KR20030078097A - Determination Method of Glyphosate, Endothall and Chloramben in Water Samples - Google Patents

Abstract

PURPOSE: A simultaneous detection method of Glyphosate, Endothall and Chloramben as herbicides in water samples is provided, thereby easily, accurately and cheaply detecting the herbicides at one time. CONSTITUTION: A simultaneous detection method of Glyphosate, Endothall and Chloramben as herbicides in water samples comprises the steps of: concentrating Glyphosate, Endothall and Chloramben and forming their derivatives with anhydrous trifluoroacetic acid and trifluoroethanol; analyzing their derivatives to prepare a measuring curve for determination of the concentrations of three herbicides; forming derivatives of three herbicides in various environmental samples; and determining the concentrations of three herbicides, wherein the concentration is carried out by using vaporization under vacuum; the formation of derivatives of three herbicides is carried out by heating the mixture of herbicides with trifluoroacetic acid and trifluoroethanol at 60 to 90 deg. C for 30 to 120 minutes; and the concentration of three herbicides is determined by using gas chromatography/mass spectrometer.

Description

Determination Method of Glyphosate, Endothall and Chloramben in Water Samples}

The present invention is a detection method for simultaneously detecting three acidic pesticides such as glyphosate, endothall, and chloramben in drinking water and water samples, and vacuum rotating the above three pesticides in more detail. After concentration using an evaporator, trifluoroethanol was reacted with trifluoroacetic anhydride and trifluoroethanol under a constant reaction time and temperature, and then three kinds of pesticides were derivatized, and then directly subjected to gas chromatography (GC) or gas. It relates to a method for acidic pesticides by analyzing using chromatography / mass spectrometry (GC / MS). The method of the present invention has advantages such as excellent sensitivity, shortening and simplicity of analysis time, and economic efficiency, and thus can be effectively applied to monitoring pesticides remaining in trace amounts in water quality.

The three pesticides to be analyzed are widely used as herbicides and have been widely used worldwide because they are relatively inexpensive and can be effective in small amounts (Analytica Chimica Acta 414, 79-84 (2000)). However, it has been reported that after the use of these harmful substances seep into the river, lake, groundwater, soil, etc. after use, it pollutes the environment [J. Agric. Food. Chem., 38, 142 (1990)].

All three substances analyzed in the present invention are glyphosate, endortal and chlorambene. These pesticides have never been analyzed simultaneously. In addition, glyphosate is hardly soluble in a general organic solvent, solubility in water is about 0.012g / ㎖. For this reason, extraction was very difficult. The three substances have a carboxyl group (-COOH) and an amino group (-NH) in the molecule, and thus have a high polarity, and thus have problems in trace analysis when they are analyzed by themselves, or when gas chromatography cannot detect them. There is. For this reason, in order to analyze these pesticides, a method mainly using liquid chromatography or analyzing using diazomethane or diazomethane or PFPH has been used. However, a number of problems have been pointed out, such as disadvantages that these reagents are dangerous to use or are highly toxic. Therefore, there has been a demand for a stable detection method that can be analyzed quickly, economically and in trace amounts.

Accordingly, the present invention enables effective analysis of three herbicides, which are difficult to co-extract, in a water sample, and provides an analytical method having selective and excellent sensitivity to gas chromatography or gas chromatography / mass spectrometer. Improved reproducibility, accuracy, shortened analysis time, low cost and simplicity can be satisfied. As a result, three herbicides, which are harmful to humans, can be analyzed quantitatively at the same time in water samples. The aim is to provide a widely applicable analytical method.

Figure 1 shows the extraction recovery rate according to the extraction solvent and concentration in the present invention.

Figure 2 shows the chromatogram of the three herbicides analyzed by gas chromatography / mass spectrometry in the present invention.

Figure 3 shows the mass spectrum of the three herbicides derivatized in the present invention.

Figure 4 shows the calibration curve for quantification in the present invention.

The present inventors used a method of directly evaporating and concentrating a water sample to effectively analyze three herbicides that are difficult to extract from drinking water and water samples. After concentration, these three materials were derivatized by reacting with trifluoroacetic anhydride and trifluoroethanol, which were then analyzed by direct gas chromatography or gas chromatography / mass spectrometry to analyze trace concentrations of the three herbicides. The detection method became possible.

