Optimized Separation Method for Estriol, 17-β-Estradiol and Progesterone by Capillary Electrochromatography with Monolithic Column and its Application to a Transdermal Emulsion

<div><p>A monolithic stationary phase based on 3-(methacryloxypropyl)trimethoxysilane monomer, prepared within a fused silica capillary externally coated with a UV-transparent fluoropolymer was employed for separation of estriol, 17-b-estradiol and progesterone by capillary electrochromatography in a standard mixture. A 23 factorial design was used to optimize the separation system. The optimized condition containing 30% (v/v) of acetonitrile and 10 mmol L-1 aqueous ammonium acetate presented a total run time less than 10 min by applying 25 kV. The resolution between adjacent peaks ranged from 1.8 up to 2.9 and the plate numbers per column meter in this condition was 1873, 3631 and 3886 for the estriol, 17-b-estradiol and progesterone peaks, respectively. The optimized method was employed in the quantitative analysis of a commercial transdermal emulsion formulation.</p></div

Comparative Study of the Lipid Profiles of Oils from Kernels of Peanut, Babassu, Coconut, Castor and Grape by GC-FID and Raman Spectroscopy

<div><p>The characterization of the lipid profiles of oils extracted from the kernel of seeds and nuts of peanut (Arachis hypogaea), babassu (Attalea speciosa), coconut (Cocos nucifera), castor (Ricinus communis) and grape (Vitis vinifera) was performed by using Raman spectroscopy and gas chromatography with flame ionization detector (GC-FID). Chromatographic analyses showed that coconut and babassu oils are composed essentially by saturated fatty acids (SFA), whereas the others are composed mainly by unsaturated fatty acids (UFA). The comparison of commercial and homemade castor oils showed the former have a lower level of ricinoleic acid at ca. 58%. Spectroscopic analyses of three distinct castor oils showed their profiles could be differentiated by marker features ascribed to carbonyl modes which were correlated with storage time. The comparison between the Raman spectra of standard samples of fatty acids with the samples of oils allowed the assignment of the spectroscopic features and the characterization of marker bands for the degree of unsaturation.</p></div

Alkaline Solubilization of Chicken Tissues Monitored by Raman Spectroscopy Followed by Pb Determination by GF AAS

<div><p>This paper proposes a method for chicken tissues preparation using tetramethylammonium hydroxide (TMAH) for Pb determination by graphite furnace atomic absorption spectrometry employing multivariate approaches. Combining Raman spectroscopy with scanning electron microscopy coupled to energy-dispersive X-ray spectroscopy to monitor the solubilization process it was possible to show that TMAH acts in the solubilization of proteins, amino acids and lipids. Besides, this investigation showed that the small residual masses of samples have organic and inorganic compounds. Accuracy tests indicated that such residues have not interfered in the analytical results (recovery between 90-95%). The obtained limits of detection (0.099 µg g -1) and quantification (0.33 µg g -1) are compatible with the detectability required for regulatory purposes. Linearity (R2 = 0.9925) and characteristic mass (13 pg) were also reported. Considering the set of 15 samples comercialized in Brazil, any Pb contamination was successfully observed and this was confirmed by the analysis of digested samples.</p></div

New 9-Aminoacridine Derivative: Synthesis, Study and Potential Application as pH Indicator in Organic Solvents

<div><p>In this work, we describe the synthesis of a novel 9-aminoacridine derivative that presents surprisingly different colors when exposed to neutral, acidic or basic mediums with potential application as pH indicator in organic solvents. Furthermore, pKa and molar absorptivity values were determined and theoretical studies supported by density functional theory (DFT) calculations were performed to elucidate the different structures of this compound.</p></div