the periodic acid was decomposed by heat and the gaseous iodine formed was collected in carbon tetrachloride or in a cooled counting chamber. Higher temperatures could be used than in conventional aqueous systems, thus enhancing the exchange of carrier and fission product iodine.     

A rapid magnetizable solid phase radioimmunoassay kit for human placental lactogen

The radioimmunoessay of human placental lactogen (HPL) with separation of antibody bound and free hormone was achieved by the magnetizable solid phase coupled to antibody. The precision, accuracy, sensitivity and specificity of the method has been carefully checked in this study and the procedure of the assay was performed at room temperature. The above parameters were evaluated by recovery test (99%); within assays (4%), between assays (5%), sensitivity (0.04 g/ml) and there was no obvious cross reactivity with human growth hormone (hGH) and human chorionic gonadotropin (hCG).     

A rapid and simple cleanup procedure for metathesis reactions

[structure: see text]. A new method for easy removal of ruthenium from metathesis reactions by using a polar isocyanide is reported. This protocol removed most ruthenium byproducts from a variety of synthetically useful metatheses. Moreover, the isocyanide-promoted carbene insertion results in rapid destruction of carbene reactivity, demonstrated in the commonly used first- and second-generation Grubbs' carbenes.     

A rapid radiochemical procedure for uranium determination in natural waters

A neutron activation analysis method for the determination of uranium in natural fresh waters is described. The method is based on a preconcentration step by precipitation of the metal oxinate on a phenolphtalein bed followed by instrumental neutron activation analysis. Preliminary investigations with²³⁹U radiotracer were carried cut to set up the best working conditions and to evaluate the chemical yield. The whole procedure has been applied to the determination of uranium in river water.     

A rapid and high-yield aqueous phase preparation procedure for123I-labelled meta-iodobenzylguanidine

A new, aqueous phase preparation procedure for¹²³I-mIBG /meta-iodobenzylguanidine/ is described. It comprises a copper-catalyzed exchange reaction between aqueous¹²³I-iodide and mIBG at 150 °C for 45 min, a purification via anion-exchange chromatography, and a sterilization via micropore filtration. Overall preparative yield, radiochemical purity and specific activity amount to >90%, >99.7% and >10¹⁵ Bq.mol^–1 mIBG, respectively. Other features are simplicity /no evaporation of water or other solvents/, reproducibility of labelling yield and radiochemical purity, and speed /total time required 1.5 h/.     

A radioimmunoassay for serum estradiol

A radioimmunoassay procedure to measure estradiol levels in human serum was developed using¹²⁵I labeled estradiol and antiestradiol antibody raised in-house using the estradiol-6-CMO-BSA as the immunogen. Controlled process serum was used to maintain the serum matrix and sample-standard identity. The assay was validated by analysing several (n=40) samples and comparing with established commercial assays. The assay had a sensitivity of 35 pg/mL and a range of 50 pg/mL to 5 ng/mL. The interassay C.V. were between 2 to 10% while the intraassay C.V. were between 2 and 8%. This assay is sensitive enough for monitoring ovulation and hypersecretions in ovarian tumours and was primarily developed to be used as an in-house assay in the local hospitals.     

A rapid chemical separation procedure for the determination of burn-up of nuclear fuel

A chemical separation procedure for the determination of burn-up is described. The isolation of uranium, plutonium and neodymium is based on two ion-exchange separations, the first one an anion exchange in hydrochloric acid—nitric acid medium and the second one a cation exchange under high pressure with α-hydroxyisobutyric acid. Several experimental facts like chemical yields, contaminations and cross contaminations are discussed.     

