JP2548874B2 - Chromatographic separation packing material - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a packing material for chromatographic separation, and more particularly to a packing material having silica gel particles as a base material, which can favorably adsorb and separate a basic substance.

[0002]

BACKGROUND OF THE INVENTION It is known to use silica gel particles as a packing material for high performance liquid chromatography, and this chromatography is generally used as adsorption (normal phase) chromatography for the purpose of analyzing or purifying various solutes. ing. This action mechanism is basically based on the interaction with the solute on the surface of silica gel, but it is said that the hydrogen bonding property with the solute by the surface silanol (Si-OH) group of silica gel is the main.

However, the surface silanol group may be dissociated to be in an acidic state and exhibit an ion-exchange-like action. Especially, when the solute is a basic substance, it forms an ionic bond with silica, resulting in abnormally strong adsorption. As a result, there was a drawback that the adsorption separation of the basic substance by chromatography could not be performed well.

[0004]

In view of the above situation, the present invention intends to provide a method for easily and surely performing adsorption separation of a basic compound in a chromatographic separation technique using silica gel particles as a packing material. To do.

[0005]

Means for Solving the Problems The present inventors have conducted various studies to achieve the above object, and as a result, when silica gel particles used as a packing material for chromatographic separation were treated with a magnesium compound, The present invention has been completed by finding that even if a basic compound is contained in the compound, the compound can be favorably adsorbed and separated.

That is, the gist of the present invention is magnesium
Adjust the pH to 5.5 or higher by immersing the silica gel in the salt solution.
A packing material for chromatographic separation, which comprises silica gel particles obtained by isolating and drying the silica gel after the preparation and holding. Hereinafter, the configuration of the present invention will be described in detail. The silica gel particles to be used in the present invention are not particularly limited and may be those conventionally known as a packing material for chromatography, and usually have an average particle size of 3 to 3 obtained by a neutralization reaction of alkali silicate. Fifty
Examples include 0 μm spherical and crushed silica gel. The physical properties of silica gel particles include, for example, a pore volume of 0.2 to 2.0 ml / g and a specific surface area of 10 to 800.
Preferred are those having m ² / g and further having an average pore diameter of 10,000 angstroms or less.

In the present invention, the silica gel particles previously treated with an aqueous solution of a magnesium compound are used as the filler.
Examples thereof include water-soluble magnesium compounds such as magnesium chloride and magnesium nitrate, and magnesium chloride is particularly preferable. If the pH value of the magnesium solution is low, the binding of magnesium to the silica gel particles is not performed efficiently, so normally the pH of the aqueous solution is 5.5 or more,
It is desirable to adjust the concentration by adding an alkali such as sodium hydroxide, calcium hydroxide or aqueous ammonia to a concentration of preferably 6 to 10. In particular, ammonia water is desirable because it can be easily removed by drying after the treatment. The pH can control the magnesium content in the finally obtained silica gel.

The contact treatment between the silica gel particles and the magnesium compound aqueous solution can usually be carried out by immersing the silica gel particles in the aqueous solution. The treatment temperature at this time is usually about 5 to 50 ° C., and the treatment time is about 5 to 120 minutes. Note that this contact treatment can also be carried out in the form of a packed tower in which the aqueous solution is passed through a packed bed of silica gel. The silica gel particles after the contact treatment are, if necessary, washed with water and / or alcohol such as methanol, and then dried. The drying temperature is usually about 100 to 150 ° C., and this drying usually causes magnesium to become magnesia and bond to the surface of the silica gel particles. After drying, it may be further baked at 400 ° C. or higher, preferably 550 ° C. or higher.

Thus, the silica gel particles of the present invention coated with the magnesium component can be obtained. Since the silica gel particles of the present invention obtained here can suppress the ion exchange bond with the basic substance, when the silica gel particles are used as a packing material for chromatographic separation, the basic compound can be well separated. . The calcined product can also separate coexisting acidic substances. The magnesium content in the silica gel particles is preferably as high as possible in order to achieve the object of the present invention, but usually the pH of the silica gel particles after the treatment (pH of the aqueous phase in the case of 5% water slurry) is 7.
The amount is preferably 0 or more, and more preferably 7.5 or more. The magnesium content of the silica particles is usually
200 ppm or more, preferably 500 to 5000 ppm
Are preferred.

