Methoxyl Determination

A yellow or brownish liquid of specific gravity 1.70. The acid contains about 57 per cent of HI and is used for methoxyl determination, according to Zeisel. 

Elemental analysis was carried out by Micro-Tech Laboratories, Skokie, 111., and methoxyl determinations were performed by the Georgia Pacific Co., Bellingham, Wash. 

Apparatus The apparatus for methoxyl determination, as shown in Fig. 29, consists of a boiling flask, A, fitted with a capillary side arm to provide an inlet for carbon dioxide and connected to a column, B, which separates aqueous hydriodic acid from the more volatile methyl iodide. After the methyl iodide passes through a suspension of aqueous red phosphorus... 

Wc shall lake up other quantitative analytical methods when we need them nitrogen and sulfur analysis, Sec. 10.12 methoxyl determination. Sec. 17.16 neutralization equivalent, Sec. 18.21 saponification equivalent, Sec. 20.24.)... 

USE Reducing agent, manuf of inorganic iodides, pharma -ceuiicals. disinfectants. The 57% acid is also used for analytical purposes, such as methoxyl determinations. Camion Strong irritant. 

The extent (completeness) of the methylation reaction can be monitored by methoxyl determination if sufficient material is available or on a microscale by the absence of O-H stretching vibrations ( 3400 cm ) in the infrared spectrum. If the extent of undermethylation is significant the methylation procedure ought to be repeated. The points of undermethylation can be located by using deuterated methyl iodide or ethyl... 

The chief perplexities encountered in the identification and determination of the structure of a C-glycosyl compound are those to be expected in the handling of polyhydroxy compounds, namely, difficulties in purifying the starting material and uncertainties in the determination of the degree of hydration and the number of hydroxyl groups. For the latter, complete methylation and subsequent methoxyl determination seems to provide the most reliable method. 

No fau on was obtained below 230, so that terpenes were clearly abeent. No aldehydes were present. A methoxyl determination showed theiwesenoe of 16 16 TOr cent, of CHjO. As safrol contains no methoxyl it is obvious that other ethers are present. A complete fractionation resolved the oil into the following fractions —... 

Myristicin, however, only contains one methoxyl group, whilst the methoxyl determination showed that more methoxyl was present thtm is indicated by the amount of myristicin found. A trimethoxy compound was suspected to be present, but, unfortunately, could not be isolated in a sufficiently pure state for identification. Trimethyl-gallic acid was found in the oxidation products, which agreed with the presence of iso-elemicin in the oil, which had first been treated with alcoholic potash. Therefore, elemidn was probably present in the original oil. Iffiis was confirmed by preparing the crystalline dibromide of iso-elemicin, which melted sharply at 88 to 89. Elemicin, which was isolated from oil of elemi by Semmler, has the formula CeH.(OCH.), (OHj. OH CHj). 

Goodson and Henry concluded that the discrepancy occurring between the specific rotation and that calculated from the composition of the mixture as determined by methoxyl determination was due to cinchonine precipitated with the quinine and cinchonidine. This can be avoided by precipitation of the tartrates from slightly acid solutions, or their reprecipitation prior to taking polarimetric readings as described above. 

Methanol and acetone tests (27) Methoxyl determination (53) Water-soluble substances... 

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