JPH06331618A - Analyzing method for agricultural chemical - Google Patents

Abstract

PURPOSE:To analyze nine components of agricultural chemicals simply and rapidly at once by making analysis with isochrotec elution using a cyanopropyl- group combined type filter. CONSTITUTION:Cyanopropyl-group combined type fillers are those in which a cyanopropyl group is combined to a base such as silica gel, porous polymer gel, etc. When silica gel is used as a base, for example, it is particularly desirable to use cyanoproply-group combined silica gel with carbon rate of 7 to 14% which is synthesized from a highly pure material with extremely low metal contents in favorable material values such as grain diameter, specific surface area, etc. A solution made of organic solvent and a buffer solution is used for a moving phase in isochrotec elution, and methanol, etc., is favorable of the organic solvent and potassium phosphate, etc., for the buffer solution. By this, nine components of agricultural chemicals of asulum, oxine copper mecoprop, thiuram, siduron, iprodion chlorothalonil, pencycuron, and bensylide can be analyzed simply and rapidly at once.

Description

Detailed Description of the Invention

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for analyzing various kinds of pesticides by high performance liquid chromatography (hereinafter abbreviated as HPLC).

[0002]

Agricultural chemicals used in golf courses (ashram, oxine copper, mecoprop, thiuram,
Gas chromatographic method and HPLC method are adopted as the clean water test method for investigating the residue of water pollutants such as ciduron, iprodione, chlorothalonil, penciclone, benzuride, etc.) in the water supply. The analysis of thiuram is carried out by the HPLC method.

The above-mentioned 3 by the HPLC method using a reverse phase C18 packing material.
Although it is possible to analyze the components, for example, in order to perform simultaneous analysis of highly polar ashram, oxine copper, etc. and low polar pencicone, benzlide, etc., it is necessary to use gradient elution, and the condition setting for that is Due to the complexity, there is a limit to the ease and speed of analysis, and there is a strong demand for a simple and speedy analysis method for the 9 components of the pesticides as described above.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above situation, and an object of the present invention is to provide a method for simultaneous analysis of pesticides, which enables simple and rapid analysis of 9 components of pesticides by an HPLC method.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention relates to a method for analyzing agricultural chemicals by high performance liquid chromatography, wherein a cyanopropyl group-bonding type packing material is used as the packing material, and the analysis is carried out by isocratic elution. , At least one of copper, oxine, mecoprop, thiuram, ciduron, iprodione, chlorothalonil, penciclone and benzlide.

[0006] That is, the inventors of the present invention conveniently used 9 components of a wide variety of pesticides having large polar differences, specifically, ashram, oxine copper, mecoprop, thiuram, ciduron, iprodione, chlorothalonil, pencyclone and benzlide, by an HPLC method. As a result of earnest research to develop a method for simultaneous simultaneous analysis, if a packing material having a cyanopropyl group is used as the packing material, it is possible to easily perform isocratic elution.
They found that rapid HPLC analysis was possible and completed the present invention.

Examples of the cyanopropyl group-bonding type filler used in the present invention include those in which a cyanopropyl group is bonded to a base material such as silica gel, porous polymer gel (alkylated polyvinyl alcohol type, methacrylic acid ester type, etc.). Is mentioned. The preferred physical properties of the base material that is the raw material of the filler according to the present invention differ depending on the type of the base material. For example, when silica gel is used as the raw material base material, the physical property value of the raw material silica gel is as follows: particle size: 3 ~ 10 μm,
Preferably 4 to 7 μm, specific surface area: 300 to 700 m ² / gr, preferably 450 to 600 m ² / gr, pore volume: 0.6 to 1.2 ml / gr,
Desirably, 0.8 to 1.0 ml / gr and a pore diameter of 50 to 200 angstroms, preferably about 100 angstroms are desirable, and the filler according to the present invention has, for example, such physical properties. A particularly preferable filler is a cyanopropyl group-bonded silica gel having a carbon ratio of 7 to 14%, which is synthesized from a high-purity product having an extremely low metal content.

The method for producing the cyanopropyl group-bonding type filler will be described below by taking the case of using silica gel as a raw material base material as an example. That is, pore size 100 angstrom
Spherical silica gel having an average particle size of 4 to 7 μm is mixed with toluene, dried pyridine and 3-cyanopropyldimethylchlorosilane under stirring for 6 to 10 hours, and then reacted by heating, refluxing. After allowing to cool, it is filtered, and the residue is washed with toluene, methanol, water, methanol, and acetone in this order, and then dried. After that, the dried gel is subjected to a conventional method, for example, 6
The target cyanopropyl group-bonded filler can be easily obtained by subjecting the mixture to endcapping by heating for 10 hours or the like.