The packing material for chromatographic separation of the present invention can be used according to a conventional method, for example, as a packing material for high performance liquid chromatography or other packing material for chromatographic separation. Then, it can be applied to analysis or separation and purification of various compounds. In particular, the filler of the present invention is, for example,
It is possible to perform effective adsorptive separation even for basic compounds such as amines, and it is possible to perform highly accurate analysis or efficient separation and purification of a solute containing a plurality of amines.

[0011]

EXAMPLES Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to the description of the following examples as long as the gist thereof is not exceeded. Examples 1, 2, 3 [Production Method] 10 g of silica gel for HPLC (Super Microbeads 100 angstrom, 10 μm) was immersed in 100 ml of distilled water to which 2.5 g of magnesium chloride (MgCl ₂ .6H ₂ O) was added, and this slurry was prepared. While stirring at room temperature, 6N ammonium water was slowly added to adjust the pH to the value shown in Table 1, and after holding it for 30 minutes, suction filtration was performed to collect silica gel. Next, the recovered silica gel was washed successively with 100 ml of distilled water and 100 ml of methanol and then dried at a temperature of 110 ° C. to obtain the silica gel of the present invention.

For each spherical silica gel obtained here, the Mg content (hydrofluoric acid treatment-quantification by atomic absorption spectrometry)
Table 1 shows the results of measurement of physical properties such as pH in the case of using 5% water slurry. Example 4 The pH at the time of immersion was maintained at 9.0, and after the drying treatment, 600
Silica gel was obtained in the same manner as in Example 1 except that calcination was performed for 2 hours.

[0013]

[Table 1]

[Chromatographic Separation Test] Using a high performance liquid chromatography column packed with each spherical silica gel obtained by the above-mentioned treatment, a sample consisting of benzene, dimethyl phthalate and pyridine was tested for normal phase high performance liquid chromatography separation characteristics under the following conditions. When the test was conducted,
The respective peaks as shown in 3 and 5 were obtained, and the peak 1 was benzene, the peak 2 was dimethyl phthalate, the peak 3 was pyridine, and the peak 4 was phenol. .

Column: 4.6φ × 250 mm (stainless steel) Mobile phase: 1% methanol / n-hexane Flow rate: 1 ml / min Detection: UV254 nm The K ′ value of pyridine, the number of theoretical plates, and the symmetry were obtained. It shows in Table 2.

[0016]

[Table 2]

Comparative Example 1 In Example 1, the same sample was tested for normal phase high performance liquid chromatographic separation characteristics under the same conditions using a high performance liquid chromatography column packed with non-magnesium treated spherical silica gel. The peak shown in FIG. 4 was obtained, and peak 3 or pyridine was not eluted.

[0018]

According to the packing material for chromatography of the present invention, the surface of silica gel particles is coated with magnesia. Even if the solute contains a basic compound, the adsorption of these basic compounds The separation can be performed well. Therefore, it is possible to analyze a basic compound with high accuracy, and it is possible to realize more efficient separation and purification.

[Brief description of drawings]

1 shows separation peaks in a normal phase high performance liquid chromatographic separation characteristic test of Example 1. FIG.

FIG. 2 shows separation peaks in a normal phase high performance liquid chromatography separation characteristic test of Example 2.

FIG. 3 shows separation peaks in a normal phase high performance liquid chromatography separation characteristic test of Example 3.

FIG. 4 shows separation peaks in a normal phase high performance liquid chromatography separation characteristic test of Comparative Example 1.

FIG. 5 shows separation peaks in a normal phase high performance liquid chromatography separation characteristic test of Example 4.

[Explanation of symbols]

1 ... benzene, 2 ... dimethyl phthalate, 3 ... pyridine,
4 ... phenol

Claims (2)

(57) [Claims] 1. A packing material for chromatographic separation, characterized by comprising silica gel particles obtained by immersing silica gel in an aqueous solution of magnesium salt, adjusting and maintaining the pH to 5.5 or more, separating and drying the silica gel. 2. The packing material for chromatographic separation according to claim 1, which comprises silica gel particles obtained by further drying and then calcining.