Isopentyl acetate extractions

Banana (Musa sapientum L.) is one of the most common tropical fruits, and one of Central America s most important crops. It is grown in all tropical regions and is one of the oldest known fruits [45]. From a consumer perspective, bananas are nutritious with a pleasant flavour and are widely consumed throughout the world [57]. Esters predominate in the volatile fraction of banana (Fig. 8.2). Acetates are present in high concentrations in the fruit and generally possess a low threshold. Isopentyl acetate and isobutyl acetate are known as the two most important impact compounds of banana aroma. Alcohols are the second most important group of volatiles in banana extracts. 3-Methyl-1-butanol, 2-pentanol, 2-methyl-1-propanol, hexanol, and linalool are the alcohols present in higher concentrations in the fresh fruit [45]. 

It would be helpful now to study the separation scheme for isopentyl acetate shown in Technique 2, Figure 2.1. Note carefully how the following procedures are shown in a flowchart the extraction step with NaHCOg, the drying step with anhydrous NajSO, and the distillation step. Also note that in this experiment it is not possible to identify with certainty the actual impurities present with isopentyl acetate just before the product is distilled. In some experiments it will be possible to make a good guess about the identity of mosf subsfances at each step in the separation scheme. 

Spec determination by mean centering of ratio kinetic profile (pH = 5.3) Separation and determination of the complex from a tartrate solution at pH > 2 Spec A = 610 nm of complex extracted into isopentyl acetate containing di-n-octylmethylamine... 

Complexing agent for transition metals. Used as 0.5% soln. in AcOH for extraction-photometric detn. of Co (A ax 37000, isopentyl acetate), Ni, Pd, Ru. 

LAS may be determined with great sensitivity by a procedure based on extraction of the ion pair with tetraphenylpyridine into isopentyl acetate, followed by measurement of the absorbance of the extract at 305 nm (10). Interferences are similar to those discussed below for the methylene blue procedure. 

Acetaldehyde diisopentyl acetal Acetylene (29.5 g) is led into isopentyl alcohol (200 g) containing a 63 % solution (10 g) of boron trifluoride in methanol and also some (1 g) mercury(n) oxide. When reaction is over, the solution is washed with a little water and sodium carbonate solution and extracted with ether. The ethereal solution is dried over K2C03 and fractionated. 

In the isolation procedure, much of the excess acetic acid and the remaining isopentyl alcohol are removed by extraction with sodium bicarbonate and water. After drying with anhydrous sodium sulfate, the ester is purified by distillation. The purity of fhe liquid product is analyzed by performing a microscale boiling point determination or infrared spectroscopy. 

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