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A simple device for maintaining a constant pressure in liquid-solid chromatography
Fig. 2. Microelec&ropho&sis &I: agarose gel of mucopoly~accharides. Barbitxmate buffer PI-I 8.6: Tol_-ufdine Blue &_siniu~. Absolute amount of ma,terisl annlied on the &_rinr- I (a.1 c: +v -v& ,DI ---c-- --- o. .--I hnnmin CI. --------cr---(b) chondroitin-sulphuric acid A 0.5 y: (c) hyaluronic acid 0.5 y.
The authors are indebted to’ Drs. SZIRMAYand .DOYLE, University Hospital Leyden, for supplying a sample of chondroitin-sulphuric acid and a sample of hyaluronic acid.
z R. J. WIEML, Studies on Agav Gel Electrophovesis, Editions Arscia; Brussels, 2 C. ARAKI, Intern. Congr. Biochem., &la, Vienna, rg58. Vol. I (1959) 15. AND R. E; BALLIEUX,~ preparation. 3 L. B. JAQUES, CVAN'ARKEL rLS. WJERTEN, Biocltim: Biophys. Acta, 53 (1961) 514. G J,. ,F. HEREMANS AND J. VAERMhN, Gba. Chim. Ada, 3 (1958) 430.
1959.
.
J, ChYomatOg., II (1963) 421-423
A simple device for maintaining
a constant pressure
in liquid-solid,chromatography
i
In liquid-solid chromatography work it is generally necessary to exert a pressure on the eluant solution, so that it passes through’the column at the required flow rate. In order to have a constant flow rate during a run (after the solid adsorbent has packed down) it is necessary to maintain a constant air pressure on ‘the eluant. In general, the required pressure is not very high and, according to the case, varies from 50 to 400 mm Hg. A low pressure compressed air line is therefore necessary, and it is important that the pressure does not undergo considerable changes. In our laboratory an efficient constant pressure device has been set up. It is illustrated in Fig, I, variations of pressure do not exceed !1-2 mm Hg. The device is easily constructed, and has been used successfully during several months of uninterrupted work. J, Chvomatog.,
II (1963) 423-424
NOTES
424
The air compressor A provides air at a pressure of 8-g kg/cm2 which is reduced to the required value by the @ressure reducing.valve C and is then collected in the receiver E. The air at low pressure in E then passes solenoid valve F and goes on one side to the
Fig. I. Schematic diagram of device. A = Air compressor. B = Nigh prcssurc line. C = Pressure reducing valve, D = Low pressure line. I3 = Low pressure air reservoir (capacity: 20 1). F = Solenoid valve. G = Eluant reservoir. El = Column. I = Movable electric contact. K = U-shaped tube. L = Fixed electric contact. M = Relay. N = Stopcock.
eluant solution contained in the reservoir G connected by an air-tight joint to the chromatographic column H. On the other side it passes into the U-shaped tube I< containing mercury, which is in electrical contact with the relay M through L. The air pressure causes the mercury to rise in the branch of the U-shaped tube in which there is a movable contact 1. When the mercury reaches this contact, it closes the circuit between I and,L in such a way that it operates the relay M which opens the feeding contact of the solenoid valve F, which closes and stops the compressed air flow. Thus the pressure in the apparatus to the right hand side of the solenoid valve will rmnain “II&L1 ~Ya~*uLII
rnnc+an+ c~,f UVAAI” CARP ntr~fi~&l YVI&.aCULIC UC ~~“vIC_YU
v~llrrn ” WAUV rlmwanclm~f UYyYIIUYLI”
r\m IPVP~ V&I 4hm LA&M .L” ““A
nf chm VL T I rtnltacc UIIIIIU b-4”
pressure is lowered, as a result of a fall in the eluant solution level, or owing to a small leak. The mercury meniscus then .breaks contact with 1; the relay closes the feeding contact, the solenoid opens to admit .air from E which raises the mercury levels and re-establishes the contact between I and L. By adjusting’ the pressure at a value slightly higher than the pressure required in the column, the variations of the air pressure in this section will not be more than 1-2 mm Hg. n’___-..‘._1.Y _%.._*_ ..._
*
mxearcn Laooyaboyy, Com$agnia Iihfiana Liebig S.J?LA., Tovtona (Italy)
Received November
ft.
e _-__.__bAKlSAN
z6th, 1962 J.