The present invention will be described in detail as follows.

In the present invention, a method of concentrating to analyze three herbicides from drinking water and water samples is employed. These materials are difficult to extract with a solvent because the extraction rate with respect to the organic solvent is very low. In addition, there are no experimental reports on simultaneous extraction and analysis of these three materials. In the present invention, in order to compensate for this disadvantage, 5-10 ml of water is completely dried using a direct vacuum rotary evaporator without using an organic solvent and then reacted with trifluoroacetic anhydride and trifluoroethanol. All herbicides are derivatized. This derivatization reaction is shown in Scheme 1 below.

In the derivatization process of Scheme 1, the reaction time with trifluoroacetic anhydride and trifluoroethanol of three pesticides is particularly important. The amount of trifluoro anhydrous acetic acid is 50 to 150 μl, preferably 100 μl is suitable, the amount of trifluoroethanol is 25 to 100 μl, preferably 50 μl, and the reaction temperature is 60 to 90 ℃, preferably Preferably 80 ° C is suitable, and the reaction time is 30 to 120 minutes, preferably 60 minutes. When the derivatization reaction is performed under these conditions, the compound represented by Scheme 1 can be obtained. The method is an optimal condition for derivatization of the three herbicides, and provides gas chromatography or gas chromatography / mass spectrometers with better sensitivity and selectivity and better detection limits.

Analysis of the derivatized three acid herbicides is carried out using gas chromatography or gas chromatography / mass spectrometry, specifically injected into gas chromatography and using a gas inert to oxidation as the mobile phase. Gas that can be used as the mobile phase can be any conventional gas used in gas chromatography. Preferably, nitrogen, helium, hydrogen or the like which is inert to oxidation can be used. The length and inner diameter of the column can be used as long as the column has a medium polarity.

Hereinafter, the present invention will be described in more detail based on the following examples, but the present invention is not limited to the following examples.

Example

Example 1

Four blank test tubes were prepared, and 50 μl of 10 μg / ml solution of the three kinds of herbicides were added to each test tube, and 10 μl of 10 μg / ml of 2,4-dichlorophenylacetic acid solution, which is an internal standard. After the addition, 50 μl of methyl iodide, ethyl iodide, and propyl iodide were added to three test tubes of four test tubes, and then 150 μl of acetone was added thereto, and about 2 to 3 mg of potassium carbonate powder was added thereto. It was. In another test tube, trifluoroacetic anhydride and trifluoroethanol were added, and each was reacted at 80 ° C for 1 hour. As a result, three of the above four reactions did not occur, only the reaction with trifluoroacetic anhydride and trifluoroethanol occurred.

Example 2

10 ml of distilled water was put into three 25 ml separating funnels, and 50 µl of 10 µg / ml solutions of three kinds of herbicides were added, and 10 µg / ml of 2,4-dichlorophenylacetic acid solution, an internal standard, was added. Add 10 μl each. 2 g of anhydrous sodium sulfate is added to the two samples for salting effect, 1 part of two funnels are ethyl ether and 5 ml of methylene chloride is added to the other funnel and shaken for 15 minutes. . After removing the water layer after extraction, the extraction solvent is blown off completely. Water was removed from the solvent layer and the two samples were concentrated and 100 µl of trifluoroacetic anhydride and 50 µl of trifluoroethanol were added to the remaining residue, respectively, to enter the derivatization process. One sample that was not subjected to the extraction process was completely dehydrated using a direct rotary vacuum evaporator, followed by derivatization by adding 100 μl of trifluoroacetic anhydride and 50 μl of trifluoroethanol. After heating at 80 ° C. for 1 hour, the reaction was completed, cooled, dried under nitrogen again, the sample was dissolved in 100 μl of ethyl acetate solution, and injected directly into 2 μl of gas chromatography for analysis. In this embodiment, the extraction rate according to the extraction solvent is intended. The results are as shown in FIG. 1 and the extraction using the solvent was hardly performed. Only the direct concentration of the sample using the vacuum rotary evaporator showed good results.

