JPS6290534A - Polymer filter for high performance liquid chromatography - Google Patents

Abstract

PURPOSE:To separate many kinds of hydrocarbons each having an aliphatic chain and derivatives thereof with high accuracy on the basis of the difference between hydrophobic constants without generating specific adsorption, by allowing a predetermined polymer gel high-molecular filler with a specific particle size obtained by the suspension polymerization of predetermined mechacrylate and a crosslinking agent in a predetermined ratio to satisfy a predetermined condition. CONSTITUTION:Methacrylate represented by general formula I (wherein R is a 8-24C alkyl group) and a crosslinking agent are subjected to suspension polymerization in a volumetric ratio of 1:0.3-5 to obtain a polymer gel with a particle size of 2-20mum and this polymer gel is uses as a filler for high performance liquid chromatography. As the crosslinking agent, an aromatic polyvinyl monomer or an acrylic acid type polyvinyl monomer is used. By allowing said filler to satisfy log K'=y X log P + m (wherein K' is the holding ratio of a specimen, log P is a hydrophobicity constant and y and m are a constant), good separation can be performed regardless of the polarity of the specimen on the basis of the difference between the hydrophobicity constants of components to be separated.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a polymer packing material for high performance liquid chromatography, and more particularly to a packing material for high performance liquid chromatography comprising a methacrylate polymer gel.

<Prior Art and Problems> Conventionally, as liquid chromatography, reverse phase partition liquid chromatography, which separates samples based on differences in their hydrophobic constants (log P), has been known. Generally, when separating samples by reverse phase partition liquid chromatography, examples of the packing material used include coated column packing materials and chemically bonded column packing materials.

Currently applied coated column packing materials include silica gel, alumina, and diatomaceous earth as fixed substances, such as β, β'-oxydipropionitrile, carbowax, ethylene glycol, trimethylene glycol, cyanoethyl silicone, and hydrocarbon polymers. Chemically bonded column packing materials are generally covalently bonded to the silanol groups (Si-OH) on the silica surface, and are coated with polyethylene glycol, octadecylsilane, or octadecyltrichlorosilane as the stationary phase. , diphenyldichlorosilane, quaternary alkylamine, oxypropionitrile, etc. are used. A silica gel packing material having octadecyl groups bonded thereto is called ODS silica and is generally used in liquid chromatography.

Coated column packing materials have the disadvantage that the stationary phase coated on the silica gel surface dissolves depending on the type of mobile phase eluent, causing the coating phase to peel off and elute. On the other hand, chemically bonded column packing materials are chemically bonded to silanol groups in order to compensate for the drawbacks of the former, but the chemically bonded Si-〇-C type bonds are used in halogen-containing solvents such as CH(1, etc.), acetone, etc. These can be used as eluents because they are cleaved by
H is also limited to 2 to 8, which has the disadvantage that it cannot be used in all pH ranges.

Furthermore, it is difficult to chemically bond all the silanol groups on the silica surface, and some unreacted silanol groups remain, which may cause specific adsorption for some types of samples, resulting in a change in the hydrophobicity constant (log It was not possible to separate them only due to the difference in P).

Furthermore, in the case of separation using ODS silica, there is also an influence due to residual silanol groups. ODS silica generally uses a highly polar water-methanol mixture or water-acetonitrile mixture as the eluent, but there are other problems with its use, such as the fact that many samples do not dissolve in the mixture.

It has various drawbacks, such as a short retention time for substances with a small hydrophobic constant (log P), making it impossible to separate them.

<Object of the invention> The object of the present invention is to avoid specific adsorption and to maintain the hydrophobicity constant (l) of the sample.
An object of the present invention is to provide a polymer packing material for high performance liquid chromatography that can separate various types of hydrocarbons having aliphatic chains and their derivatives with high precision due to differences in og P).

