I doubt that you will extract either of these compounds under neutral conditions. Fluroxypyr you will almost certainly have to extract under acidic conditions; not sure about the best conditions for prothioconazole. You might want to look at the EU methods for acidic herbicides.

Mark Krause Thank you for your answer. In your opinion, would it be possible to adapt Dutch Mini Luke for acidic condition extraction, if yes, which solvent would you suggest I should acidify?

Dear Mathavan

Please let me know the detector wavelength.

and please explain how you did the filtering step.

regards.

The two herbicides to be extracted do not have the same physicochemical properties, especially from the point of view of acidity. Look at the chemical structures for this! If you can detect each herbicide, only according to their standards! When these two herbicides in the soil, there are interactions that modify their behavior and therefore their extraction

Dear Davoud Beiknejad the wavelength that I used was 254 nm, while the filtering processing involving me filtering reconstituted extract of 500 uL volume through 0.2 um hydrophilic syringe filters.

Safia Taleb thank you for your answer.

hi my dear

The choice of procedures and precautions depends on the severity of the contamination (whether it poses risks and the extent of these risks, and the more severe the expected risks, the long-term and decisive measures and solutions need to be). It also depends on the degree of vulnerability and sensitivity of neighboring areas to pollution. For example, an industrial zone may be more acceptable than others to experience slightly higher pollution rates than its counterparts in residential or agricultural areas. This matter also depends on the availability of the necessary financial funds for investment and operational costs. In addition, it is important to estimate what If the required measures are necessary to ensure the immediate protection of the population, or to prevent the spread of pollution and cause harm in the future. " The following guidelines are applied when choosing what actions to take:

If the topsoil is contaminated and poses a "danger to human health," then its removal is recommended.

If the topsoil is polluted, but it does not pose a threat to human health, measures may not be necessary. However, perhaps for psychological reasons (ie, calming the feelings and reassurance of the area's residents) it is recommended that appropriate preventive measures be taken.

Costly measures (such as removal and containment) are only necessary when the degree of risk is high, and preventive measures are neither guaranteed nor conclusive.

If the pollution has reached the subsurface layer of the soil, then removing the soil surface is not necessary, as this layer forms a cover that prevents human contact with the pollution site and prevents further contamination towards the groundwater, then containment procedures here are correct (through complete sealing off the surface layer of the soil so that it prevents rainwater infiltration from penetrating into the soil and transferring pollution from under the soil to the groundwater).

If groundwater becomes contaminated and becomes a danger to people's health, this contaminated water must be removed. If the obsolete and polluting pesticides have been removed, then it is also imperative that “the process of removing pesticides from the water continues as long as there is contaminated water. Here too” prevention precautions must be applied, especially in poor countries, so that the procedures are followed seriously and effectively.

But if the groundwater has been polluted but does not pose a risk, and the pesticides stored under improper conditions have been refilled or removed from the site, then no procedures are required. However, it is necessary to monitor the area (by taking samples once a year from existing wells) to ensure that pollution does not return.

Please look at the following below links which may help you in your analysis:

https://pubmed.ncbi.nlm.nih.gov/15620085/

https://apvma.gov.au/sites/default/files/publication/13941-prs-prothioconazole.pdf

Thanks

fluroxypyr in soil: It depends on the nature of the soil. In one of the soils from palm oil plantation, four methods have been tried. You may decide the method depending upon the nature of soil you intend dealing with:

The first of the four methods of analysis for fluroxypyr in soils (palm oil plantation) involves extraction with 0.05 M NaOH in methanol followed by acid base partition for purification. Derivatization of the concentrated material and cleaning with florisil column and finally analysed by gas chromatography equipped with electron capature detector. This method enables 70-104% recovery with minimum detection limit at 5 microg/kg.

The second – solid extraction using a horizontal shaker followed by high performance liquid chromatography (HPLC) equipped with UV detector. Recovery rate ranges from 80-12% IF the soil is spiked with fluroxypyr at 0.1-0.2 microg/g in soil.

The third method involves solid liquid extraction using ultrasonic bath. Recovery of fluroxypyr at spiking levels of 4-50 microg/L ranges from 88-98% +_3.0-5.8% with minimum detection limit of 4 microg/kg.

In the fourth method, fluroxypryr was extracted using solid liquid extraction followed by cleaning up with OASIS HLB-polyviny dibenzene with a recovery of 91 – 95% (relative standard deviation of 4.2-6.2%)