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Micro apparatus and miscellaneous tools
ABSTRACTS
421
Compounds related to a possible precursor of diploicin, C. R. Smith, Jr., J. Org. Chem., 25,588-91 (1960). The acylation of 380 mg. 2,4dichloro8rcinol and 2,4 dichlororcinol-3-benzyl chloride is reported.
ether in micro reflux assembly by use of excess oxalyl
Synthesis and cleavage of N-trimethylsilylpyrrole, R. Fessenden and D. F. Crowe, J. Org. Chem., 25, 598-603 (1960). The reaction of N-trimethylsilylpyrrol (56-
116 mg.) with ethanol is studied under various conditions (anhydrous, aqueous, or acid-cata.lysis). II, H. Kny and B. Witkop, J. Org. Chem., 25, 635-37 (1960). Reaction of acetic acid and hydrogen peroxide on 500 mg. commercial “pure” quebrachamine yields 40 mg. of a base considered to be an Na-acetylhydroxy derivative, CzlHzsN20e, of quebrachamine. Preparation of 20 mg. quebrachamine disulfide and 8 mg. quebrachamine tribromide is also reported.
Quebrachamine.
Micro Apparatus and Miscellaneous Tools Design and use of a refined microelectrophoresis unit, B. W. Grunbaum and P. I. Kirk, Anal. Chem., 32, 564-566 (1960). The apparatus simultaneously analyzes eight 0.01-0.1 ~1. samples. Accurate positioning of precisely cut papers (multistrip) results in high degree of reproducibility. Determination of occluded solvent in organic compounds, C. E. Childs and E. B. Henner, Chemist-Analyst, 49, 26 (1960). Describes device for determination of solvent occluded in any recrystallized (high melting) compound by passing dry air over the melted sample, condensing in a cold trap, and removing by syringe for chromatographic analysis. Improved melting point block, L. A. Jones and C. K. Hancock, Chemist-Analyst,
49,
28 (1960). Describes an aluminum melting point block for three simultaneous melting point determinations up to 350°C. The block is machined from three pieces of aluminum round stock. Simple semimicro suction jilter,
M. J. Mitchell, Chemist-Atiyst, 49, 30 (1960). A simple suction filter for crystalline samples from l-150 mg. is described which permits the easy weighing of the residue.
Gas chromatographk characterization qf organic compounds. 8. Precision gas chromatograph, P. Toth, E. Kugler, and E. Kovats, Helv. Chim. Acta, 42, 2519-
30 (1959). Column temperature is constant to f0.15’, flow meter temperature to 0.5”, gas velocity to &0.50/o, and retention index over a day to *0.6a/& Method for determining the area of spots in paper chromatography, J. S. Knypl and R. Antoszewski, J. Chem. Educ., 37, 49 (1960). A procedure is described for
photographing spots against a millimeter grid to simplify measurement of area.
4E!
ABSTRACTS
Thermal decomposition of KM& A. K. Galwey, J. Chem. Educ., 37, 98-99 (1960). An apparatus is described for decomposition at 210-22O”C., in a vacuum of 4-5 mg. KMnOl. The rise in pressure with time is observed to study decomposition rate. Vessel for small-scale reactions, S. Kasman, J. Chem. Educ., 37, 150 (1960). apparatus, essentially a side arm for a thermometer sealed near the bottom 25 X 150 mm. test tube is suitable for 0.01-0.03M reactions.
The of a
Two thermocouples suitable for measurement of temperatures up to 28OO”C., D. A. Davies, J. Ski. Znstr., 37,15-17 (1960). The characteristics of two thermocouples: tungsten 26% rhenium-tungsten and tantalum-26% rhenium-tungsten are given. The method of determining emf up to 2300°C. is also described. Design of laboratory furnaces, P. I. Start and M. W. Thring, J. Sci. Znstr., 37, 1724 (1960). A comprehensive paper describing types of furnaces, their construction details, elements, refractories, insulation, and control is presented. High temperature burner for working silica, J. Conaboy, J. Sci. Znsfr., 37,37 (1960). A burner is described which uses propane-oxygen and hydrogen and is capable of producing low pressure flame about 200” C. hotter than oxy-hydrogen and 300°C. hotter than oxygen-propane flames. An electromicrobalance for weighing j&es, F. R. Morgan, J. Sci. Z&r., 37, 53-54 (1960). An electromicrobalance of the meter-torsion type is described. The balance utilizes simple circuit, has a capacity of about 1.5 mg. and weighs to 1 pg. A simplijed calculation formula for use in calibrating capillary burets, M. Pebar, Micro&em. J., 4,73-75 (1960). A uniform calibration technique and a simplified method for calculation are described. The isolation of microbalances against vibrations, E. Kissa, Microchem. J., 4, 8995 (1960). Three types of balance mounts were tested for their performance in the laboratory. Note on a flowmeter suited for low flow rates, W. Simon and G. H. Lyssy, Mikrochim. Acta, 1960, 113-17. The flowmeter is intended for combustion trains. A fractional micro-sublimation technique, W. H. Melhuish, Nature, 134, 193334 (1959). A simple technique is described and the apparatus diagrammed which is used for the separation of aromatic hydrocarbons with high melting points.
MICROCHEMICAL
JOURNAL,
VOL.
