Solvent Extraction of Thorium Using 5,11,17,23-Tetra[(2-ethyl acetoethoxyphenyl)(azo)phenyl]calix[4]arene

A rapid, sensitive, and selective method for determination of thorium based on the complex withortho-ester tetra-azophenylcalix[4]arene (TEAC) was described. In the presence of pH of 4–6, TEAC-Th(IV) complex is extracted from an acidic aqueous solution into chloroform layer. The absorbance intensity of complex was measured by UV-Vis spectrometer at 525 nm and the molar absorptivity was found to be 2.4 × 104. Beer’s law was obeyed in the range of 1.0 to 25 × 10−5 M thorium(IV). The effects of pH, TEAC concentration, and shaking time were also studied. The tolerance limits for several metal ions were calculated. The proposed method was applied to the determination of thorium in synthetic solution and in the monazite sand samples with good results.

Size-dependent patterned recognition and extraction of metal ions by a macrocyclic aromatic pyridone pentamer

A macrocyclic aromatic pyridine pentamer was found to exhibit patterned recognition of metal ions and efficiently extract larger ions, such as Cs+, Ba2+, Tl+, Au+, K+ and Rb+ preferentially over the other 18 smaller metal ions from the aqueous phase into the chloroform layer.

The Development and Application of Novel IR and NMR-Based Model for the Evaluation of Carminative Effect ofArtemisia judaicaL. Essential Oil

Artemisia judaicaL. is a medicinal plant that is traditionally used to relieve abdominal pains through its carminative activity. In this study, spectroscopic analysis was employed to investigate the carminative activity associated withA. judaica. Using infrared spectroscopy, the carminative activity was evaluated based on the first derivative of IR-characteristic stretching signal of CO2. Our results indicate thatA. judaicaoil effectively reduced the response of CO2signal equivalent to thymol standard. Additionally,1H-NMR spectroscopy was utilized to assess surface activity ofA. judaicacrude oil through the reduction of interfacial tension in a D2O/CDCl3system. Apparently, 10 mg of the oil was able to solubilize water in a chloroform layer up to 4.3% (w/w). In order to correlate the observed surface activity of the oil to its actual composition, GC-MS and GC-FID structural analysis were undertaken. The results revealed that the oil composition consists of oxygenated terpenes which might be responsible for the carminative effect. Furthermore, owing to its sensitivity, our model provides a fundamental basis for the pharmacological assessment of trace amounts of oils with high precision and accuracy.

Long-chain aliphatic wax esters isolated from the sponge Chalinula saudensis (Demospongia) along the Jeddah coast of the Red Sea

The sponge Chalinula saudensis, which occurs along the Jeddah coast, has only recently been isolated and identified. In this study, the total crude organic matter of the sponge was extracted by solvents. The total crude extract was further separated by partitioning it with hexane and water, then with water and chloroform, and finally with water and t-butanol. The chloroform layer was subjected to separation by preparative layer chromatography on silica. One fraction contained four long-chain fatty acid esters, C28H56O2, C30H60O2, C32H62O2 and C36H70 O2. The second ester, C30H60O2, has been identified in the fire corals Millepora dichotoma and Millepora platyphylla. The others have not previously been reported from marine organisms; however similar long-chain esters with different long aliphatic chains and with different molecular weights have been identified from other marine organisms. These compounds are normally waxy and their presence in Chalinula saudensis plays a vital role in the biosynthetic pathways. They also act as insulators against seasonal variations.

Analisis Pestisida Karbaril dengan metode KLT- Densitometri dalam matriks kedelai dan validasi metodenya

A simple and rapid densitometric method has been developed for determination of low levels of carbaryl in soy bean matrix samples. Sample carbaryl in the soybean matrix was extracted with acetonitril, chloroform and NaCl 0.2 % solution, and the resulting chloroform layer was separated, added sodium sulphate anhydrous to get free of water than evaporated. After dissolution in methanol, the solutions were spotted on silica gel GF254 plates which were then eluted with toluene: ethyl acetate = 3:1 (v/v). Quantitative evaluation was performed by measuring the absorbance reflectance of the analyte spots at λ 280 nm. This densitometric method is selective, precise, accurate and can be used for the determination carbaryl in soy bean matrix.

Extractive Spectrophotometric Methods for the Determination of Rosuvastatin Calcium in Pure Form and in Pharmaceutical Formulations by Using Safranin O and Methylene blue

Two simple extractive Spectrophotometric methods are described for the determination of rosuvastatin calcium (RST) in pure form and in pharmaceutical formulations. These methods are based on the formation of ion association complexes of the RST with basic dyes safranin O (Method A) and methylene blue (Method B) in basic buffer of pH 9.8 followed by their extraction in chloroform. The absorbance of the chloroform layer for each method was measured at its appropriate λmaxagainst the reagent blank. These methods have been statistically evaluated and are found to be precise and accurate.

Organic Components of Moxa

Moxa was soaked in a mixed solvent of chloroform, menthanol and water (5:5:1) at room temperature for 7 days, and the supernatant solution was seperated into two layers by the addition of water. Heptatriacontane (C37H76), confirmed by measurements of 1H and 13C-NMR spectra and melting point, was obtained from the chloroform layer, while condensed tannins having catechol derivatives were found in the methanol-water layer. Each ratio of C37H76 in several kinds of moxas to the total weight of the moxa was similiar in both high-class and low-class moxas, but that of the tannins was much less in the former than the latter. Comparing the burning-temperature from 25°C to the highest temperature was longer in the treated moxa. Removal of C37H76 from the original moxa seems to decelerate the burning of moxa.

Chloroform–Methanol Extraction of Chlorophyll a

Chloroform–methanol (2:1, v/v) extracts significantly more (P < 0.001) chlorophyll a from algal cultures and from freshwater and seawater microcosms than does dimethyl sulfoxide, methanol, absolute methanol with hydrogen sulfide, or 90% acetone. For chlorophyte cultures it yields 97% or more of the chlorophyll a within a 4-h steeping period without grinding. It can be used with both calibrated spectrophotometry and fluorometric instrumentation. Sample filtration onto MgCO3-coated filters is recommended to ensure buffering of the extraction mixture. Holding the filters in chloroform–methanol at 4 °C or room temperature in the dark prevents loss of chlorophyll a for at least 10 d. More refined analyses of phaeophytin and other chlorophylls require the use of chloroform–methanol–water (2:2:1.8, by volume) and placement in a separatory funnel. After 24 h the lower (chloroform) layer contains all of the chlorophyll. Strict pH control is required for pheophytin determinations.

Gas Chromatographic Determination of Diethylstilbestrol Dimethyl Ether in Diethylstilbestrol

A GLC method is described for the determination of the dimethyl ether of diethylstilbestrol (DME) in diethylstilbestrol (DES). A 1 g sample of DES is dissolved in an aqueous solution of 0.5N NaOH and then extracted with a chloroform solution containing benefin, the internal standard. An aliquot of the chloroform layer is chromatographed and the DME peak is measured relative to the internal standard peak. The method was tested for accuracy within the 11–110 ppm range and a linear plot of detector response vs. concentration was obtained.