Reference

Liquid chromatography

Liquid chromatography. Ozawa, Mitsuru; Tomita, Yutaka (Zaidan Hojin Kagakuhin Kensa Kyokai, Japan). Jpn. Kokai Tokkyo Koho JP 61140861 A2 27 Jun 1986 Showa, 11 pp. (Japan) CODEN: JKXXAF. CLASS: ICM: G01N030-46. ICS: B01D015-08. APPLICATION: JP 84-263872 14 Dec 1984. DOCUMENT TYPE: Patent CA Section: 80 (Organic Analytical Chemistry) The title device comprises a concn. column between 2 columns for different sepn. modes. A solvent is selected so that when it is mixed with the eluate from the 1st column, the components to be detd. in the eluate from the 1st column can be concd. in the concn. column. After the components are concd. in the concn. column, a soln., which also acts as an eluent for the 2nd sepn. column, is introduced to the concn. column to elute the concd. components and the eluate from the concn. column is introduced into the 2nd sepn. column.Several substances with their cas registry numbers 99-71-8 and 108-38-3 may be metioned in this study. The 1st column may be a gel permeation chromatog. (GPC) column using an org. solvent eluent and the 2nd column may be a reverse-phase-partition-type ODS column. H2O may be added to the eluate from the 1st column. Thus, by using this device, benzene was sepd. from toluene in a sample contg. 2,4,6-trimethylphenol and p-sec-butylphenol as impurities. THF was used as the eluent for the 1st column. H2O was used as the solvent to be mixed with the eluate from the 1st column. Then H2O only was introduced into the concn. column and the eluate from the concn. column was introduced into the 2nd column. For comparison, benzene could not be sepd. from 2,4,6-trimethylphenol and toluene could not be sepd. from p-sec-butylphenol when only the ODS column was used and benzene could not be sepd. from toluene when only the GPC column was used. .

The association of 1-methyl-2,5-pyrrolidinedione and dihydro-2(3H)-thiophenone with phenols

The association of 1-methyl-2,5-pyrrolidinedione and dihydro-2(3H)-thiophenone with phenols.There are some reagents like 99-71-8 is used in this study. Jarva, M. (Dep. Chem., Univ. Oulu, Oulu, Finland). Finn. Chem. Lett., (4), 145-8 (English) 1978. CODEN: FCMLAS. 99-71-8 is also in the experiment. ISSN: 0303-4100. DOCUMENT TYPE: Journal CA Section: 22 (Physical Organic Chemistry) The assocn. of 1-methyl-2,5-pyrrolidinedione and dihydro-2(3H)-thiophenone with PhOH and 8 p-substituted phenols was studied by near-IR spectrophotometry at 15, 25, 35 and 45° in CCl4 soln. The fit between the data for the formation of the 1:1 complex and the Hammett equation is fairly good. The H-bonding ability of dihydro-2(3H)-thiophenone is lower than that of the O analog and that of 1-methyl-2,5-pyrrolidinedione is considerably lower than that of 1-methyl-2-pyrrolidinone. ..