A rapid isotope dilution inductively coupled plasma mass spectrometry procedure for uranium bioassay

Negative health effects of uranium taken into the human body are related to both the chemical toxicity of the metal and its radioactivity. A simple and reliable isotope dilution ICP-MS uranium bioassay technique was developed in this study. Use of this technique at Los Alamos National Laboratory has not been previously described. Dilute urine was introduced to a Perkin Elmer DRC II quadrupole ICP-MS via a PFA high solids nebulizer and a PFA cyclonic spray chamber cooled to 2 °C. Urine samples acidified, digested, and diluted 5× generate a solution that is roughly 10% HNO₃ that can be analyzed by ICP-MS to measure uranium concentrations >54 pg/mL and uranium isotopic ratios with high enough precision and accuracy to determine if the uranium in a urine sample is natural. A three-stage rinsing routine is run between each sample to minimize urine salt deposition and uranium memory effects. Regular use of this rinsing routine minimizes instrumental drift and has produced a running ²³⁸U background of <7 cps.     

A rapid procedure for the determination of the tellurium content of organotellurium compounds

A rapid micro-analytical procedure for the analysis of tellurium in organotellurium compounds is described. The compounds are decomposed using the conventional oxygen flask method followed by treatment with aqueous hydrogen peroxide/hydrochloric acid solution. The tellurium content of the resulting solution is determined by atomic absorption spectrophotometry. If the analyses are carried out batch wise i.e. 6–8 samples with each standardisation of the instrument, the total analysis time is about $\text{1}\text{2}$ hour per sample.     

A novel procedure for rapid surface functionalisation and mediator loading of screen-printed carbon electrodes

We report a simple and rapid procedure that leads to incorporation of mediator and introduction of amine functionality onto the surface of screen-printed carbon electrodes (SPCE). The electrodes were doped with cobalt phthalocyanine (CoPc) by enhanced adsorption in a process that uses minimal amounts of this redox mediator as compared with CoPc loaded inks. The CoPc-doped SPCE showed a substantially increased sensitivity to hydrogen peroxide and thiocholine as compared to unmodified electrodes. This greatly facilitated their use as transducers for the construction of amperometric biosensors based on enzymes producing oxidizable products such as hydrogen peroxide or thiols. Immobilisation of enzymes including glucose oxidase, acetylcholinesterase and choline oxidase was achieved through their multi-contact electrostatic interaction with polyethyleneimine (PEI) which was electrodeposited on the surface of CoPc-doped electrodes in one step from ethanolic solution. The efficiency of enzyme immobilisation was shown to depend on the molecular weight of the PEI used, reaching a maximum for 25 kDa PEI. The biosensors shown sensitivity to glucose at 130 nA mM⁻¹ (LOD 0.15 mM) and to acetylcholine at 70 nA mM⁻¹ (LOD 0.10 mM) under +0.6 V. Detection of glucose has been demonstrated at +0.4 V with the sensitivity of 60 nA mM⁻¹ and LOD of 0.33 mM. Possibility of the inhibition analysis of pesticides has been shown for acetylcholinesterase-based sensors.     

A sequential injection fluorometric procedure for rapid determination of total protein in human serum

A sensitive procedure for the quantification of total protein bovine serum albumen (BSA) in human serum was presented with sequential injection sampling and fluorometric detection. A few microliters of sample and fluorescamine solutions were aspirated into the holding coil to facilitate the reaction of protein with fluorescamine by giving rise to a blue-green-fluorescent derivative. The derivative was afterwards excited by a 400 nm radiation from a UV radiator, and the emitted fluorescence was monitored at the wavelength of 470 nm. By loading 5.0 μl of sample and 4.0 μl of fluorescamine solution 0.075% (m/v), a linear calibration graph was obtained within 0.3-12.5 μg ml⁻¹, and a detection limit (3σ) of 0.1 μg ml⁻¹ was achieved, along with a sampling frequency of 40 h⁻¹ and a R.S.D. value of 2.1% at the 5.0 μg ml⁻¹ levels. Protein contents in human serums were analyzed by using the present procedure, and reasonable agreements were obtained with those obtained by a documented spectrophotometric (Biuret) method.