Dear Shefin, phtalates mainly derive from plastics (they are additives used in plastic manufacturing). My advise is check all plastic materials which your extract was in contact with (beckers, vials, bottles, tubes, pipettes). Did you use chlorinated solvents for extraction? They are the most efficient solvents in extracting phtalates from plastic. In extraction processes it's better to always use glassware.

Regards

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

https://iopscience.iop.org/article/10.1088/1742-6596/1294/6/062013/pdf

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5334330/pdf/13568_2017_Article_351.pdf

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5361076/pdf/main.pdf

Thanks

They not from the plant extracts but from the solvent used in extraction, sample preparation. The point to be noted is their concentration(s). A prior check on the solvent quality, better running the GC/GC-MS may be helpful. Usually, phthalates are not plant origins, otherwise a strong analytical proof is required. HPLC/LC-MS being less sensitive than the GC may also be helpful to rule out the presence! Thank you

Hello Shefin,

phthalates are always of artificial origin. I am not aware of any natural source from which phthalates could come. Unfortunately they are ubiquitous and a plague to any analyst. However, they can also be used as fixed points for an exact mass calibration and thus make a virtue out of necessity.

Regards

Markus

They would have been natural if they were plant extracts, which they aren't.

it could be as phthalate present in many parts of plant coming from soil nutrient but it is uncommon . i recommend to google it

Thank you Isam Eldin Hussein Elgailani Riaz A. Khan Markus Christ Muhammad Idrees Nedhal Ahmad Aldouri for your valuable answers. Your answers helped me to clarify and confirm my doubts. Well appreciated ..With Best Regards

Dear Shefin, phtalates mainly derive from plastics (they are additives used in plastic manufacturing). My advise is check all plastic materials which your extract was in contact with (beckers, vials, bottles, tubes, pipettes). Did you use chlorinated solvents for extraction? They are the most efficient solvents in extracting phtalates from plastic. In extraction processes it's better to always use glassware.

Regards

I would like to add to the previous answer that phthalates can also appear due to septum bleed. Usually this happens with new non-conditioned septa and at high injector temperatures.

Dear Claudia Fattuoni Thank you for the detailed technical explanation.

They aren't natural, so they cant be plants extracts

I totally agree with Claudia Fattuoni. Phthalates are additives coming from plastic materials. They are added as plasticizers to give a certain amount of flexibility to the plastic products. If you are using plastic apparatus for sample preparation, there is a very high possibility of these plasticizers getting co-extracted because of the solvents that are used for extraction. For very sensitive analysis, it is always advisable to use clean glass apparatus for sample preparation and storage. Phthalates can be easily identified in GCMS analysis by EI mode by the base peak at m/z 149. An exception is Dimethyl Phthalate which has a base peak at m/z 163.

Running a full sample processing blank will answer the question. Using the same quantity of solvent, used in each step, evaporating down to the same volume, and using the same amount of the extract of no sample will tell you whether your process is the source of the phthalates. Also, beware of handling the samples with vinyl gloves or any vinyl in use in the system, including tubing for handling water.

If you identify the source as being part of your processing of the sample, and it doesn't interfere with the analyses, the phthalates may actually become a useful internal standard for verifying the retention times in the GC as well as the fragmentation patterns from the MS. Most of the phthalates have significant quantities of information concerning retention indices in GC and variations in fragmentation patterns.

Well, you've got an answer already, yet i have something to add.

We had the same problem with intense phtalates peaks on my chromatogram in the past. They didn't affect my analysis, but they definitely were annoing. Step by step we excluded all possible sources of them and the main contribution was on the last stage - the vial. Well, not the vial itself but the vial cap. It was made of plastic/ptfe. So we simply changed the cap to aluminium/ptfe. This action decreased the signals of phtalates on chromatogram pretty much. So now we use for GCMS analysis only aluminium/ptfe caps. Hope this will help you.

Yes - phtalates are as annoying as BHT and other artificial oxidants, emulsifiers, consistency aids and so on. We are living in an artificial world and it became an art to distinguish the real natural products. Watch out!!! A researcher in Sweden for 5 years or more has been documenting alkanes in his reports until we discovered it was resulting from the grease on the gas supply valves and fittings..

@ Will these phthalate problems arise in eppendorfs too?

Yes, unless the Eppendorfs are made of inert glassware, but they area not. If you wear plastic gloves and "extract" your hands (not voluntarily) then you will have the phtalates in your concentrate (after evaporizing the solvent). If your solvent is shipped in plastic bottles then you will have A LOT of phtalates. Don't forget you are concentrating everything, not just your compounds of interest!!! The instruments, especially mass spectrometers are very sensitive, down to nanogram per liter you will detect (and have to, because your analytes are traces many times). At our lab in Sweden, we had the work of an entire week to clean everything before starting to extract. Don't even think about to keep your samples in plastic containers!!! The best method is to prepare a blank and subtracting that blank from your sample result (easily done nowadays with the MS software). Blank: you repeat exactly all steps normally done without your sample of course. Many times it is just to concentrate your solvent and inject 1 microliter of that.

Dear Shefin, Eppendorf tubes are high quality products but, to avoid problems, I use them only when no-chlorinated solvents are involved. You can use them to store biological samples (they are water solutions), or to perform experimental steps with short contact time. The best choice is always to use glass vials.