Authors:Amar M. Ait, M. Idbenali, N. Selhaoui, K. Mahdouk, A. Aharoune, and L. Bouirden
available in the literature. In the present parameter optimization procedure, we first imposed the conditions d 2 G /d x 2 for modeling the liquid phase ( 0 L Ru,Y ) using the phase boundary data reported by Massalski [ 6 ] and thermodynamic data determined
Authors:Henryk Piekarski, Katarzyna Łudzik, and Michał Wasiak
concentration (c.m.c.), more pronounced visco-elastic properties, higher capacity to effectively reduce surface tension, etc. are determined by the structure of molecules and has been described in the literature, e.g. [ 3 , 10 ]. The micellisation processes in
Authors:Łukasz Komsta, Urszula Dunin, and Robert Skibiński
During our previous studies, we discovered that reversed-phase thin-layer chromatography (RP-TLC) plates can behave in typical normal-phase manner, which is not widely known nor used in the literature. Therefore, we decided to investigate this behavior more comprehensively on RP-8 plates. We used 35 model compounds, and performed chemometric screening mixture design approach for 20 popular solvents. This gave us the possibility to estimate separate retention effect for each solvent being the measure of average solvent strength. The results were compared to the previous study done on silica gel. It can be concluded that RP-8 plates can be used in typical normal-phase systems and their behavior does not differ substantially from silica gel plates.
Authors:Hariom Nagar, Jürgen Martens, and Ravi Bhushan
Enantioresolution of three active pharmaceutical ingredients (APIs), namely, atenolol, betaxolol, and orciprenaline, marketed as racemic mixture, has been achieved in a direct mode using (S)-glutamic acid as chiral additive in thin-layer chromatography. Two different approaches were adopted: (1) (S)-glutamic acid was mixed in the silica gel slurry for making thin-layer plates, or (2) it was added in the mobile phase and plain plates without any chiral additive were used. Both (1) and (2) were capable of separating enantiomers of all the three racemates, but different combinations and proportions of solvents were found successful in the two cases. Good resolution was achieved in both cases, and the results are compared for these two sets of studies among themselves and with other literature reports. Iodine was used to locate the spots of the corresponding enantiomers. The detection limits for each enantiomer were found in the range of 1.4–1.9 μg (per spot).
, according to the literature, the presence of the θ-Al 2 O 3 phase in these samples suggests a crystallite size smaller than 25 nm [ 12 ]. In the AlCr samples ( Fig. 3c ), the Cr 1.23 Al 0.77 O 3 phase was crystallized at 500 °C and remains stable for
Authors:L. H. Blanco, O. M. Vargas, and A. F. Suárez
decrease with temperature and an increase with concentration, this is due to the nature of the solvent. These observations are in agreement with previous results found in literature [ 9 ].
The molar apparent and molar partial volumes at infinite
Authors:T. Fukumoto, P. S. Thomas, B. H. Stuart, P. Simon, G. Adam, R. Shimmon, and J.-P. Guerbois
solutions were prepared from NaOH pellets (97%, Ajax Finechem, Australia).
Synthesis of DMU
DMU was synthesised according to a method described in the literature [ 13 ]. A sodium phosphate buffer with pH 8 was prepared by
Authors:Miha Vivoda, Robert Roškar, and Vojko Kmetec
development of a suitable method which could be compared to previous literature data [ 14 , 15 ] and nifedipine was chosen as its amorphicity/crystallinity properties are of prime importance for its performance and pharmacological use. The amorphous lactose
Authors:Qasimullah, Ali Mohammad, and Mahfoozurrahman Khan
This review encapsulates the work which appeared in the literature during 1995–2015 on the use of microemulsion as the mobile phase in the analysis of inorganic anions and organic compounds by thin-layer chromatography (TLC). Among anionic, cationic, and non-ionic surfactants used as one of the components of oil-in-water (O/W) and water-in-oil (W/O) microemulsions, sodium dodecyl sulfate (SDS) (anionic surfactant) has been found the most effective for the analysis and separation of different compounds. Compared to the work performed with the use of W/O microemulsion, little work has been reported on use of O/W microemulsion in the TLC—high-performance thin-layer chromatography (HPTLC) analysis of organic compounds. In contrary to TLC, more work has been done on use of O/W microemulsion in high-performance liquid chromatography (HPLC). Out of the sorbent phases, silica gel in combination with microemulsion eluent has been favorable for realizing analytically useful separations. Classification of microemulsions and surfactants is also discussed in the present review.