JPH05256756A - Continous wave membrane osmometer - Google Patents

Abstract

PURPOSE: To obtain a membrane osmometer capable of continuously measuring and rapidly replacing a sample. CONSTITUTION: The continuous wave membrane osmometer comprises a coaxial glass capillary tube membrane 14 disposed in a solvent chamber 16, and connectors 22, 24 provided to feed sample solution. The chamber 16 can be set to the off state and is connected to a pressure sensor 42. It can statically or in-line measure. Since it has a small size, its responding time is short. The membrane has chemical resistance.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a membrane osmometer having the features described in the preamble of claim 1.

[0002]

BACKGROUND OF THE INVENTION Known membrane osmometers need improvement in many respects. This device often has a long response time. The membranes used often have to be set up against current solvents due to cumbersome treatments, and their chemical resistance is often imperfect. Rapid sample exchange is difficult and continuous measurement of flowing samples is not possible.

[0003]

SUMMARY OF THE INVENTION The present invention aims to develop a membrane osmometer based on the preamble of claim 1 and, in particular, to enable more rapid sample exchange. is there. The osmometer can be used as a novel type of detector for liquid chromatographic separation methods.

[0004]

According to the invention, the object is achieved by providing a membrane osmometer based on the preamble of claim 1 comprising the characterizing part of claim 1. Further features and advantages of the membrane osmometer according to the invention are the subject matter of the dependent claims.

The membrane osmometer according to the invention allows continuous measurements and rapid sample exchange. Its construction is simple and requires little maintenance. Semipermeable membranes consisting of glass capillaries are distinguished by high chemical resistance. The measurement is almost unaffected by variations in sample pressure or solvent flow.

The membrane osmometer of the present invention can be used for most of a variety of purposes, eg, the numerical average molecular weight of different polymers in any solvent that can also be used in chromatography. Concentration- or molecular-weight-dependent measurements that can be performed in-line, i.e., statically or continuously in a continuous flow, i.e. Can be used to do

Since the measuring cell of the osmometer can be made of a transparent material, it can be combined with other sensing methods that operate simultaneously, especially optical sensing methods.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A membrane osmometer according to a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

The membrane osmometer in the preferred embodiment has a replaceable measuring cell cartridge having a small volume of about 100 μl. This measuring cell cartridge comprises a glass tube 10 with two annular recesses 54 and two radial bores 23, a glass capillary membrane 14 and a corresponding seal around the glass capillary membrane. There is. The measurement cell cartridge is
With respect to the seal 55, by means of the back nut 17 and the screw 56, the two half shells 13 made of plastic material
Is clamped by. Therefore, the measuring cell cartridge is reversibly replaceable and the union 20
And is sealed at the ends relatively. A glass capillary membrane 14 fitted in a tube 10 made of glass or other suitable substance and having its ends sealed to the solvent is a glass capillary tube in which the sample solution introduced via line 24 is a glass capillary tube. It is immobilized so that it can flow only through the interior of the membrane and can only be mixed with the pure solvent around the glass capillary membrane 14 by the diffusion process through the glass capillary membrane 14. The interior of the glass tube 10 is divided by a membrane 14, which is a rigid glass capillary tube that extends into the solvent chamber 16 outside the glass capillary membrane 14 and the sample solution chamber 18. The glass capillary membrane is aligned and aligned in a manner sealed with an organic or inorganic sealing material 12.
Although fixed in 0, the flow is allowed to flow through the inside of the union 20 and lines 24 and 22 feed and drain the sample solution, respectively. The sealing substance 12 has an effective resistance to the solvent, and does not cure to shrink or swell nor bulge.

The tube 10 has two side attachments 2
6, 28 are provided, which have bores bored therethrough for receiving the glass tube 10 and have an extension suitably screwed for mounting. Plugs 32 and 34 made of PTFE are attached to the attachment 26, respectively.
And 28 and having a capillary made of stainless steel to reduce the volume.
The plugs 32 and 34 are sealed to the bore 23 by a back nut 35 by their screws 36.

The end of the plug 23 facing away from the solvent chamber 16 is connected to the pressure sensor 42 by means of a screw, and the pressure sensor 42 is connected by a capillary tube 30 to the purge valve 4.
4 is connected. The end of the plug 34 facing away from the solvent chamber 16 is connected to the same purge valve 44 by a capillary tube 50. The purge valve 44 allows the connection 23 to be opened to the solvent chamber 16 at the same time for filling, discharging and readjustment of the solvent.