According to the present invention, a methacrylate represented by the following general formula (1) % formula % (1) (wherein R represents an alkyl group having 8 to 24 carbon atoms) and the crosslinking agent at a volume ratio of 1
: Particle size obtained by suspension polymerization in the range of 0.3 to 5.
A polymeric filler consisting of a 20μ polymer gel,
The filler is expressed by the following formula 1% (where log K' is the logarithm of the retention ratio of the sample, log
A polymer packing material for high performance liquid chromatography is provided, which is characterized by having a property satisfying the following: g P is a hydrophobic constant, and y and m are constants.

The present invention will be explained in more detail below.

In the present invention, carbon number 8 to 24 represented by the above general formula (1) is used.
A polymer gel obtained by turbidity polymerization of a methacrylate having an alkyl group and a crosslinking agent is used. If the number of carbon atoms in the alkyl group, which is the ester group of methacrylate, is 7 or less, the separation accuracy will be poor, while if it is 25 or more, synthesis will be difficult and it is not suitable for practical use. As the crosslinking agent, aromatic polyvinyl monomers or acrylic acid-based polyvinyl monomers can be used, and specifically, divinylbenzene, divinyltoluene, divinylxylene, divinylpyridine, trivinylbenzene, diallylphthalate, diallyl acrylate, and ethylene. Glycol dimethacrylate, trimethylolpropane trimethacrylate,
Examples include pentaerythritol tetramethacrylate. Alternatively, a part of the methacrylate represented by the above general formula (1), for example, about 10 to 80 parts by weight per 100 parts by weight of methacrylate, may be replaced with a monovinyl compound such as a styrene-based aromatic compound or an acrylic acid-based aliphatic compound. good. Examples of the styrene-based aromatic compounds include styrene, ethylstyrene, vinylnaphthalene, etc., and examples of the acrylic acid-based aliphatic compounds include acrylic esters, methacrylic esters, and the like.

The mixing ratio of methacrylate and crosslinking agent is methacrylate:crosslinking agent in a volume ratio of 1:0.3 to 5, preferably 1:
: 0.4-2. If the crosslinking agent content is less than 0.3, the mechanical strength of the filler will decrease, while if it exceeds 5, the holding force of the sample will decrease. Polymerization is carried out in water using polyvinyl alcohol or the like as a dispersion stabilizer to carry out S-turbid polymerization. As a polymerization initiator, organic peroxides such as benzoyl peroxide, butyl peroxide, succinic peroxide, butyl hydroxy peroxide, 2,2'-acyhis (2
, 4-dimethylvaleronitrile), azobisisobutyronitrile, etc. can be used. In polymerization, diluents that are not reactive with methacrylates and crosslinking agents and are compatible with them, such as toluene, xylene, chlorobenzene, dichlorobenzene, chloroform, acetone, and ethyl acetate, may be used. as an agent.

For example, paraffins, higher alcohols, natural oils and fats,
Low gravity linear polymers and their halogen compounds, or halogen compounds, aromatic solvents, and these halogen compounds may be added as a swelling agent using a high boiling point organic solvent. Polymerization is usually carried out at a temperature of 25 to 100°C for about 1 to 20 hours.

In the present invention, a polymer gel having a particle size of 2 to 20 microns, preferably 3 to 10 microns is used. If it exceeds 20μ, the separation accuracy deteriorates and it cannot be used. Furthermore, if a particle less than 2μ is used, it will take time to separate it.

Note that the particle size of polymer gel refers to the volume average particle size. To obtain a polymer gel with a particle size of 20μ or less, it is necessary to increase the amount of surfactant added, to polymerize at a relatively high temperature, or to increase the speed during the reaction. Stir thoroughly.

You may use these together.

The polymer packing material for high performance liquid chromatography of the present invention obtained in this manner has the following formula 1% (wherein 1 formula gK' is the logarithm of the retention ratio of the sample, lo
g P is a hydrophobic constant, y and m are constants). The constants y and m are constants determined by the eluent and the measurement temperature. The hydrophobic constant (log
P) is the Hansch method (A, Leo, P, V, C, J
ov.