IV,
ISSUE
3
421
Compounds related to a possible precursor of diploicin, C. R. Smith, Jr., J. Org. Chem., 25,588-91 (1960). The acylation of 380 mg. 2,4dichloro8rcinol and 2,4 dichlororcinol-3-benzyl chloride is reported.
ether in micro reflux assembly by use of excess oxalyl
Synthesis and cleavage of N-trimethylsilylpyrrole, R. Fessenden and D. F. Crowe, J. Org. Chem., 25, 598-603 (1960). The reaction of N-trimethylsilylpyrrol (56-
116 mg.) with ethanol is studied under various conditions (anhydrous, aqueous, or acid-cata.lysis). II, H. Kny and B. Witkop, J. Org. Chem., 25, 635-37 (1960). Reaction of acetic acid and hydrogen peroxide on 500 mg. commercial “pure” quebrachamine yields 40 mg. of a base considered to be an Na-acetylhydroxy derivative, CzlHzsN20e, of quebrachamine. Preparation of 20 mg. quebrachamine disulfide and 8 mg. quebrachamine tribromide is also reported.
Quebrachamine.
Micro Apparatus and Miscellaneous Tools Design and use of a refined microelectrophoresis unit, B. W. Grunbaum and P. I. Kirk, Anal. Chem., 32, 564-566 (1960). The apparatus simultaneously analyzes eight 0.01-0.1 ~1. samples. Accurate positioning of precisely cut papers (multistrip) results in high degree of reproducibility. Determination of occluded solvent in organic compounds, C. E. Childs and E. B. Henner, Chemist-Analyst, 49, 26 (1960). Describes device for determination of solvent occluded in any recrystallized (high melting) compound by passing dry air over the melted sample, condensing in a cold trap, and removing by syringe for chromatographic analysis. Improved melting point block, L. A. Jones and C. K. Hancock, Chemist-Analyst,
49,
28 (1960). Describes an aluminum melting point block for three simultaneous melting point determinations up to 350°C. The block is machined from three pieces of aluminum round stock. Simple semimicro suction jilter,
M. J. Mitchell, Chemist-Atiyst, 49, 30 (1960). A simple suction filter for crystalline samples from l-150 mg. is described which permits the easy weighing of the residue.
Gas chromatographk characterization qf organic compounds. 8. Precision gas chromatograph, P. Toth, E. Kugler, and E. Kovats, Helv. Chim. Acta, 42, 2519-
30 (1959). Column temperature is constant to f0.15’, flow meter temperature to 0.5”, gas velocity to &0.50/o, and retention index over a day to *0.6a/& Method for determining the area of spots in paper chromatography, J. S. Knypl and R. Antoszewski, J. Chem. Educ., 37, 49 (1960). A procedure is described for
photographing spots against a millimeter grid to simplify measurement of area.
4E!
ABSTRACTS
Thermal decomposition of KM& A. K. Galwey, J. Chem. Educ., 37, 98-99 (1960). An apparatus is described for decomposition at 210-22O”C., in a vacuum of 4-5 mg. KMnOl. The rise in pressure with time is observed to study decomposition rate. Vessel for small-scale reactions, S. Kasman, J. Chem. Educ., 37, 150 (1960). apparatus, essentially a side arm for a thermometer sealed near the bottom 25 X 150 mm. test tube is suitable for 0.01-0.03M reactions.
The of a
Two thermocouples suitable for measurement of temperatures up to 28OO”C., D. A. Davies, J. Ski. Znstr., 37,15-17 (1960). The characteristics of two thermocouples: tungsten 26% rhenium-tungsten and tantalum-26% rhenium-tungsten are given. The method of determining emf up to 2300°C. is also described. Design of laboratory furnaces, P. I. Start and M. W. Thring, J. Sci. Znstr., 37, 1724 (1960). A comprehensive paper describing types of furnaces, their construction details, elements, refractories, insulation, and control is presented. High temperature burner for working silica, J. Conaboy, J. Sci. Znsfr., 37,37 (1960). A burner is described which uses propane-oxygen and hydrogen and is capable of producing low pressure flame about 200” C. hotter than oxy-hydrogen and 300°C. hotter than oxygen-propane flames. An electromicrobalance for weighing j&es, F. R. Morgan, J. Sci. Z&r., 37, 53-54 (1960). An electromicrobalance of the meter-torsion type is described. The balance utilizes simple circuit, has a capacity of about 1.5 mg. and weighs to 1 pg. A simplijed calculation formula for use in calibrating capillary burets, M. Pebar, Micro&em. J., 4,73-75 (1960). A uniform calibration technique and a simplified method for calculation are described. The isolation of microbalances against vibrations, E. Kissa, Microchem. J., 4, 8995 (1960). Three types of balance mounts were tested for their performance in the laboratory. Note on a flowmeter suited for low flow rates, W. Simon and G. H. Lyssy, Mikrochim. Acta, 1960, 113-17. The flowmeter is intended for combustion trains. A fractional micro-sublimation technique, W. H. Melhuish, Nature, 134, 193334 (1959). A simple technique is described and the apparatus diagrammed which is used for the separation of aromatic hydrocarbons with high melting points.
MICROCHEMICAL
JOURNAL,
VOL.
IV,
ISSUE
3