As the mobile phase in the isocratic elution according to the present invention, a solution consisting of an organic solvent and a buffer solution is used. As the organic solvent used for this, a solvent which does not have UV absorption in the low wavelength region and which is used in reverse phase conditions and which has high polarity, such as methanol and acetonitrile, is usually used. In general, acetonitrile is preferably used because acetonitrile is used for extracting the sample for analysis.

The amount of the organic solvent used in the mobile phase is not particularly limited as long as the concentration in the buffer solution is 20 to 80 V / V%.

The type of buffer used in the mobile phase is
There is no particular limitation as long as it has no UV absorption in the low wavelength region, but potassium phosphate, sodium phosphate, etc. are usually preferably used. The salt concentration as the buffer solution is usually in the range of 10 to 500 mM, but a concentration of 10 to 100 mM is preferable in consideration of maintenance of the HPLC device, column life and the like.

The pH range of the mobile phase is not particularly limited as long as it can analyze the target pesticide, but pH 2.0 to 7.0 is preferable considering the column life and the like.

When the above-mentioned 9 components of the agricultural chemical are simultaneously analyzed, it is desirable to set the pH within the range of 3.6 to 3.9 in order to maintain the analysis accuracy of ashram, oxine copper and mecoprop.

Needless to say, the mobile phase may contain a chelating agent such as EDTA, if necessary, in addition to the organic solvent and the buffer solution.

In the present invention, the flow rate during elution is usually 0.
3 to 2.0 ml / min, preferably 0.7 to 1.3 ml / min, and the column temperature is usually 20 to 60 ° C, preferably 30 to 40 ° C.

The analysis method of the present invention can be carried out, for example, as follows. That is, an analytical column filled with a cyanopropyl group-bonding type packing material was attached to an HPLC apparatus, equilibrated with a mobile phase, and then a pretreated sample was injected and
Isocratic elution under conditions of 0.3 to 2.0 ml / min and column temperature of 20 to 60 ° C will allow simultaneous and rapid simultaneous and rapid mixing of ashram, oxine copper, mecoprop, thiuram, ciduron, iprodione, chlorothalonil, penciclone and benzlide. Can be analyzed.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited thereto.

[0018]

【Example】

Example 1 (filler) silica gel (pore size 100 angstrom,
Toluene 2 to 10 g of spherical silica gel having an average particle diameter of 5 μm
Add 20 ml, stir, heat, and toluene-water azeotrope 70 m
l was distilled off. To this, 10 ml of dry pyridine and 6.0 g of 3-cyanopropyldimethylchlorosilane were added, and the mixture was heated under reflux for 8 hours with stirring. After cooling, the reaction solution was filtered and the residue was washed 3 times with 20 ml of toluene. Then methanol,
Washing was repeated in the order of water, methanol and acetone, and drying was performed to obtain 10.8 g of cyanopropyl silica gel. To 8 g of the above silica gel, 40 ml of dry toluene and 9 ml of hexamethyldisilazane were added, and the mixture was heated and reacted for 8 hours. After cooling, the residue was washed with toluene, methanol, water, methanol, and acetone in this order, and dried to obtain 8 g of a cyanopropyl group-bonded filler.

(Sample) (A) Standard Solution 1 Using pesticide standard products, ashram: 5 μg / ml, oxine copper: 5 μg / ml, mecoprop: 10 μg / ml, thiuram: 10
μg / ml, siduron: 10 μg / ml, iprodione: 10 μg /
ml :, Chlorothalonil: 5 μg / ml, Penciclone: 10 μg
/ ml, and benzlide: 10 μg / ml were dissolved in acetonitrile to prepare. (B) River water solid-phase extract liquid 500 ml of river water was adjusted to pH 4.0 by adding 0.1N nitric acid.
This was applied to a solid phase column (SPE-GLF Yokogawa Analytical Systems Co., Ltd .; washed with 5 ml of acetonitrile and 10 ml of distilled water) at a flow rate of 10 to 20 ml / min by vacuum suction. Then, extraction was carried out from the solid phase column with 5 ml of acetonitrile to obtain a river water solid phase extract. (C) Standard solution-added river water solid phase extract solution 500 ml of river water was adjusted to pH 4.0 with 0.1N nitric acid, and 5 ml of standard solution 1 from (A) above was added, as in (B) above. Was treated and extracted to obtain a river water solid phase extract containing standard solution.