C, 5ilipo, and C, Hansch, J.
Meol, Che+n, 18, 856 (1975)) and represents the degree of hydrophilicity and lipophilicity of the sample. The hydrophobicity constant (logP) is the retention ratio of the sample (
k'). Specifically, the retention ratio (k') is calculated from the sample elution time (tr) and the solvent elution time (to), and is expressed as k' = (tr-t o)/t, o. If there is no specific adsorption of the sample, the logarithm of the retention ratio (log k') and the hydrophobic constant of the sample (log P) are expressed as (log k') = y X (log P)
+m holds true, and in order to obtain good separation, y
The larger the value of m, the more suitable the separation becomes possible with a slight difference in the (log P) value, and the larger the value of m is, the more suitable the separation becomes possible with a small difference in the (log P) value.

According to the packing material of the present invention, good separation can be performed regardless of the polarity of the sample, and it is also possible to estimate the polarity of the sample from the elution time.

In the present invention, the polymer gel obtained as described above is used as a packing material for high performance liquid chromatography. As a method for filling the column with the packing material, there are known methods that allow control of the packing rate, such as "filling material".
(Edited by Tsutomu Hashimoto, Musashino Livestock), the balanced slurry method,
It goes without saying that no matter what filling method is used, such as a simple slurry method or a high viscosity slurry method, sufficient consideration should be given to uniform filling of the filler.

<Effects of the Invention> According to the separation method of the present invention, various aliphatic hydrocarbons and their derivatives, such as fatty acids and their esters, alcohols, diols, alkylbenzenes, etc., can be removed without specific adsorption and with the hydrophobicity constant (log P) of the sample being reduced. The difference allows for accurate separation and experimental analysis.

It can be widely used for industrial separation and purification.

<Examples> The present invention will be specifically explained below with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples.

111- Put 3.6 g of polyvinyl alcohol dissolved in 600 mQ of water into an IQ flask, and add various methacrylic esters (
For each 40 mQ of methyl methacrylate, butyl methacrylate, octyl methacrylate, 40 mQ of ethylene glycol dimethacrylate, and 6 toluene as a diluent.
Add 0 mQ, 2.0 g of 2,2-isobutylvaleronitrile to prepare a homogeneous mixture, place the flask containing this in an ice water bath, and cool the flask while keeping the internal temperature below 20°C. First, the polymerization solution inside was stirred at high speed with a high-speed stirrer.Then, the flask was placed in a water bath kept at 80℃, and the flask was heated to 80℃ while stirring with a boat-shaped stirring rod to keep the temperature inside the flask uniform. After 10 hours of polymerization, the resulting gel was washed with hot water and acetone, and the volume average particle size of the gel was reduced to 5.0 to 5.0 by decantation with acetone.
I adjusted it to 7.5μ.

Column (4, 5
After filling mφX25aa, stainless steel).

Samples with different hydrophobic constants (log P) (1, benzene, 2, toluene; 3. ethylbenzene; 4. n-propylbenzene; 5. n-butylbenzene; 6°5aC-butylbenzene; 7, tert-butylbenzene; 8
．． n-hexane; 9. n-hebutane; 10° n-octane; 11. n-nonane; 12. n-decane; 13. n-
Undecane; 14. Methyl n-caproate; 15. n-
Methyl caprylate; 16゜n-methyl caprate; 17
．． Methyl laurate; 18, methyl myristate; 19
．． Methyl balmitate; 20. Phenol; 21. Acetophenone; 22. The retention ratio (k') of methyl benzoate was measured by reverse phase partition liquid chromatography using methanol as an eluent. Figure 1 (a) shows a polymer gel (MMA-EDM) of methyl methacrylate (MMA) and ethylene glycol dimethacrylate (EDMA).
A) The hydrophobicity constant (lo
g P) (horizontal axis) and the retention ratio is the logarithm of '(log k
) (vertical axis) is shown in the graph. Similarly, the first
Figure (b) shows the case where a polymer gel (BMA-EDMA) of butyl methacrylate (HMA) and ethylene glycol dimethacrylate (EDMA) is used;
A polymer gel of octyl methacrylate (OMA) and ethylene glycol dimethacrylate (EDMA) (
As shown in FIGS. 1(a) and 1(b), which respectively show similar relationships when using OMA-EDMA).

