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Pesticide Residue Analysis - Science topic
Explore the latest questions and answers in Pesticide Residue Analysis, and find Pesticide Residue Analysis experts.
Questions related to Pesticide Residue Analysis
How can I calculate concentation (mg/kg) of sample by using area of peak during analyzing the pesticide residues by HPLC?
I would like to test a biological method of screening vegetables/fruits for the presence of pesticide residue. Since a biological agent is used, the extraction solvent should be non-toxic.
many researchers have analyzed pesticide residue in soil by using GC/MS or GC-ECD. But my lab has GC-FID. can I get the result by using GC-FID?
I would like to ask which Blank type you use for measuring the LOD, LOQ peaks in relation to the blank peak?
are you using matrix-matched blank - if the sample contains analyte+ acetonitrile + Aerosol. Should we use the blank as (acetonitrile and Aerosol )
or you are using the Mobile phase as a blank?
Hi,
I'm setting up a pesticide residue screening method on a Waters UPLC-MS/MS system. Most application notes suggest a 10 mM Ammonium Acetate buffer, but I'm seeing better results (so far) with a 5 mM Ammonium Acetate buffer. Can any one with more experience on pesticide residue screening comment on why a 10 mM buffer might give better performance?
Usually several methods are used to calculate uncertainty. At the time of analytical method development and validation for pesticide residue determination, it is necessary to estimate uncertainty. Could you please tell me which method is comparatively easy to estimate uncertainty in the case of pesticide residue analysis using GC-MS and/or LC-MS/MS. Thanks in advance for your kind cooperation.
Kindly suggest precise and suitable method of extraction of pesticides and their residue analysis via. GC_MS.
I run full scan for Dimethomorph (a fungicide) in GC-MS/MS, and it gives two peaks with different retention times 11.1 and 11.3. I increased temperature from 280 to 320°C and peaks little bit come closer but this is final temperature limit of column and i can't go beyond. Can anybody explain what is possible reason and how i can overcome it. For assistance spectrum is attached below. Thanks

Hello,
I have a question how to make the 4ppm standard mixture, and I should prepare it by mixing 205 pesticide standards in a bottle.
I have looked up a method to produce the 4ppm standard, and I should find out what 25,000 means.
Let me show the process of producing the 4ppm pesticide standard.
First,
201 of 1000ug/ml * 100ul pipetting = 20,100
1 of 100ug/ml * 1000ul pipetting = 1,000
3 of 2000ug/ml * 150ul pipetting = 150
Thus, the sum is 21,250
Second, 25,000 is suddenly calculated as follows.
25,000 - 21,250 = 3,750
3mL and 750uL of Acetone was used to prepare 4ppm standard mixture.
I still have no idea the second process.
Why 25,000 was computed?
I need you help. ;-(
Nowadays, I have conducted a seminar from our students about effects of pesticides to human health, so I would need some article about this subject.
Hello Dear comrades/Peers,
I worked earlier with PGPR and focuses on soil microbiology. But, now working in a lab major in pesticide and its residue analysis. So, I want to start a project merger of Pesticide residue and PGPR followed by bio-remediation.
So, can you help me in this regard; how can I start this kind of project with previous record of such activities. I am working as PhD student at KNU, Korea.
Thanks in advance.
In residue analysis sample preperation is time and solvent consuming. so its may be better to use preperative HPLC for sample preperation.
Dear All
LC MS TOF can carry out non target analysis, in addition the isotopic profile for the obtained data make the identification of these compounds more easier and reduce false positive results. It gives also lower LOQ higher resolution. However, for routine analysis is it require more maintainance, or there are some limitation for using such technique.
For whom is working with lc ms tof, if you have additional benefits or some alarms from using lc ms tof for pesticide residue analysis, please tell me, if their are articles supporting your opinion please send it to me too.
Thank you
Dear All
For a MRM method involve more than 300 pesticide, can one carry out a spiking /fortified sample daily by a representative number of pesticide(10 to 30) rather than spiking by 300 pesticides in order to minimize the consumbtion of the prepared mixture (300 pest) and used it only for preparing calibration. While, preparing a mixture of lower n. pesticide(representitive based on solupility, pKa, stability,..) to be used for spiks preparation.
for the validation, spiking will be carried out using all the pesticides.
To my knowledge, ozone treatment is the Best way to remove pesticide residues. After carefully searching the database, the related paper only describe the treatment time points, ozone concentration , vegetabels and fruit types. If anyone know the mechanism or published papers' link w hould you please tell me. Thanks in advanced!
I would like to know the opinion of experts in the matter, about this issue of special concern for me.
we are working on a.m mentioned compound,
would like to know the acceptable limit of Imidacloprid in South Korea.
