Pentasol

The most widely used complexing agents are alcohols (butanol, n-propyl alcohol and n-pentyl alcohol1). Schoch33 now recommends the use of Pen-tasol, a commercial mixture of pentyl alcohols, for the first precipitation, and 1-butanol for recrystallizations. For com (maize) starch, this avoids contamination of the amylopectin with an intermediate fraction which is sufficiently linear to be precipitated with Pentasol and yet has a degree of branching which prevents complex formation with butanol. 

Alternate names Chem-Penta, Chemtrol, Chlorophen, Dow Pentachlorophenol, Dowicide 7, Dowicide EC-7, Dowicide G, DP-2, Durotox, Lauxtol A, OntrackWE-1, PCP, Penchlorol, Penta, 2,3,4,5,6-pentachlorophenol, Penta General Weed Killer, Pentacon, Penta-kil, Pentanol, Pentasol, Penwar, Permacide, Permaguard, Permasem, Permatox, Priltox, Santobrite, Santophen, Sinituho, Term-l-trol, Weed-Beads, Weedone... 

PENTASODIUM TRIPHOSPHATE see SKNOOO PENTASOL see PAX250 PENTASOL see AOEOOO... 

While specifically developed for fractionating com starch with Pentasol, the following procedure is applicable to any starch and to any of the precipitants indicated above ... 

The yields of A-fraction by the above method are substantially higher than the 22-23% previously reported by butyl alcohol fractionation, since the latter method does not give as complete a separation. From the iodine adsorption of raw corn starch and of the purified A-fraction, Bates, French and Rundle have calculated the content of A-fraction in corn starch as 22%. This low value is due to the use of incompletely defatted starch, and its agreement with the yield by butyl alcohol precipitation is purely coincidental. Under preferred methods of testing, exhaustively defatted corn starch adsorbs 5.3% iodine. Dividing this latter value by the 19.0% iodine adsorption for the recrystallized A-fraction, a theoretical content of 28% is calculated for corn starch, in agreement with the yields by Pentasol fractionation. 

No satisfactory method has been found for removing the 3-4% of A-fraction presumably remaining in the Pentasol non-precipitated B-traction. Bates, French and Rundle have suggested that this may be removed by repeated treatment with cotton. Attempts to apply this purification have not been successful. Various grades of cotton, cellulose pulp, charcoal, activated alumina, precipitated aluminum hydroxide, bentonite and fuller s earth have been tested, without any significant improvement in the purity of the B-fraction. It is possible that Bundle s cotton treatment may introduce traces of lipid material (fatty acids or sterols) which mask the iodine adsorption. 

Fractionation of various starches. A wide variety of starches should be separated by Pentasol precipitation, to determine the distribution of the fractions. Comparison of the physical properties of the purified fractions from typical starches (especially corn, wheat, rice, potato, tapioca, canna, lily and arrowroot) should clarify specific differences in chemical structure. 

In order to effect complete dissolution of starch at temperatures below 100°, Bauer and Pacsu recommended the use either of dilute alkali or of dilute acid solutions. Accoixling to their so-called alkali process, defatted corn starch is dissolved in 0.5 to 1.0 N alkali at room temperature. Sufficient mineral acid is added to the resulting solution to bring its pH within the limits of 10-4. After saturation with (for example) Pentasol (a mixture of primary amyl alcohols), the system is heated for several minutes at a temperature between 60° and 100° on cooling, an amylose precipitate is obtained which can readily be separated in an ordinary, industrial centrifuge. Addition of excess methanol to the supernatant liquor causes precipitation of the amylopectin. Different kinds of starches can be fractionated by this method. Starch concentrations of up to 5% are claimed to give about a 24% yield of amylose (showing an iodine value of 16.0%) and a 76% yield of amylopectin (with a 0.9% iodine absorption). 

Pentasol 7 8 laat tan Monsento Lusttex 50.8 mm dlsm. disc... 

In the absence of any color, test io cc. of the sample in the same manner, using sufficient fusel oil, amyl alcohol or pentasol to nearly fill the tube, and shake several times. A deeply colored lower layer is an indication of a coal tar dye its identity should be confirmed by using the methods under 51. 

PENTASOL (87-86-5) Decomposes in water, forming hydrochloric acid, chlorinated phenols, and carbon monoxide. Incompatible with strong oxidizers, aluminum chloride, nitrobenzene, butadiene. Attacks light metals in the presence of moisture. 

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