Three straight lines are observed in polymer gels using methacrylates in which the alkyl group (ester group) has 1 (MMA) and 4 (BMA) carbon atoms, and log k' = y x
There are three types of relationships of (log P)+m, and specific adsorption due to functional groups is observed, indicating that separation cannot be achieved solely based on sample polarity. On the other hand, in Figure 1 (c), the polymer gel of the present invention using methacrylate having 8 carbon atoms is used, and a linear relationship is observed between (log P) and (log k'). and the hydrophobicity constant (log
P) shows that the sample can be separated.

The volume ratio of stearyl methacrylate (SMA) and ethylene glycol dimethacrylate (EDMA) is SMA.
/EDMA=0.5, 1.0, 2.0, respectively, in the same manner as in Example 1, except that the volume average particle size was 5. O~7.5μ
(7) Polymer gel/L/(-SMA-EDMA) was prepared.

Retention ratio (K') was determined by reverse phase partition liquid chromatography using methanol as an eluent for the same sample as in Example 1.
was measured.

Figure 2 (a) shows that when SMA/EDMA=0.5,
In Figure 2 (b), SMA/EDMA = 1.0, Figure 2 (
C) shows a graph similar to Example 1 showing the relationship between the logarithm (log K') of the retention ratio and (logP) in each case of SMA/EDMA=2.0. In either case (l
A linear relationship is observed between og' P ) and (log K'), and the hydrophobic constant of the sample (log P
) shows that it is possible to separate the sample. Furthermore, for the same eluent, as the blending ratio of SMA increases, the values of y and m tend to increase, indicating that the eluent is particularly suitable for separation.

The same polymer gel as in Example 2 (SMA/EDMA=1
), saturated fatty acids CH, (CH-)n-zC○OH
(n = 6.8, 10, 12, 14.16) and a known ODS silica gel, using methanol as an eluent according to Example 1, the hydrophobic constant (log P) and the retention ratio were determined by the logarithm of '( log k') was investigated. FIG. 3 shows a comparison between the use of the filler of the present invention and ODS silica gel.

As is clear from FIG. 3, in the filler of the present invention, m=-
0,762 was obtained, known filler (m=-1,259)
The value of m is large compared to the hydrophobic constant (log P)
It can be seen that this method is suitable for separating objects with small values.

Last 7Jf! (fl14, SMA/EDMA obtained in Example 2 = 1.0
using methanol/water (
The retention ratio (K') was measured in the same manner as in Example 2, except that a volume ratio of 9/1 was used.

Based on the results, a graph showing the same relationship as in Figure 1 was created in Figure 4.
As shown in the figure. As is clear from Figure 4, (log P)
A linear relationship is observed between and (log K'), indicating that the sample can be separated by the hydrophobic constant of the sample even in this eluent.

[Brief explanation of drawings]

Figures 1 (a) to (c) are graphs showing the relationship between the hydrophobic constant and the logarithm of the retention ratio of samples when using the filler of the present invention according to Example 1 and the filler according to Comparative Example. . Second
Figures (A) to (C) are graphs showing the same relationships as in Figure 1 when the filler of the present invention according to Example 2 is used, and Figure 3 is a graph showing the relationship between the filler of the present invention according to Example 3 and a comparative example. FIG. 4 is a graph when the filler of the present invention according to Example 4 is used.

Claims (1)

[Claims] A methacrylate represented by the following general formula (1) ▲ Numerical formula, chemical formula, table, etc. ▼... (1) (In the formula, R represents an alkyl group having 8 to 24 carbon atoms) and the crosslinking agent at a volume ratio of 1
: Particle size obtained by suspension polymerization in the range of 0.3 to 5.
A polymeric filler consisting of a 20μ polymer gel,
The filler has the following formula log K'=y×log P+m (where log K' is the logarithm of the retention ratio K' of the sample, l
og P is a hydrophobic constant, and y and m are constants). A polymer packing material for high performance liquid chromatography.