(Procedure) A cyanopropyl group-bonding type packing material was slurry-filled in a 4.6φ × 150 mm stainless steel column (manufactured by Sugiyama Shoji Co., Ltd.), set in an HPLC apparatus and analyzed under the following analytical conditions. Analysis conditions Mobile phase: 50 mM monopotassium phosphate and 50 mM phosphoric acid 1000: 22
(V / V) mixed buffer solution (pH 3.8) and acetonitrile at a ratio of 59:41 (V / V), EDT
What added A * 2Na so that it might become 100 mg / l was made into the mobile phase. Flow rate: 1.0 ml / min (pump; LC-6A Shimadzu Corporation)
Column temperature: 35 ° C (column oven; CTO-6A, manufactured by Shimadzu Corporation) Detection: UV absorption wavelength of each component Maximum absorption wavelength within 230 to 270 nm (detector; MCPD-3600, manufactured by Otsuka Electronics Co., Ltd.) ) Sample injection volume: 10 μl

(Results) The results obtained are shown in FIG. still,
Each peak number in FIG. 1 shows the following 9 pesticide components. 1: ashram, 2: oxine copper, 3: mecoprop, 4: thiuram, 5: siduron, 6: iprodione, 7: chlorothalonil, 8: penciclone, 9: benzlide. From the results of (A) in Fig. 1, when standard solution 1 was used as a sample, complete separation analysis of 9 components of ashram, oxine copper, mecoprop, thiuram, ciduron, iprodione, chlorothalonil, penciclone and benzlide within 25 minutes was possible. From the results of FIGS. 1 (B) and 1 (C), it is understood that complete separation analysis of the above 9 components contained in river water is possible.

Example 2 (Filler) The same as that obtained in Example 1.

(Sample) (A) Standard Solution 1 Same as that used in Example 1. (B) Standard solution 2 Using pesticide standard products, ashram: 5 μg / ml, oxine copper: 5 μg / ml, mecoprop: 10 μg / ml, thiuram: 10
μg / ml, iprodione: 10 μg / ml, pencyclone: 10 μ
g / ml and benzlide: Prepared by dissolving in acetonitrile so as to be 10 μg / ml.

(Procedure) The pH of the buffer solution is adjusted to 2.0 to by changing the mixing ratio of 50 mM monopotassium phosphate and 50 mM phosphoric acid.
What was changed by 0.5 in the range of 7.0 was used as the buffer solution for the mobile phase, and other than that, under exactly the same conditions as in Example 1,
The standard solution 1 (9 components of agricultural chemicals) was simultaneously analyzed by the same operation as in Example 1. Further, the standard solution 2 (7 components of agricultural chemicals) was simultaneously analyzed in the same manner as above using the mobile phase in which the pH was changed by 0.1 in the range of 3.4 to 4.4.

(Results) The obtained results are shown in FIGS. The symbols in FIGS. 2 and 3 indicate the following 9 pesticide components, respectively. Ben. : Benthuride, Pen. : Penciclone, Chl. : Chlorothalonil, Ipr. : Iprodione, Si-1: siduron-1, Si-2: siduron-2 (isomer of siduron-1), Thi. :
Thiuram, 8-qu: oxine copper, MCPP: mecoprop, Asu. : Ashram. As is clear from the results of FIG. 2, oxine copper and mecoprop are easily affected by the pH of the mobile phase, and when the pH is low, the retention of oxine copper tends to be small and the retention of mecoprop tends to be large, and pH 4. If it is higher than 5, it can be seen that the retention of ashram is also small and it does not separate sufficiently from Mecoprop. Further, as is apparent from the results of FIG. 3, it is understood that it is preferable to carry out the analysis in the pH range of 3.7 to 3.8 in order to accurately separate and analyze ashram, oxine copper and mecoprop which are easily influenced by pH.

Example 3 (Filler) The same as that obtained in Example 1.

(Sample) The standard solution 1 prepared in Example 1 was used.

(Operating method) The detection wavelengths for determining the peak area and the peak height were as follows: Ashram: UV 270 nm, Oxine copper: UV 240 nm, Mecoprop, Thiuram, Siduron, Iprodione, Chlorothalonil, Penciclone and Bencelide: UV 230 nm. Except for the above, the same column and the same apparatus as in Example 1 were used, and repeated analysis (n = 11) was performed in the same manner as in Example 1 to examine the reproducibility of elution time, peak area, and peak height. It was

(Results) The results obtained are shown in Table 1.

