(6) Tatm-awadi, F. V , , Bard, A . J., The University of Tesas, Austin, Tesas, unpublished dat,a, 1963. HARVEY B. HERMAN SHASKAR V. TATWAWADI ALLENJ. BARD Department of Chemistry The University of Texas Austin 12, Texas RECEIVEDfor review July 24, 1963. Accepted September 23, 1963. Work supported by a grant of the Robert A. Welch Foundation.
LITERATURE CITED n d w i bed I)lod\ict OC< u -S c 1 ~ l ~ d t ~ L i l C ~ ~ ~ ~ ~ l y \\ ith oxidatioii of the diffusing species, calculations based on this model will (1) Berzins, T., Delahny, P., J . A n i . Chenz. SOC.75, 420.5 (1953). yicld a value of r 151iich is somewhat (2) BrdiEka, R., CoZlectio)i Czech. Chenz. low. -4s in all cases o ' chioiiopotciitioCommun. 12, 522 (1947). metric measurenicnt~clf ad,orption, the (31 . . Lorenz, W..Z. Elektrochem. 59. 730 value of r obtained must be regarded as (1955). ( 4 ) Lorenz, W., Muhlberg, H., Ibid., an ettimate. A subequent communica59, 736 (1955); 2. Physik. Chem. tion will further discuc,t the inodel preFrankfurt 17, 129 (1958). beiited Iiertl, a$ well as other models for (5) Osteryoung, R. A., ANAL.CHEM.35, cwreiit i m ci ~1 cIiI.oiioi)oteiitiometr3'. 1199 (1963). I
.
Solvents for Phosphorimetry SIR: The development of phosphoriinetry as a means of analysis is highly dependent on the availability of solvents which form clear rigid glasses rather than cracked glasses or snows when cooled down to liquid nitrogen temperature. Phosphorimetry as a means of chemical analysis was introduced in 1957 by Keirs, Britt, and Wentworth (1). I n 1962 a review by Parker and Hatchard (2) appeired. In 1963,
Table I.
Winefordner and Latz (3) analyzed small concentrations of aspirin in blood with negligible interference and indicated that phosphorimetry could be applied to the quantitative analysis of trace concentrations of drugs in biological fluids. For the method of phosphorimetry to be used, suitable solvents must be readily available. Therefore, in this brief communication a large nuriiher of solvents which had
Behavior of Solvents upon Rapid Cooling with Liquid Nitrogen
Frequency of forming Form of media cracks at 77' K. or snow
Kind of solvent Hydrocarbons Pentane (tech.) Clear g1:tss Petroleum ether Clear glass Heptane Clear glass Clear glass Toluene Methyl cyclohexane Clear glass Iso-octane Snow Cyclohexane Snow Benzene Snow m-Xylene Snow Hexane Snow Bases and N-containing Compounds Triethylamine Clear glass Triethanolamine Clear glass Dime t hy 1 formamide Glass or snow Isopropylamine Clear glass Pyridine Snow Diethylamine Snow Dipropylamine Snow Formamide Snow A',-V-dimethylfor mamide Snow Acetonitrile Snow Ethers Diethj 1ether Clear glass Ili-n-propyl ether Clear glass Di-n-butyl ether Clear glass Methyl cellosolve Clear glass Ethyl cellosolve Clear glass Butyl cellosolve Clear glass 1 3methoxymethane Snow Ethyl cellosolve acetate Snow
been preriou4\. described in t h e literature were studied in order to determine the nuniber and kinds of solvents which will form clear rigid glasses at liquid nitrogen temperature. I n Tables I and I1 R large number of solvents and solvent mixture?, which had previously been purified by distillation, column chromatography over alumina, etc., are listed according to type and behavior on cooling down to
Possibility for use
0 out of 10 1 out of 10 9 out of 10 10 out of 10 9 out of 10 10 out of 10 10 out of 10
Excellent Good S o t usable S o t usable S o t usable S o t usable S o t usable 10 out of 10 h'ot usable 10 out of 19 Not usable 10 out of 10 Not usable 5 out of 10 Poor 10 out of 10 S o t usable 10 out of 10
10 out of 10 out of 10 out of 10 out of 10 out of
S o t usable
10 S o t 10 S o t 10 S o t 10 S o t
usahle usable usable usable 10 S o t usable
10 out of 10 S o t usable 10 out of 10 S o t usable 1 out of 9outof gout of 10 out of 10 out of 10 out of 10 out of
10 Good 10 S o t usable 10 Xot usable 10 S o t usable 10 Y o t usable 10 Xot usable 10 S o t usable
10 out of 10 S o t usable
Kind of solvent Di-isopropyl ether 1,sDioxane Alkyl halides Carbon tetrachloride Chloroform Bromoform Dichloromethane Tetrachloroethylene 1-Rromopropane 2-Chloropropane 1,Z-Dibromoethylene 2-Bromobutane 2-Bromopentane Alcohols Methanol Ethanol n-Propanol Isopropanol n-Butanol Isobutanol 4-Chloro-1-butanol Isoamyl alcohol Glycerol Ethylene glycol Miscellaneous Acetone Methyl isobutyl ketone Acetic acid Formic acid Per fluorocarbon oil (Kel F)
Frequency of forming Form of media cracks Possibility a t 77" IC. or snow for use Snow 10 out of 10 Not usable Snow lOout of 10 Not usahle Snow Snow Snow
Snow
Snow Snow Snow
1Oout of lOout of 10 out of 10 out of lOout of 10 out of 10 out of
10 Not usable
Snow Cloudy glass Snow
10 out of 10 Not usable '7 out of 10 Good 10 out of 10 Not usable
Clear glass Clear glass Clear glass Clear glass Clear glass Clear glass Clear glass Clear glass Clear glass Snow
10 out of 1 out of 2 out of 9 out of 4 out of 10 out of 10 out of 8 out of 10 out of 10 out of
Snow
10 out of 10 Not usable
Snow Snow Snow
10 out of 10 Not usable 10 out of 10 Not usable 10 out of 10 Not usable
Snow
10 out of 10 Not usable
10 10 10 10
Not Not Not Not 10 Not 10 Not
usable usable usable usable usable usable
10 Not usable 10 Good 10 Good 10 Not usable 10 Poor 10 X o t usable 10 Not usable 10 Poor 10 Not usable 10 Not usable
VOL. 35, NO. 13, DECEMBER 1963
221 1
Table II.
Behavior of Solvent Mixtures upon Rapid Cooling Volume Form of media ratio at 77' K. Mixture 1,4-Dioxane: diethyl ether 4 to 1 Snow 1,4-Dioxane: heptane Snow 4 to 1 Ethanol: methanol 5 to 1 to 9 to 1 Clear glass Ethanol: glycerol Clear glass 11 to 1 Carbon tetrachloride: pet. ether 1 to 1 to 1 to 2 Snow to glass Ethanol (96%):diethyl ether 2 to 1 Clear glass Ethanol: concentrated HCl 19 to 1 C lear glass Ethanol :water Clear glass