Back nut 1 provided with a bore therethrough
9 adjusts the quartz glass window with screws 21 and seals them relative to the union 20 via a seal 53. This configuration, in the longitudinal axis direction,
It is possible to pass the laser beam through the sample chamber 18. With this configuration, it is possible to perform interference refraction index measurement at the same time as permeation measurement, and therefore it is possible to determine the actual sample concentration (kg / m ³ ) in the measurement cell cartridge without time shift Is.

In operation, the sample solution to be tested is supplied via line 24 into or through the glass capillary membrane 14. In the solvent chamber 16 surrounding the capillary tube 14, an osmotic pressure reduction is established in proportion to the ratio of the concentration to the molecular weight of the sample, which is detected by the sensor 42 and is connected to a pressure sensor such as a computer, a recorder or the like. Recorded or displayed by receiver 48.

The volume of the solvent chamber 16 and the sample solution chamber 18 is very small, preferably 100 μl or less in total, more preferably 50 μl or less, and the solvent chamber 16 is closed and very hard. Thus, there are very few solvent molecules that must diffuse through the membrane 14 to obtain the final pressure, and the membrane wall thickness is very small and the response speed is high.

With the present membrane osmometer, it is possible to test any sample solution that does not attack glass, stainless steel and PTFE.
The size of the pores in the glass capillary membrane determines the lower exclusion limit and the concentration of the sample solution determines the upper exclusion limit.

In the preferred embodiment, the tube 10 is constructed of glass and has an inner diameter of 2 mm and a length between the plugs 12 of 80 mm. The total volume of the sample chamber and sample solvent chamber is 50 μl.

The glass capillary forming the membrane 14 has an inner diameter of 1 mm and a wall thickness of 50 μm, and tempers or filters the borosilicate glass, which causes phase separation during this treatment. One phase is filtered out and small pores are formed) and is formed from quartz glass.

In order to facilitate bubble-free flushing on the solvent side, ie, the discharging operation, a solvent supply line 52 to the valve 44 is permanently connected to a supply container (not shown) via a hose connection and a solvent discharge line 51. Connection, so that the solvent side is evacuated, for example due to the pressure difference between the solvent source and the solvent recovery container.

The specific embodiments of the present invention have been described above in detail, but the present invention should not be limited to these specific examples, and various modifications can be made without departing from the technical scope of the present invention. Of course, it can be modified.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view showing a continuous flow membrane osmometer constructed according to a preferred embodiment of the present invention.

[Explanation of symbols]

 10: Glass tube 14: Glass capillary membrane 16: Solvent chamber 18: Sample solution chamber 19: Back nut 20: Union 26, 28: Side attachment 32: Plug 42: Pressure sensor 44: Purge valve

Claims (7)

[Claims] 1. A sample solution chamber (18) and a solvent chamber (1)
6) and a semipermeable membrane (1
4) and a membrane osmometer having a pressure measuring device (42) connected to one of the chambers,
The chamber (14) has a connection (22, 2) for the sample solution.
4) having the shape of a tube, the solvent chamber surrounding the tubular membrane (14) and being sealable, and the pressure measuring device (42) being the solvent chamber (1).
Membrane osmometer characterized in that it is connected to 6). 2. The membrane (1) according to claim 1,
A membrane osmometer characterized in that 4) is a capillary tube. 3. The membrane (1) according to claim 1,
4) The membrane osmometer characterized in that the solvent chamber (16) and the solvent chamber (16) have the shape of a coaxial tube. 4. The membrane osmometer according to any one of claims 1 to 3, wherein the membrane is made of glass. 5. The solvent chamber (16) according to any one of claims 1 to 4, wherein the solvent chamber (16) is a transparent component (1).
Membrane osmometer characterized by being surrounded by 0, 15). 6. Membrane according to any one of claims 1 to 5, characterized in that the solvent chamber (16) comprises two pipe joints and means for closing the joints. Osmometer. 7. Membrane osmometer according to any one of claims 1 to 6, characterized in that the volume of the solvent chamber (16) is at most 100 μl.