Example 3

2 μl of the solution obtained by reacting 100 μl of trifluoroanhydric acid and 50 μl of trifluoroethanol, which are the optimum conditions obtained in Examples 1 and 2, as a reaction reagent and reacting at a reaction time of 60 minutes and a reaction temperature of 80 ° C. The mixture was injected into a gas chromatography / mass spectrometer or the like, preferably into a gas chromatography / mass spectrometer to obtain a chromatogram of peaks of three kinds of herbicides and an internal standard as shown in FIG. 2. Figure 3 shows the mass spectrum of the three derivatized acidic herbicides, the molecular weight and characteristic fragment ion of each derivatized. The instrument used to determine the concentration of these three acid herbicides is Hewlett-Packard's 5972 mass spectrometer and 5890 plus gas chromatography connected thereto. The ionization method used was electron impact (EI) and the temperature of the ion source was 280 ° C. SIM (Selected Ion Monitoring) mode was used for quantification, m / z 113, the base peak for glyphosate, 123 for m / z and m for endolam, / z was 348. For internal standards m / z 159 was used. The column used for analysis was an ultra 2 column having a length of 25 m, an inner diameter of 0.25 mm, a film thickness of 0.25 μm, helium as the mobile phase gas, and a flow rate of 0.7 ml / min. It was. The temperature of the column was initially raised to 200 ° C. at a rate of 10 ° C./min without the time of staying at 100 ° C., and again to 300 ° C. at a rate of 20 ° C./min. The temperature of the sample inlet was 250 ° C and the temperature of the gas chromatograph and the mass spectrometer connection device was 280 ° C.

Example 4

Take 10 ml of sample from some water purification plant, add 10µl of 2,4-dichlorophenylacetic acid as an internal standard, and completely dry it using vacuum rotary evaporator. Trifluoro anhydride is added to the remaining residue. 50 to 150 µl, preferably 100 µl and 25 to 100 µl of trifluoroethanol, preferably 50 µl, are added and heated at 60 to 90 ° C., preferably at 80 ° C., for 30 to 120 minutes, preferably 60 minutes. After completion of the reaction, the reaction was cooled, dried under nitrogen again, dissolved in 100 μl of ethyl acetate, and then 2 μl was directly injected into gas chromatography for analysis. The calibration curve for quantifying the three herbicides using the mass spectrometer through this analytical method is as shown in Figure 4 and showed a good linearity in the concentration range of 0.2 to 5.0 ㎍ / ℓ.

As described above, the present invention makes it possible to effectively analyze three herbicides, which are difficult to co-extract, in water samples, and has selective and excellent sensitivity to gas chromatography or gas chromatography / mass spectrometer. In addition, it provides optimum analysis conditions for analysis with gas chromatography / mass spectrometer which are generally used for analysis of materials. Therefore, when using the present invention, it is possible to satisfy excellent sensitivity, reproducibility improvement, accuracy, shortening of analysis time, low cost and simplicity, and thus quantitatively analyzing three herbicides, which are harmful to the human body, in a water sample at the same time. It can be widely applied to the analysis of environmental samples, especially water samples.

Claims (4)

As a method of analyzing the concentrations of glyphosate, endortal and chlorambene, herbicides in water samples, the three herbicides were concentrated, derivatized with trifluoroacetic anhydride and trifluoroethanol, and analyzed. An analytical method characterized by preparing a calibration curve for determining, derivatizing three herbicides in various environmental samples and determining the concentration of the three herbicides. The analysis method according to claim 1, wherein the sample is analyzed by simultaneous vacuum evaporation and concentration without using an organic solvent during concentration. The method according to claim 1, wherein the derivatization of the three herbicides consists of 50 to 150 μl of trifluoro anhydride and 25 to 100 μl of trifluoroethanol, a temperature of 60 to 90 ° C. and a time of 30 to 120 minutes. Characteristic analysis method. The analysis method according to any one of claims 1 to 3, wherein the analysis of the concentration in the water quality samples of the three herbicides is performed using a gas chromatography / mass spectrometer.