Questions related to Organochlorine Pesticides
The examples of organochlorinated pesticides are DDT, heptachlor etc. which have longer residual effects and sevin, furadan etc. are under organocarbamate group that have shorter residual effect. But why?
Singh, A., Nag, S. K., & Singh, S. (2014) tests goat blood for organochlorine pesticides. In their methods it is stated that 10 mL samples were stored in heparinised residue-free 20 ml glass vials at -20ºC until analyzed, but it does not specify how long the samples were stored for.
I am currently doing a study on the analysis of organochlorine pesticides in herbal products. Recently, I had decided to run an aldrin standard into my GC-MS in order to determine the effects of the different concentrations of sulfuric acid on the standard. There were two aldrin standards, one with 10% water and one with merely concentrated sulfuric acid. Even though I had expected only aldrin to appear in the chromatogram, there were other chemical compounds present such as valeric acids and aromatic compounds. May I ask if there is any possible explanation for this result? Could it possibly be due to contamination of the standard solution or maybe an reaction of the standard with the solvent used?
I would like to know the opinion of experts in the matter, about this issue of special concern for me.
I've been read in many literatures that during cytotoxicity assay, when we want to evaluate the effect of a defined compound on the gene regulation in a cell line, or even in some other tests like MTT, serum concentration in complete medium has to be reduced. Could anyone suggest a clear explanation for the reason of this reduction ?
I have read about extraction methods of organochlorine pesticides in sediments and fish tissue using microwave for specific organic compounds, but I don't have this equipment at my institution. Could you direct me to another method with good recovery?
Today I had the opportunity to test some home-made compost made from chicken and rabbit manure, sawdust, feathers and rabbit carcasses, together with plant matter deriving from papyrus plant and other pruned vegetation. Tap water was only applied once at the beginning.
I was quite surprised with the high level of Na and Cl ions present in the tested sample. This led me to ask myself if compost can cause any damage to soil and how can a farmer/gardener get rid of such ions when present in soil. Are there any plants which are capable to extract such ions from soil? and if so, what will happen if vegetative matter deriving from such plants is used to produce compost?
It is to be said that in my country, we experience rainfall only from November until February/March. Tap water is made out of a 50:50 mixture between de-salinized water and ground water. The latter's quality is unknown as the majority is said to be a bit saline as a result to over-extraction throughout the years. Moreover, tap water is treated with chlorine.
Northern Egyptian Lakes and Lagoons ( Mariut, Edku, Brulus, Manzala and Bardaweel). The only one that may have attention is Bardaweel due to its location which is far from pollution and industrial discharge but the rest are suffering a lot from all kind of pollutants and also from cuttage or filling with wastes ad decrease it area so could we as environmentalists and oceanographer provide a good solutions for it?
The literature showed there is a Phytotoxicity of the propanil to Broad leave crop. So, to conquer this problem kindly share your valuable suggestions.
I am using C18 cartridge for extraction and solvent acetonitrile and Dichloromethane(DCM) for elution of organochlorine pesticides. But I am not getting good recovery (only 30%). what other important parameter I need to optimize especially with the pesticides?
I am trying to extract Endrin, Lindane (organochlorine pesticides)from water using organic solvents. Which is the best solvent with higher recovery rates?
which is the best solvent for making calibration standards?
I am going to analysis organochlorine pesticide residues in fish by using GC-ECD with Quechers method. According to quechers method, sample is extracted by acetonitrile solution. We haven’t programmable temperature control unit in injector side. We use 1 uL as inject volume, split less mode. But some literature said quick expansion of acetonitrile (1 ul) is not good for GC column. Can you help me the overcome this?
I want to know whether there is a quantitative method within GC-MS that could synchronously analyze polycyclic aromatic hydrocarbons (16 priority PAHs) and organochlorine pesticides (OCPs) in environmental matrix such as water or sediment? If not, what's the difficult point? Since they could be extracted and purified by using one method at the same time.
I found that no residues in winter and not understand why? please help me even by paper? samples was collected from tap and underground water from egypt?
Out of liquid liquid extraction and Solid phase extraction which one is the best sample preparation method for the detection of organochlorine pesticides (OCPs) in water by HPLC & GCMS?
I am going to analysis of fish samples for organo-chlorine pesticides residues. I have only GC-ECD detector. As well I wish to use the QuEChERS method. Here we havent facility to access AOAC etc. So, any one can help me to find the detail (step by step) method (AOAC or EU or any standard methods) for above analysis?
In EPA cleaning method 50% H2SO4 used, while few other literatures it is 96% or concentrated, which is suitable?
Is there any column chromatographic cleaning required after sulfuric acid/permanganate cleanup for the same compounds?
I want to analyse PAH and organochlorine compounds from Sediment, water and Aerosols. Please suggest the latest available US-EPA methods for the same.
I am extracting PAH, PCBs and other organochlorine compounds using 100%DCM. Then added 100% Hexane in it and concentrated to 1 ml. Then separated the extract in to two for both PAH and organochlorine compounds.
I want to know is the cleaning procedure for organochlorine compounds including PCBs can be done by 96% sulfuric acid or dichromate??
Is there any column chromatography step needed for PCBs and organochlorine compounds from the above procedure?
I'm looking for the TEF or TEQ values of organochlorines including:
- The dioxin-like PCBs (28,52,101,153,138 and 180);
- The organochlorine pesticides (DDT, DDE, DDD, lindane, aldrin, heptachlor and HCB).
Can you help me plz ? !!
I am looking for published data on the neurotoxic levels of organochlorines such as PCBs, HCH and DDTs, in the brain of human/animals.
Could anyone help?
DDT and its metabolites are well known and while there is data available on the effects on frogs and other amphibians, I am struggling to find a paper describing the metabolic pathways followed when amphibians are exposed to DDT or other persistent pesticides.
I am trying to interpret the bio concentration of pesticides but to calculate the Kow I need the octanol concentration of pesticides. Must I carry out the experiment to determine this concentration or can I use derived values from previous studies?