Simple and rapid determination of phosphorus in meat samples by WD-XRF method

The wavelength dispersive X-ray fluorescence (WD-XRF) method for phosphorus determination in meat samples has been described. The effects of sample pretreatment on the XRF analysis have been discussed. The phosphorus content determined in meat samples ranged from 603 ± 6 to 613 ± 19 mg P/100g dry mass (d.m.), depending on the sample preparation technique. The meat samples spiked with phosphates have been used for the calibration procedure. The accuracy was determined against a number of certified reference materials (SMRD 2000, RF 8414, NIST-1568A, and NIST-1549), and recovery was assayed using the standard addition procedure. The proposed method has been compared with the standard spectrophotometric method (PN-ISO 13730, 1999) of total phosphorus determination. The sample pretreatment procedure has been reduced to minimum the presented results suggest the WD-XRF method can be an alternative to the spectrophotometric analysis.     

A Mild Procedure for the Stereospecific Transformation of trans Cinnamic Acid Derivatives to cis β-Bromostyrenes

A new mild procedure has been developed for the synthesis of cis β-bromostyrene analogs with complete Z/E selectivity and good to excellent yields (58.4 - 90.9%). The process involves carboxyl-halo-elimination of cinnamic acid dibromides by using triethylamine in N,N-dimethylformamide at room temperature. A one-pot procedure has also been described for the direct transformation of cinnamic acids to β-bromostyrenes.     

Application of pyrolysis—gas chromatoghaphy in the analysis of diad sequence distribution in styrene—glycidyl methacrylate copolymers

A procedure has been suggested for the characterization of the distribution of diad sequences for copolymers of the vinyl type prepared to high degrees of conversation pyrolysis—gas chromatography. The procedure has been verified for styrene—glycidyl methacrylate copolymers.     

Iron(0) nanoparticles mediated direct conversion of aryl/heteroaryl amines to chalcogenides via in situ diazotization

A simple procedure for the synthesis of organo-chalcogenides has been developed by the reaction of aryl/heteroaryl amines with di-aryl/heteroaryl dichalcogenides in the presence of ^tBuONO and Fe(0) nanoparticles. The reaction proceeds via in situ diazotization followed by chalcogenation. A series of functionalized diaryl/aryl heteroaryl/diheteroaryl/aryl-alkyl selenides, sulfides and tellurides have been obtained by this procedure. Significantly, using this procedure 2,4-dinitroaniline is converted to (2,4-dinitrophenyl)(phenyl)selane which is known as thioredoxin reductase (TR) and glutathione reductase (GR) inhibitor. The reaction goes by a radical pathway and a plausible mechanism has been suggested.     

Determination of237Np in large volume samples of sea water by a radiochemical procedure

A radiochemical procedure followed by alpha spectrometry has been developed for the determination of²³⁷Np present at low activity concentrations in seawater. The analytical procedure is based on concentration of actinides from 1800 1 sea water samples by hydroxide precipitations. Neptunium is isolated by ion exchange, fluoride precipitation and extraction with TTA (thenoyltrifluoroacetone). As a radiochemical yield determinant²³⁹Np or²³⁵Np is used. Neptunium is electroplated onto stainless steel discs before alpha-spectrometry for about 10 days. The procedure allows for sequential separation of plutonium, americium, technetium and radiocaesium together with neptunium. The radiochemical yield for neptunium is only 20–50%, but the procedure has been applied with success on several samples contaminated with²³⁷Np at fallout or close to fallout levels.     

Configuration interaction study of H2 and H3 systems

The configuration interaction method has been applied to the H₂ and H₃ systems. The effect of increasing the size of the atomic Slater-type orbital basis has been studied. A minimization procedure with respect to orbital exponents has been carried out.     

Radioimmunoassay of human placental lactogen

A sensitive and specific radioimmunossay procedure (RIA) has been developed for the measurement of Human Placental Lactogen (HPL). Pure HPL has been labelled with¹²⁵I and a specific activity of 100 μCi/μgm of HPL has been attained. Dextran-coated charcoal has been employed to separate the bound from the free hormone in radioimmuno-assay. The sensitivity of this technique has been found to be 0.2 ng of HPL. Intraassay and inter assay variations have been found to be less than 10%. This procedure has been adopted to establish the normal range of HPL in pregnant women at different periods of gestation, and to evaluate risk pregnancies.     

