Authors:K. Heydorn, Z. Alfassi, E. Damsgaard, B. Rietz, and P. Solgaard
In a European study of fish death in mixing zones of rivers with different acidities a reliable determination of Al and other elements in gills from freshwater fish was required, and both INAA and ICP-MS were studied as candidate reference methods. INAA requires minimum sample handling with a correspondingly small risk of contamination and no blank value; however, a careful study was needed of both nuclear interference from P and the increased detection limit caused by other major elements in the sample, before reliable results for Al could be ascertained. ICP-MS requires dissolution of the sample with a resulting risk of contamination and a significant reagent blank; while sensitivity was good, the interference from N created problems for sample decomposition in the microwave oven. Our experience with actual samples indicates that both methods suffer from considerable contamination problems, requiring that samples be handled in a clean bench with superpure reagents. Nuclear interference was determined experimentally by irradiating stoichiometric P-compounds with and without a Cd-shield; the observed interference of 1 g Al from 50 mg of P was found to require no correction in almost all cases. The accuracy of results was ascertained by analyzing SRM 1577 Bovine Liver.
Authors:Iskra Boneva, Spaska Yaneva, and Dancho Danalev
A method for simultaneous determination of trace of four organophosphorus pesticides residues in animal liver samples has been developed and validated. This method is based on the preliminary sample preparation using extraction of target compound with a mixture of toluene-cyclohexane by means of up-to-date accelerated solvent extraction (ASE), liquid-liquid partitioning with acetonitrile and hexane, additional clean up step using QuEChERS method. Further the obtained analytes are determined by gas chromatography with ion-trap detector. The validation of the method is performed in accordance with the recommendations in Document SANTE/11945/2015 and it meets the acceptability criteria for precision, mean recovery and limits of quantification. The samples were investigated by analysing blank liver samples and samples spiked with the target analytes chlorpyrifos-methyl, parathion and pirimiphos-methyl at levels of 25, 50, and 75 ng/g and with diazinon at levels of 15, 30, and 45 ng/g. The recovery for all compounds were in the range from 73 to 104% which perfectly fit with requirements of documents and European legislations. The repeatability and within-laboratory reproducibility also reveal acceptable in documents coefficient of variation and uncertainty less than 20 and 18%, respectively. The limits of quantification were less than 3 ng/g for all compounds and allowed determination of residues below the maximum residue levels (MRLs) set in Regulation (EC) Nº 396/2005.
Thermal analysis methods are well-established techniques in research laboratories of pharmaceutical industry. The robustness
and sensitivity of instrumentation, the introduction of automation and of reliable software according to the industrial needs
widened considerably the areas of applications in the last decade. Calibration of instruments and validation of results follow
the state of the art of cGMP as for other analytical techniques. Thermal analysis techniques are especially useful for the
study of the behavior of the poly-phasic systems drug substances and excipients and find a unique place for new delivery systems.
Since change of temperature and moisture occur by processing and storage, changes of the solid state may have a considerable
effect on activity, toxicity and stability of compounds. Current requirements of the International Conference of Harmonisation
for the characterization and the quantitation of polymorphism in new entities re-enforce the position of thermal analysis
techniques. This challenging task needs the use of complementary methods. Combined techniques and microcalorimetry demonstrate
their advantages. This article reviews the current use of thermal analysis and combined techniques in research and development
and in production. The advantage of commercially coupled techniques to thermogravimetry is emphasized with some examples.
Authors:Elise Ivarsen, Christoffer P. Andersen, Sabine M. Jensen, Carsten T. Pedersen, and Anders K. Svaneborg
This study presents the optimization and validation of methods for the analysis of retinol, thiamine, niacin, pyridoxine, folic acid, cyanocobalamin, zinc, and iron in fortified kernels (coated and extruded) and in fortified rice. The analyses were performed by HPLC-UV/FLD/MS and ICP-OES. The optimized methods showed good resolution of the analyte peaks, excellent recovery (87–108%), reproducibility with relative standard deviation (SD) of analyte content between 1.8 and 11% and high correlation coefficient of the calibration curves (R2 > 0.997). Limit of detection was from 2.8 E-4 mg/kg for pyridoxine to 1.26 mg/kg for zinc and limit of quantification was from 9.2 E-4 mg/kg for pyridoxine to 4.21 mg/kg for zinc. Thereby the optimized methods demonstrated reliability and sensitivity in the detection and quantification of these micronutrients and that they are suitable for routine analysis of fortified kernels (coated and extruded) and fortified rice.
A new validated high-performance thin-layer chromatographic (HPTLC) method has been developed for the simultaneous determination of anti-inflammatory compounds betulinic acid (BA, 1), 24β-ethylcholesta-5,22E,25-triene-3β-ol (ECTO, 2), and lupeol (LU, 3) in the roots of Clerodendrum phlomidis. Extraction efficiency of marker compounds was studied using normal (cold and hot), ultrasonic, as well as microwave-assisted extraction techniques with various solvents. Well-resolved separation of marker compounds was achieved on silica gel 60F254 plates using the mobile phase consisting of chloroform-methanol (98:2, ½/½). Marker compounds were scanned using the densitometric reflection-absorption mode after post-chromatographic derivatization with vanillin-sulfuric acid reagent. Validation of method was performed as per the International Conference on Harmonization (ICH) guidelines. Report on the occurrence of betulinic acid for the first time in C. phlomidis is of chemotaxonomic importance. In addition, anti-inflammatory potential of the rare sterol ECTO (2) on lipopolysaccharide (LPS)-stimulated production of pro-inflammatory cytokines (tumor necrosis factor-α [TNF-α] and interleukin-6 [IL-6]) was also evaluated as it was not reported earlier.
Authors:S. Chhillar, R. Acharya, S. Sodaye, K. Sudarshan, S. Santra, R. Mishra, C. Kaushik, R. Choudhury, and P. Pujari
Barium borosilicate glass (BaBSG) is proposed as a potential candidate for vitrification of nuclear waste generated from thoria
based nuclear reactors. Along with fission products, activation products and many inactive chemicals, like fluorine in the
form of HF are expected to be present in the dissolver solution with nuclear waste. As vitrification occurs at high temperature,
it is important to quantify fluorine in BaBSG. Due to its complex matrix, most of the wet chemical and nuclear analytical
methods encounter problems in the estimation of fluorine. Particle induced γ-ray emission (PIGE) method has been standardized
for non-destructive determination of fluorine contents in BaBSG samples utilizing measurement of prompt gamma-rays from 19F (p, p’γ) 19F reaction. Experiments have been carried out with thick pellet targets prepared in cellulose matrix using 4 MeV proton beam
from the folded tandem ion accelerator at BARC, Mumbai. For obtaining current normalized count rate of interest, beam current
variation was monitored by the Rutherford backscattering spectrometry (RBS) method as well as by the in situ approach using
an externally added element sensitive to PIGE. In this paper standardization of PIGE methods for F determination, validation
of methods using synthetic samples, and application to BaBSG samples are reported.
guidelines for single-laboratory validationofmethods of analysis (IUPAC Technical Report), Pure Appl. Chem. 74 (2002) 835–855.
Harmonized guidelines for single-laboratory validationofmethods of analysis (IUPAC Technical Report