Authors:M.A. Hawrył, M. Niemiec, K. Słomka, M. Waksmundzka-Hajnos, and G. Szymczak
Micro-thin-layer chromatography in two dimensional (2D-mTLC) mode in normal and reversed phase systems by use of diol bonded stationary phase was applied to make fingerprints of 11 species of Mentha genus and two finished pharmaceutical products.
Nonaqueous eluents (propan-2-ol or ethyl acetate dissolved in n-heptane) were used in normal phase systems. Mixtures of acetonitrile with water were used in reversed phase chromatographic systems.
Optimization of one dimensional systems was performed by determining of RF vs. composition of mobile phases dependencies for standards occurring in various species of Mentha. Most selective eluents were chosen to optimize two-dimensional systems by creating RF in normal-phase (NP) systems vs. RF in reversed-phase (RP) systems correlations.
2D-mTLC on diol polar bonded stationary phase were optimized to separate phenolic compounds and make fingerprints of examined plant materials and this method was never applied earlier in the chromatographic analysis.
-molecular-mass glycol or diol which serve as glycolysis agents. Usually, the catalysts are used, and in some cases, amines are added which results in aminoglycolysis. The products of glycolysis are the so-called glycolysates, which consist of a homogenous mix of various
– 14] . Methanol solutions in some respects show similar properties to those of aqueous solutions and in others they resemble DMF solutions. Recently, we have turned our attention to systems containing a diol as a non-electrolyte. The wide applications
different sizes (from 3–4 to 15°μm).
The main products of the process of allylic compound epoxidation are epoxide compounds. Depending on the conditions, the following compounds are also formed: diols—the products of epoxide ring hydration, ethers
Authors:E. Keppelné Bognár, K. Zay, and L. Somogyi
fatty acid esters in edible oils and fats (in this study we examined only 3-MCPD-FE). The method is based on alkaline-catalyzed ester cleavage, and derivatisation of free diols with PBA. These derivatives were measured in splitless mode by GC/MS coupled
Authors:Bao-xia Fang, Lin-hai Wang, Fu-chao Chen, Peng Li, and Xiao-ya Shi
Butorphanol tartrate ( Figure 1 a) is a mixed agonist–antagonist opioid with strong κ-receptor agonist and weak μ-receptor antagonist activity. Chemically, it is morphinan-3,14-diol,17-(cyclobutylmethyl
Authors:Jerzy J. Chruściel, Grażyna Janowska, and Marzena Fejdyś
successfully used as halogen-free fire retardants. Ammonium polyphosphate, microencapsulated with a low molecular weight polydimethylsiloxane-α,ω-diol, showed enhanced water resistance and significantly improved flame resistance properties as compared with an
with no maxima [ 15 ]. 1,2-diols as cosolvents behave similarly in the range of high methanol content [ 16 ]. The absence of the maxima of the Δ sol H ° in these mixtures within the methanol-rich range seems to point to the lack of ordering structure
HILIC system. Preliminary tests were performed on several different HILIC columns: silica, cyano, amino and diol. The amino column was selected as the most suitable stationary phase for further analysis. In preliminary studies, acetonitrile was selected