A sorption-catalytic procedure for determining histamine

It has been found that histamine acts as an inhibitor in the reaction of hydroquinone peroxidation catalyzed by Cu(II), when it is carried out in a solution, and as an activator, when this reaction is carried out on paper carriers. A supposition on the reasons for the inhibiting and activating effects has been made on the basis of the theory of the intermediate active complex. A procedure for the determination of (3−9) × 10⁻¹³ M histamine using copper-containing paper filters with chemically attached hexamethylenediamine groups has been developed. The strongest interference with the determination of histamine is observed for diethylamine and triethylamine. The procedure has been used for the sorption-catalytic determination of histamine in human saliva at the nM level.     

Further studies in the advance prediction of gamma-ray spectra and detection limits in instrumental neutron activation analysis

This computational procedure, described earlier for NaI(Tl) gamma-ray spectrometry, has now been set up for Ge(Li) spectrometry measurements, has been extended further in various details, has been partially computerized, and has been tested experimentally on both biological and geochemical types of samples—with good results. The procedure enables one to compute, in advance of any activations, the approximate Ge(Li) pulse-height spectrum of a sample for any selected flux and irradiation, decay, and counting times —and to compute the lower limits of instrumental NAA detection of any trace elements of interest—if the principal composition of the matrix is known. Various other useful parameters are also readily calculated.     

SILICA GEL SUPPORTED JONES REAGENT (SJR): A SIMPLE,VERSATILE, AND EFFICIENT REAGENT FOR OXIDATION OF ALCOHOLS IN NON-AQUEOUS MEDIA

Oxidation of alcohols to carbonyl compounds has been carried out by utilization of Jones reagent supported on silica gel (SJR). The SJR procedure has advantages over traditional Jones oxidation procedure. This procedure is safer to carry out and simplified workup by allowing organic media.     

Determination of the ZnGeP2 composition by inductively coupled plasma atomic emission spectrometry

A procedure employing inductively coupled plasma atomic emission spectroscopy has been developed for the precise determination of the composition of Zn_{1 + x}Ge_{1 + x}P_{2 + x} alloys after their autoclave digestion. An optimal composition of the acid mixture has been chosen and the conditions preventing element losses in the digestion process have been found. To minimize the error of the developed procedure, the optimal concentration of Zn, Ge, and P in the analytes was found by calculating the results of analysis as atomic ratios Zn : Ge and P : Ge. The accuracy of the developed procedure was confirmed by the standard addition method and the comparison of the results with the results of an independent method. The relative standard deviation of the determination of atomic ratios was 0. 7–2.0%.     

Separation of Bufotalin and Cinobufotalin by Preparative Liquid Chromatography

Abstract

Complete resolution of bufadienolides by traditional column chromatography, or by thin-layer chromatography (TLC), is quite difficult. Separation of various bufadienolide conjugates by high performance liquid chromatography (HPLC) has been described, but not for resolution of the corresponding genins. A preparative HPLC procedure has been developed for resolving the difficultly separable bufotalin (1) and cinobufotalin (2). A Lobar B column packed with LiChromprep Si-60 was used to separate these bufadienolides employing a recycling procedure.     

Preparation of pickering-emulsion-based capsules with shells composed of titanium dioxide nanoparticles and polyelectrolyte layers

A procedure has been proposed for the preparation of capsules with shells composed of titanium dioxide nanoparticles and polymers via the formation of Pickering emulsions (colloidosomes) followed by layer-by-layer deposition of polyelectrolytes. The feasibility of stabilizing oil droplets of emulsions by spontaneous adsorption of partly hydrophobized nanoparticles of anatase-form titanium dioxide at the oil/water interface has been studied. Conditions have been determined for the formation of stable colloidosomes and the subsequent layer-by-layer deposition of oppositely charged polyelectrolytes onto their surfaces. It has been shown that hydrophobic dyes may be encapsulated using the procedure developed for the preparation of the capsules. The photocatalytic activity of TiO₂ particles occurring in the shell has been demonstrated by the example of degradation of Nile red which is incorporated in the oil core of a capsule.     

