PubMed · 3809907
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K Cwiek. 1986. [Determining BHT migration from paper/polyethylene laminates].. https://pubmed.ncbi.nlm.nih.gov/3809907/
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HPLC methods were developed and validated for potential extractables [zinc dithiocarbamate, 2,6-di-tert-butyl-para-cresol (BHT), octylated diphenylamine antioxidant, sulfur, pentylphenol, and tetrakis(methylene(3,5-di-tert-butyl-4-hydroxyhydro cinnamate))methane] from commercial elastomeric stoppers in a complex surfactant matrix. These stoppers were proposed to be part of the container-closure system for experimental formulations containing the surfactant, polyoxyethylated Castor oil (USP/NF) (POE Castor oil) and ethanol. The presence of POE Castor oil in the formulation posed unique challenges to the development and validation of the HPLC methods. POE Castor oil, also known as Cremophor, is a viscous and complex solubilizing agent with a number of uncharacterized fractions. Hence the goal was to identify HPLC conditions that would be suitable for the separation, detection, and quantitation of the potential stopper extractables in the presence of such a complex drug product matrix. A number of experiments were performed to evaluate the effects of different columns, mobile phase composition, injection volume, and gradient profile on the separation and detection of the potential stopper extractables. The quantitation limits of these stopper extractables are between 1 and 10 ppm. The methods demonstrate good linearity, acceptable accuracy, and precision.
The present study for the first time describes the application of matrix-assisted laser desorption ionisation time-of-flight mass spectrometry (MALDI-ToF MS) to palynology. With an accessible mass range of up to about 350,000 Da at subpicomolar range, this technique is ideal for the characterisation of bio-macromolecules, such as sporopollenin, found in fossil and extant pollen and spore walls, which often can only be isolated in very small quantities. At this stage, the limited solubility of sporopollenin allows for the identification of sections of this biopolymer, but with the optimisation of MALDI-ToF matrices, further structure elucidation will become possible. Furthermore, gas chromatography-mass spectrometry (GC-MS) and (1)H nuclear magnetic resonance ((1)H NMR) spectroscopy data obtained from a number of experiments revealed that some previously reported data were misinterpreted. These results add support to the hypothesis that common plasticizers were wrongly described as sporopollenin compounds.
In a culture experiment, the effects of different concentration 2,6-bis (1, 1-dimethylethyl) phenol and 1,2-benzodicarboxylic dimethyl ester on the photosynthesis and chlorophyll fluorescence characteristics of eggplant seedlings were studied, and the results showed that these two allelochemicals were the barriers of chlorophyll content, net photosynthetic rate (Pn), and stomatal conductance (Gs). The intercellular CO2 concentration (Ci) decreased in the former period, and then increased. The allelochemicals increased initial fluorescence (Fo), but decreased maximum photochemical efficiency of PS II (Fv/Fm), quantum efficiency of non-cyclic electron transport of PS II (phi(PSII)), photochemical quenching ((qP) and antenna conversion efficiency (Fv'/Fm' ). 2,6-bis (1,1-dimethylethyl) phenol made non-photochemical quenching (qN) increase first and decrease then, while 1,2-benzodicarboxylic dimethyl ester decreased qN, which was harmful to the photosynthesis structure.