Method for simultaneously determining multiple heterocyclic pesticides, degradation products and intermediates in water by adopting liquid-liquid extraction/liquid chromatography

Abstract

The invention provides a method for simultaneously determining various heterocyclic pesticides, degradation products and intermediates in water by liquid-liquid extraction / liquid chromatography. The method comprises the following steps of by using dichloromethane as an extractant, extracting a neutral water sample added with sodium chloride, extracting the target, drying, and concentrating the extract to obtain the target product; purifying the extract, and replacing the solvent with acetonitrile or directly replacing the solvent with acetonitrile; and separating and detecting by using a liquid chromatograph, carrying out gradient elution by using a ternary mobile phase or a binary mobile phase during separation, and quantifying by using an external standard method according to the qualitative retention time to obtain the concentration of each target object in the water sample. The method is efficient, easy to operate, low in detection limit, good in accuracy and precision and good inlinear relation, 16 heterocyclic pesticides, degradation products and intermediates can be detected at the same time, and problems that an existing heterocyclic pesticide detection method is not highin integration level, incomplete in target object coverage and even vacant, tedious in step and high in detection cost are solved; requirements of heterocyclic pesticide environment monitoring and management in China at the present stage are met.

Description

Technical field:

[0001] The invention relates to the technical field of environmental monitoring, in particular to a method for simultaneously measuring various heterocyclic pesticides, degradation products and intermediates in water quality by using liquid-liquid extraction / liquid chromatography. Background technique:

[0002] Cyclic compounds in which certain positions of the ring-forming carbon chain are replaced by non-carbon elements such as O, S, and N are called heterocyclic compounds. Heterocyclic pesticides refer to various heterocyclic compounds with insecticidal, herbicidal and bactericidal effects. Heterocyclic pesticides are the most rapidly developed pesticides in recent years. They are highly efficient and relatively low-toxic, and are often used in the control of crop diseases and insect pests. In recent years, the representative varieties of heterocyclic pesticides with large production tonnage, serious pollution to humans and the ecological environment, and...

Examples

Embodiment 1

[0067] Determination method of heterocyclic pesticides in domestic sewage:

[0068] The domestic sewage was collected in a 4L brown glass bottle with a ground stopper, the pH of the water sample was adjusted to 6-8 with hydrochloric acid solution or sodium hydroxide solution, and immediately stored at 4°C, the extraction was completed within 7 days, and the analysis was carried out within 40 days.

[0069] (1) Liquid-liquid extraction: Accurately measure 250ml of domestic sewage water sample and place it in a 500ml separatory funnel, add 75g of sodium chloride and shake well, extract with 90ml of dichloromethane three times, 30ml each time, shake the extraction for 5min (note that the gas), after standing for stratification, the organic phase was dehydrated by anhydrous sodium sulfate, combined three dichloromethane extracts, the extract was concentrated to about 1ml with a nitrogen blowing concentrator, 10ml of acetonitrile was added, and the concentration was continued to abo...

Embodiment 2

[0088] Determination method of heterocyclic pesticides in pesticide industrial wastewater:

[0089] The wastewater from the pesticide industry was collected in a 4L brown glass bottle with a ground stopper. The pH of the water sample was adjusted to 6-8 with hydrochloric acid solution or sodium hydroxide solution, and immediately stored at 4°C. The extraction was completed within 7 days and analyzed within 40 days.

[0090] (1) Liquid-liquid extraction: Accurately measure 250ml of domestic sewage water sample and place it in a 500ml separatory funnel, add 75g of sodium chloride and shake well, extract with 90ml of dichloromethane three times, 30ml each time, shake the extraction for 5min (note that the gas), after standing for stratification, the organic phase was dehydrated by anhydrous sodium sulfate, combined three dichloromethane extracts, and the extract was concentrated to about 1ml with a nitrogen blowing concentrator, to be purified;

[0091] (2) Purification: Activate...

Technical field:

[0001] The invention relates to the technical field of environmental monitoring, in particular to a method for simultaneously measuring various heterocyclic pesticides, degradation products and intermediates in water quality by using liquid-liquid extraction / liquid chromatography. Background technique:

[0002] Cyclic compounds in which certain positions of the ring-forming carbon chain are replaced by non-carbon elements such as O, S, and N are called heterocyclic compounds. Heterocyclic pesticides refer to various heterocyclic compounds with insecticidal, herbicidal and bactericidal effects. Heterocyclic pesticides are the most rapidly developed pesticides in recent years. They are highly efficient and relatively low-toxic, and are often used in the control of crop diseases and insect pests. In recent years, the representative varieties of heterocyclic pesticides with large production tonnage, serious pollution to humans and the ecological environment, and...

Examples

Embodiment 1

[0067] Determination method of heterocyclic pesticides in domestic sewage:

[0068] The domestic sewage was collected in a 4L brown glass bottle with a ground stopper, the pH of the water sample was adjusted to 6-8 with hydrochloric acid solution or sodium hydroxide solution, and immediately stored at 4°C, the extraction was completed within 7 days, and the analysis was carried out within 40 days.

[0069] (1) Liquid-liquid extraction: Accurately measure 250ml of domestic sewage water sample and place it in a 500ml separatory funnel, add 75g of sodium chloride and shake well, extract with 90ml of dichloromethane three times, 30ml each time, shake the extraction for 5min (note that the gas), after standing for stratification, the organic phase was dehydrated by anhydrous sodium sulfate, combined three dichloromethane extracts, the extract was concentrated to about 1ml with a nitrogen blowing concentrator, 10ml of acetonitrile was added, and the concentration was continued to abo...

Embodiment 2

[0088] Determination method of heterocyclic pesticides in pesticide industrial wastewater:

[0089] The wastewater from the pesticide industry was collected in a 4L brown glass bottle with a ground stopper. The pH of the water sample was adjusted to 6-8 with hydrochloric acid solution or sodium hydroxide solution, and immediately stored at 4°C. The extraction was completed within 7 days and analyzed within 40 days.

[0090] (1) Liquid-liquid extraction: Accurately measure 250ml of domestic sewage water sample and place it in a 500ml separatory funnel, add 75g of sodium chloride and shake well, extract with 90ml of dichloromethane three times, 30ml each time, shake the extraction for 5min (note that the gas), after standing for stratification, the organic phase was dehydrated by anhydrous sodium sulfate, combined three dichloromethane extracts, and the extract was concentrated to about 1ml with a nitrogen blowing concentrator, to be purified;

[0091] (2) Purification: Activate...

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