Capillary electrophoresis—matrix-assisted laser-desorption ionization mass spectrometry of proteins

An “off-line” combination of capillary electrophoresis (CE) with matrix-assisted laser-desorption mass spectrometry (MALDI-MS) has been developed for the structural characterization of CE-separated peptides and proteins. Using a sheath flow interface, similar to that developed for “on-line” CE—fast atom bombardment MS and CE—electrospray MS, an efficient sample isolation procedure has been developed which is applicable to bioorganic compounds in aqueous buffer solutions. This isolation procedure, with subsequent transfer to the MALDI-MS sample target, has been successfully used for the direct analysis of CE-separated proteins of M _r up to 67 000, and a mixture of apolipoprotein AII monomer and homodimer, using sample amounts of less than 1 pmol.     

High Performance Liquid Chromatographic Procedure for Retinoic Acid in Ophthalmic Solution

Abstract

A fast and simple procedure has been developed for the quantitation of retinoic acid in ophthalmic solutions. the procedure involves the use of reverse phase high performance liquid chromatography with a mobile phase containing an amine modifier. This procedure is specific for retinoic acid in the presence of its degradation products and formulation excipients. the method is linear over a wide range of concentrations.     

A rapid microdetermination of chlorine dioxide in the presence of active chlorine compounds

A titrimetric and spectrophotometric procedure has been developed for the determination of ClO₂ in water samples. The procedure is rapid, accurate, and free of normal interferences present in water. It is based upon the reaction of ClO₂ with substituted halophenol indicators.     

Determination of Ultra-Trace Amouris of Uranium by Icp-Aes Technique

Abstract

An Atomic Emission Spectrometric method based on the use of Inductively coupled argon Plasma source has been developed for the determination of ultra trace concentrations of uranium in aqueous solutions. Using the optimised experimental conditions for the ICP source, uranium can be determined at 0.05 μg/ml concentration in 0.3M HNO₃ solutions with either of the two analytical lines viz. 3859.6 Å or 4090.1 Å. The precision of determinations at the lowest detection limit is better than 2% R.S.D. The uranium estimation has been corrected for the interference due to the presence of eighteen metallic elements using an inter-element correction procedure. A number of spiked samples and NBL reference samples with concomitant impurities have been analysed using the standardised procedure and good agreement has been observed with their certified values.     

Comparative study of optimised BCR sequential extraction scheme and acid leaching of elements in the certified reference material NIST 2711

The optimised BCR sequential extraction procedure and a 4 h 1 mol L⁻¹ HCl partial extraction have been performed on the NIST 2711 reference material for a suite of 12 elements (Cd, Sb, Pb, Al, Cr, Mn, Fe, Co, Ni, Cu, Zn, As) using magnetic sector ICP-MS. A pseudo-total aqua regia digest of NIST 2711 has also been undertaken for quality assurance purposes, and comparison of the sum of the four BCR fractions, which included an aqua regia digest on the residue, with the pseudo-total aqua regia digest has been used to assess the accuracy of the BCR partitioning approach. As a result of this work, discrepancies between previous studies about BCR partitioning of elements in NIST 2711 have been discussed and an increase in confidence about the use of BCR partitioning scheme on seven elements (Cd, Pb, Al, Mn, Fe, Cu, Zn) in this standard material has been obtained. On the other hand, BCR partitioning for Sb, Cr, Co, Ni and As has been provided for the first time. Partial extraction results are also reported for the same 12 elements analysed by the optimised BCR procedure, with the partial extraction results exhibiting a strong correlation with the sum of the three labile steps of the BCR procedure.     

A facile,catalyst-free synthesis of new polycyclic pyrrolo[1,2-b]pyrazolone derivatives

A convenient and efficient procedure has been developed for the synthesis of a new ring system, pyrrolo[1,2-b]pyrazolone, via two-component coupling reaction followed by base mediated intramolecular cyclization. Single-pot synthesis replacing the two step process has also been successfully carried out. A series of polycyclic pyrrolo[1,2-b]pyrazolone derivatives have been obtained by employing the procedure along with some fused pyrrol-1-ylamine system. The products were formed very rapidly in catalyst free condition in a good yield (up to 75%) and also it had tolerance to a wide scope of substrates.     

Neutron activation and mass spectrometric measurement of129I

An integrated procedure has been developed for measurement of¹²⁹I by neutron activation analysis and mass spectrometry. An iodine isolation procedure previously used for neutron activation has been modified to provide separated iodine suitable for mass spectrometric measurement as well. Agreement between both methods has been achieved within error limits. The measurement limit by each method is about 10⁷ atoms /2 fg/ of¹²⁹I.Operated for the U.S. Department of Energy by Battelle Memorial Institute under contract DE-AC06-76RL0 1830.