The Limits in European Union id 1 mg/kg for cotton kernel extract.
dr vipul doshi
venus lab
A part from GC-MS analysis, is there any simpler method for pesticide residues quantification in fruit and vegetable samples?
I try to quantify paraquat/diquat in potato using LC/MS similar to the attached method but using different LC column. I use standard in solvent with internal standard (IS) to correct for matrix effect (paraquat has enhancement). The issue is the response of the analytes and IS is not consistent in sample matrix so the number is way off (sometimes is too low, sometimes is too high). I injected the same blank matrix with analytes 5 times and response was not the same. The run is isocratic so the matrix of the first injection may show up in the second or even the third injection. The paper use matrix-matched standard with IS (which is over kill) and it may be necessary to do it. I e-mailed the authors but so far no response. any comments are welcome.
I am interested, where Glyphosate and its metabolites can already be found in the environment as wildlife plants and animals and agricultural plants and animals, soil biomes and rivers. Do you know good survey studies with dedected concentrations and dedected limits of Glyphosate and AMPA in plant parts like roots, stem, bark, leaves or fruits and in animal organs and urine? Here in Austria glyphosate residues in European hare (Lepus europaeus) are just of special interest in stomach and urine. Many thanks for your answers! J HUMER
I want your help to find a laboratory for pesticide residue analysis by chromatography ?
I am currently trying to narrow down which set of salts (AOAC, EN, Original) should be used to extract imidacloprid residues from dairy cattle manure using QuEChERS method, as well the sorbents to be used for cleanup using d-SPE. Our initial extractions using just acetonitrile and water (80/20) yielded a dark, yellowish-brown liquid. Samples are to be run on HPLC after extraction. Any comments would be appreciated!
There are other methods for pesticides residues analysis in soil (exception chromatography) !
Actually i'm looking for the sampling rates (cal) of POCIS technology, in order to calibrate them for very high temperature and low velocity (a lake in Burkina Faso).
I'm looking for 50 types of pesticides, from different family type
- Organochlorates
- Organophosphates (Chlorpyrifos-methyl / Diazinon / Omethoate / Profenofos / Triazophos)
- Avermectin (Emamectine Benzoate)
- Carbamate (Carbofuran)
- Neonicotinoid (Acetamiprid/Imidachloprid)
- Pyrethroid (Cyalothrin Lambda / Cypermethrin / Deltamethrin)
- Tetranortriterpenoid (Azadirectin)
I am working on detection of pesticides (especially Organochlorines) in river water. So I am interested to know that in between QuEChERS and SPE which extraction technique provides better detection. Thanx in advance .
I am working in pesticide residues analysis. I need to know about the different methods for conversion of cotton lint into cotton powder to determine the pesticide residues in it.
Thanks in Advance,
Mahmoud.
I want to gain experience in the field of pesticide residue analysis using LC_MS/MS and GC_MS/MS (TRIPLE QUADRAPOLE) SO i want to read a lot of thesis to gain experience from it
thank you in advance
I want to know about the different sample preparations of food in pesticide residues analysis
Is there any specific method for extraction of pesticide residue from human urine sample?
Accepted methodology, solvent for analysis, solvent ratios with time plan, black tea sample extraction procedure for minimum matrices and colour figments effects.
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?
Dear All
I want to use GO-TiO2 for degradation of pesticide. please, may you help me with an effective method for strong binding between GO-TiO2.
Regards,
IS ANY PROVEN TOXIC IMPACT OF ORGANO CHLORO PESTICIDES IN HUMAN being?
Explain more on Garcia et al (1990) method of using glass tubings.
Talk also about the Y-tube olfactometer
Following butanol extraction procedure or pesticide contaminated soils, can I freeze dry the solid and liquid portions of the soil for the determination of residual concentration and bioavailable fractions respectively?
I want to analyze residue of insecticide / fungicide in plant sample and insect. Further I want to do residue analysis in soil also by using HPLC.
I am currently reviewing literature in regards to my undergraduate thesis on Assessment of Cocoa Farmers practices on disposal of Pesticides Waste in Southwestern Nigeria. I need research articles relating to the field and will really appreciate you if you can provide me with some articles.
Thanks.
How to increase the recovery of OPPs from vegetables using GC?
I am doing experiment in rice leaves with different rice pesticides.
I am using Quechers method to extract diazinon from grapes. I followed the original Quechers method. I first contaminated the grapes with pesticides then analyze the residue levels. After blending 200 g grapes, I will take three portions of blended grapes (each portion 10 g) and analyze them using LC/MS/MS. But my results showed that, within the three portions of the same batch, the difference are quiet significant. For example, they can be like 0.1ppm, 0.06ppm and 0.05ppm. Is this normal? I felt the three value should be pretty close since I blended them thoroughly.
I am using a commercial blender for blending. I wonder how can I tell if the grape is blended into homogeneous? I set the blender at high speed and blended for 3min. Is that long enough?