CkYOWZtZtO~.,
I I
(1963)
423-424
0
The authors are indebted to’ Drs. SZIRMAYand .DOYLE, University Hospital Leyden, for supplying a sample of chondroitin-sulphuric acid and a sample of hyaluronic acid.
z R. J. WIEML, Studies on Agav Gel Electrophovesis, Editions Arscia; Brussels, 2 C. ARAKI, Intern. Congr. Biochem., &la, Vienna, rg58. Vol. I (1959) 15. AND R. E; BALLIEUX,~ preparation. 3 L. B. JAQUES, CVAN'ARKEL rLS. WJERTEN, Biocltim: Biophys. Acta, 53 (1961) 514. G J,. ,F. HEREMANS AND J. VAERMhN, Gba. Chim. Ada, 3 (1958) 430.
1959.
.
J, ChYomatOg., II (1963) 421-423
A simple device for maintaining
a constant pressure
in liquid-solid,chromatography
i
In liquid-solid chromatography work it is generally necessary to exert a pressure on the eluant solution, so that it passes through’the column at the required flow rate. In order to have a constant flow rate during a run (after the solid adsorbent has packed down) it is necessary to maintain a constant air pressure on ‘the eluant. In general, the required pressure is not very high and, according to the case, varies from 50 to 400 mm Hg. A low pressure compressed air line is therefore necessary, and it is important that the pressure does not undergo considerable changes. In our laboratory an efficient constant pressure device has been set up. It is illustrated in Fig, I, variations of pressure do not exceed !1-2 mm Hg. The device is easily constructed, and has been used successfully during several months of uninterrupted work. J, Chvomatog.,
II (1963) 423-424
NOTES
424
The air compressor A provides air at a pressure of 8-g kg/cm2 which is reduced to the required value by the @ressure reducing.valve C and is then collected in the receiver E. The air at low pressure in E then passes solenoid valve F and goes on one side to the
Fig. I. Schematic diagram of device. A = Air compressor. B = Nigh prcssurc line. C = Pressure reducing valve, D = Low pressure line. I3 = Low pressure air reservoir (capacity: 20 1). F = Solenoid valve. G = Eluant reservoir. El = Column. I = Movable electric contact. K = U-shaped tube. L = Fixed electric contact. M = Relay. N = Stopcock.
eluant solution contained in the reservoir G connected by an air-tight joint to the chromatographic column H. On the other side it passes into the U-shaped tube I< containing mercury, which is in electrical contact with the relay M through L. The air pressure causes the mercury to rise in the branch of the U-shaped tube in which there is a movable contact 1. When the mercury reaches this contact, it closes the circuit between I and,L in such a way that it operates the relay M which opens the feeding contact of the solenoid valve F, which closes and stops the compressed air flow. Thus the pressure in the apparatus to the right hand side of the solenoid valve will rmnain “II&L1 ~Ya~*uLII
rnnc+an+ c~,f UVAAI” CARP ntr~fi~&l YVI&.aCULIC UC ~~“vIC_YU
v~llrrn ” WAUV rlmwanclm~f UYyYIIUYLI”
r\m IPVP~ V&I 4hm LA&M .L” ““A
nf chm VL T I rtnltacc UIIIIIU b-4”
pressure is lowered, as a result of a fall in the eluant solution level, or owing to a small leak. The mercury meniscus then .breaks contact with 1; the relay closes the feeding contact, the solenoid opens to admit .air from E which raises the mercury levels and re-establishes the contact between I and L. By adjusting’ the pressure at a value slightly higher than the pressure required in the column, the variations of the air pressure in this section will not be more than 1-2 mm Hg. n’___-..‘._1.Y _%.._*_ ..._
*
mxearcn Laooyaboyy, Com$agnia Iihfiana Liebig S.J?LA., Tovtona (Italy)
Received November
ft.
e _-__.__bAKlSAN
z6th, 1962 J.
CkYOWZtZtO~.,
I I
(1963)
423-424
0