[0030]

[Table 1]

As is clear from the results in Table 1, the obtained coefficient of variation (CV) is 0.13% or less for the holding time, 1.9% or less for the peak area, and 2.6% or less for the peak height. It can be seen that the reproducibility of the analysis method of 1 is good.

Example 4 (Filler) The same as that obtained in Example 1.

(Sample) (A) Using a pesticide standard, ashlide, oxine copper, mecoprop, thiuram, ciduron, iprodione, chlorothalonil and penciclone were adjusted to 5 μg / ml to 100 μg / ml and benzlide was 10 μg. It was dissolved in acetonitrile so as to have a concentration of / ml to 100 µg / ml.

(Operation method) The detection wavelength for obtaining the peak area was as follows: Ashram: UV 270 nm, Oxine copper: UV240n.
m, mecoprop, thiuram, ciduron, iprodione, chlorothalonil, penciclone and benzlide: UV
Using the same column and the same equipment as in Example 1 except that the thickness was 230 nm, the same operation as in Example 1 was carried out to obtain the pesticide concentration (μ
(g / ml) and the peak area (absorbance / min), and a calibration curve showing the relationship between them was obtained.

(Results) The results obtained are shown in FIG. 4 and Table 2. The symbols in FIG. 4 (A) are the following pesticides 4 respectively.
The ingredients are shown. □: Ashram, +: Oxine copper, △: Thiuram, ×:
Chlorothalonil. In addition, each symbol in FIG. 4B indicates the following five pesticide components. □: Iprodione, +: Pencicloone, ◇: Benthlide, Δ: Siduron, ×: Mecoprop.

[0036]

[Table 2]

As is clear from the results shown in Table 2 and FIG. 4, the calibration curves for ashram, oxine copper, mecoprop, thiuram, cidurone, iprodione, chlorothalonil, penciclone and benzlide are all straight lines passing through the origin with a correlation coefficient of 0.999. It can be seen that it is excellent in quantification.

[0038]

INDUSTRIAL APPLICABILITY The present invention provides a simple and rapid simultaneous analysis method for ashram, oxine copper, mecoprop, thiuram, ciduron, iprodione, chlorothalonil, penciclone and benzlide, which were difficult to perform simultaneous analysis by the conventional method. This is a great invention that contributes to the industry.

[0039]

[Brief description of drawings]

1 shows the chromatogram obtained in Example 1. FIG.

FIG. 2 shows the pH (p (p) of the mobile phase obtained in Example 2).
It is a graph which shows the relationship between H2.0-7.0) and holding time.

FIG. 3 shows the pH of the mobile phase (p (p) obtained in Example 2).
It is a graph which shows the relationship between H3.4-4.4) and holding time.

FIG. 4 shows a calibration curve obtained in Example 4.

[0040]

[Explanation of symbols]

FIG. 1 shows 1: ashram, 2: oxine copper, 3: mecoprop, 4: thiuram, 5: cydurone, 6: iprodione, 7: chlorothalonil, 8: pentylcone, 9: benzlide in FIG.

FIG. 2 shows that in FIG. : Benthuride, Pe
n. : Penciclone, Chl. : Chlorothalonil, Ip
r. : Iprodione, Si-1: Siduron-1, Si
-2: siduron-2 (isomer of siduron-1),
Thi. : Thiuram, 8-qu: oxine copper, MCP
P: Mecoprop, Asu. : Indicates ashram.

FIG. 3 shows the results of Ben. : Benthuride, Pe
n. : Penciclone, Ipr. : Iprodione, Th
i. : Thiuram, 8-qu: oxine copper, MCPP:
Mecoprop, Asu. : Indicates ashram.

FIG. 4 (A) shows □: ashram, +: oxine copper, Δ: thiuram, ×: chlorothalonil. In FIG. 4 (B), □: iprodione, +: pensciron, ⋄: bensulide, Δ: siduron, x: mecoprop.

Claims (1)

[Claims] 1. A method for analyzing agricultural chemicals by high performance liquid chromatography, wherein a cyanopropyl group-bonding type packing material is used as the packing material, and the analysis is carried out by isocratic elution, ashram, oxine copper, An analysis method of at least one of mecoprop, thiuram, ciduron, iprodione, chlorothalonil, penciclone and benzlide. [0001]