Also, after the blending, should I measured the 10 g portion immediately? Or I should wait for a while to let it equilibrate?
Will any of these affect my final results?
Do I need to add some water to the 10 g portion before addition of acetonitrile and salts?
I have tried to work with the QuEChERS method and used different salts, but the recoveries are very poor. The method must operate for more than ~ 600 different pesticides and I work with GC-MS/MS and HPLC-MS/MS.The methode should be practible for routine analysis.
I work on birds in an agricultural landscape whose primary diet consists of insects and grains. I want to find out the pesticide residue in crops. What part of the plant should I sample and should I collect soil samples?
What should farmers do to avoid pesticides ? thanks everybody.
I have tried to clean up procedure with florisil and silica in QuEChERS process for soil pesticide residues but recoveries are very high during method development.
With sample:solvent ratio of 1:2 (5 g with 10 mL acetonitrile), you have good overall recovery. I used 0.5 g of oil with 30 mL acetonitrile just to maintain amount of oil at 0.5 g for fear of damaging the GC column. The idea of freezing should help out a lot to get rid of the oil. The method is good for lower the LOW to 10 ppb.
While doing pesticide remediation of soil with bacterium, why it is difficult to remediate soil compared to water?
Thanks for the suggestions.
Detailed method for extraction of insecticide residue for HPLC.
multi_residue method for the analysis of hormones in meat liver heart fat using
LC_MS/MS and or GC_MS/MS
I am testing pesticide residues and my last step of extraction is to transfer 0.4ml acetonitrile containing cyprodinil into 1ml of HPLC water. I wonder if cyprodinil is stable in this situatoin if I store my final samples for days before final HPLC analysis?
I'm looking for field or lysimeter tracer studies (particularly using Bromide but other conservative tracers are more than welcome too) which are of long enough duration to capture not just breakthrough and peak concentration but also the final exit of the solute from the profile. Many studies list only the first two results, presumably due to the extensive times required for the tracer to totally exit the profile. I am particularly looking for studies within Ireland or England, and failing that the rest of the EU.
If anyone could suggest some papers that would be much appreciated! Thanks everyone.
In many countries, more and more people like eating organic rice as a new life style of healthy food; however, the yield of this rice is normally low and there are many requirements for field preparation in comparison with those of non-organic rice, which lead farmers to be afraid to invest. If the world turns to produce this kind of rice then we might be faced with the problem of food security since with a low quantity of rice it is not enough to provide for people.
What should be our advice for people or their Government? Producing non-organic rice with a high quantity of rice to provide for the world or the organic rice?
I am using LC/MS/MS to detect pesticide residues (Diazinon, Cyprodinil, and Imidacloprid) on fresh produce. I got the standard pesticides from sigma and tried them on the lc/ms in my lab. But the lc/ms shows no peaks when I inject the 1ppm pesticide solution (in acetonitrile) directly into the lc/ms. But when I dissolve the pesticides in methanol and inject the 1ppm pesticide into the lc/ms, there are obvious peaks. I never saw any similar problems in any articles. Does any one also have the similar issue or know the reason and solutions?
These two chemicals are being used extensively in crop protection along with other group of insecticides. Am researching to find out native soil bacteria to degrade these two pesticides effectively. So hope may some kind of bacterial groups are specifically involved in degradation.
When do you buy a pesticide standard of reference material, has a determinated shelf life. Once it´s finished, how do you managed? do you extend the shelf life, and if you do, how do you managed with it? Do you take a control of them with another standard o how ?
in validation a procedure of pesticide residue analysis,Specificity defined as the ability of the detector (supported by selectivity of extraction and cleanup) to provide signals that effectively identify the analyte. according to SANCO/12571/2013, these signals should be less than 30 % of RL( reporting limit).
my question :1- how can i attain Specificity from standard (analyt in solvent),(analyt in matrix) or ( by spiking the matrix then exctractin, cleanup, injection and determination the detector response)?
2- specificity should be attained for an analyte for each matrix?
When using the instrument (GC or HPLC) for pesticide residue analysis, we found that there are many peaks that are not pesticides we already know , Also the peaks are not from chemicals of pretreatment and matrix. Then how do we know whether composition of these peaks is toxic or not ?
What is the most preferred solvent for dissolving a sample prior to injection on GC/MSD especially for pesticide analysis?
The interference effects of pesticides.
I am analyzing some pesticide residues in soil with HPLC-UV. I have tried different extraction and clean-up methods using acetonitrile or ethyl acetate as sovents and PSA or GCB as dispersive SPE sorbents. However lots of peaks related to impurities appear on the chromatogam when I inject the samples to HPLC-UV. Is there any cheap and effective way I can reduce these impurities in the extracted samples?