Do you have any idea why I am getting these kind of chromatograms for my analytes (LC-MS/MS, mycotoxin, grains)?

More Nasim Alijanimamaghani's questions See All

How can I magnify an image without changing the dimension in matlab?

Hi everyone. For the last part of my project I have to see how does my program respond to a magnified image. The magnification has to be a part of the code . I've tried imresize() , it will be...

10 February 2021 8,279 10 View

What is the main difference between "CD105+ Endothelial Cells" and mesenchymal stem cells?

since CD105+ Endothelial Cells are CD31 negative, how do we differentiate them in cell culture from mesenchymal cells? is it using vwf? thanks a lot

03 February 2021 5,362 2 View

How to know initial values for non-linear regression?

Does anyone know a reliable methodology to estimate the initial values of theta1 (or A) and theta2 (or B) in a non-linear model? For example, a = (A+Bx/hc)(hc/x-Eg) How to reliably estimate the...

17 January 2021 1,327 1 View

How can i get AMPS-1D resources?

I am trying to model a photovoltaic device using AMPS-1D software. But once I am submitting it to queue, it remains there for infinite amount of time without giving the result. I couldnt...

11 January 2021 1,829 1 View

How can I omit some special part of an image in matlab?

Hi I'm trying to edit my input image which is a simple Persian letter. I want to omit the dots of the letter. I can do it with Photoshop of course, but it would be more technical if I could do it...

14 December 2020 201 5 View

How can I produce hyper immune mouse against human FZD7?

My thesis about the production of mouse anti-human FZD-7 monoclonal antibody (against the 33-185 AA of FZD7) by the hybridoma method. I have a problem with mouse immunization by FZD7. In ELISA the...

10 October 2020 3,741 2 View

How can I design Vanderlugt filter in Matlab?

Hi everyone I need some help in designing Vanderlugt filter in Matlab. I want to design this filter and later use it in a 4f optical correlator. As I tested my designed filter and I'm not sure...

19 September 2020 8,662 7 View

What is the best way to show my live data as an online dashboard using Python?

Hello, I have plenty of data coming from my sensors every minute and I analyze them in Python. I want to make a realtime online dashboard to make a nice representation of my data. My ultimate...

28 May 2020 1,149 3 View

What is the best practice to implement machine learning on real world sensor data?

Hello, I have a few sensors in a home. I am going to continuously receive data fro these sensors, and do Machine Learning (in Python. Keras) on stored data every 24 hours. One possibility to do...

20 May 2020 9,285 7 View

Is there an open-source IoT platform to do online Machine Learning for free?

I am going to connect my sensors to an IoT platform to receive their data and store. Then I need to do machine learning predictions (as Python script) every 24 hours to do predictions for the next...

20 May 2020 590 5 View

How to compare different concentrations of nanoparticles for characterization from ICP-MS?

I took measurements of different concentrations of 15 nm and 5 nm Au nano particle solutions. I'm trying to determine which concentration I measured gives the best reading overall. I also...

02 March 2021 7,626 1 View

Any research papers for extraction of nutrient deprivation on macroalgae? Analysed by HPLC-UV and GC/MS. Possibly from macroalgae genus Rhizoclonium?

I am doing my thesis on the nutrient deprivation on the macroalgae Rhizoclonium sp. I will be analysing the levels over a period of roughly 5 days by HPLC-UV and GC/MS. I will be using seawater as...

28 February 2021 6,477 1 View

I want to performe MALDI-TOF MS for bacterial identification, I would appreciate it if anyone can tell me the matrix solution preparation protocol ?

based on what I've studied on multiple papers, for peptide and protein identification Alpha-cyano-4-hydroxycinnamic acid (CHCA) is an appropriate matrix to use, I also know that the CHCA powder...

26 February 2021 6,799 3 View

How does the injection volume impact LLOQ and ULOQ in regression analysis (LC-MSMS)?

Hello, I have run into an issue that has sparkled a debate at work: is the LLOQ/ULOQ impacted by injection volume under the following circumstances: 1) Same dilution factor of all samples 2)...

23 February 2021 9,159 3 View

Why ICP-MS test for Teflon filters that collected PM2.5, show really high results in the millions of ug/g ?

I analyzed soil and ash samples using ICP-MS for 28 metals, then I resuspended those samples to collect PM2.5 particles in a filter using a selective inlet inlet. My only issue that Fe and Al...

13 February 2021 7,592 3 View

What influences inter-day reproducibility in UPLC-MS/MS analysis?

I was analyzing some metabolites in human plasma. While the intraday precision of these metabolites was acceptable ( less than 20%), the interday precision was quite large. So what influences...

13 February 2021 9,183 9 View

How do I prepare and store insect samples for JH measurements?

I need to preserve termite samples for future quantification of juvenile hormone in their bodies. Or extract the Juvenile Hormone and keep that samples stored for future quantification. I may need...

09 February 2021 1,995 1 View

MS/MS protein analysis?

Hi Everyone: I want to quantify the relative amount of a protein in 2 samples. I will first digest the sample with trypsin, and subject the resulting peptides to LC-MS/MS analysis. I will then...

25 January 2021 8,333 3 View

2.6 Drying gas flow controller cannot regulate the requested setting after a fixed amount of time?

We keep getting this error on our Agilent 6470 TQ. We were told it could either be our N2 generator or filter traps. We've called the manufacturer of our generator and they believe it's working...

21 January 2021 2,969 1 View

How to distinguish pure and adulterated honey using NMR spectroscopy?

What are the common adulterants in commercial honey? how to identify pure honey and adulterated honey with the help of NMR spectroscopy? Is there any other technique to check purity of honey?

20 January 2021 5,456 12 View

Nasim Alijanimamaghani

Dear Noel W Davies

You are absolutely correct.

I just fixed this yesterday!

Our mycotoxins are commonly solved in ACN, and my student forgot to evaporate and reconstitute them in injection solution. She injected them in ACN to LC-MS/MS directly! and this was the reason that I got these peaks. I know this is a simple step but we all know that they are just students!

Regards,

Nasim

William Letter

Read this training article (the answer to your question can be found under point #2; "What should I dilute my sample in?").

"HPLC Injection Volume: What Should I Dilute It In and How Much Sample Can I Inject?"; https://hplctips.blogspot.com/2023/07/hplc-injection-volume-what-should-i.html

Thank you William Letter

I appreciate it.

Meisam Feizi

As Professor Noel W Davies said before that you have to check the credibility of your method and then check your previous publication on this sample

Carlos Joel Salas-Montantes

Maybe it is a problems in some grains, you need to ultracentrifugate the samples before the evaporation and after the reconstitution. So, you can use this little columns for clean the samples (https://www.romerlabs.com/es/catalog/product/view/id/2523/s/mycospin-400-multimycotoxin/category/97/) it is special for mycotoxins.