We Get the Problem in the University laboratory that we detect Diazepam Late. Our goal is to try to detect it in less than 10 min
We wrote to the company and it suggested the method below (The left Graph) But as you can see nothing can be seen.
So We tried to reduce the flow rate from 1,5 ml/min to 0,5ml/min. Therefore we get Diazepam'a Pick but still late ( The right Graph)
Our goal is to detect Diazepam in less than 10min if anyone can suggest to us how to do it
Try this method Article Improved HPLC method for rapid quantitation of diazepam and ...
To me it looks as a well designed and optimized fast HPLC method (ca 5 min) for diazepam in blood
Mr. Karrar,
Looking at your chromatogram, showing a broad and; perhaps, strongly overlapped chromatographic peak; and accounting for the fact that the chemometric treatment of such peaks yields very frequently to significant error contribution to the quantitative anayses, with such clinical tests, like yours, there is great probability to meet the Procurates' staffs, if you carry out such analyses within the European Union.
There is only one currently available and exact method for determination of analytes and it is a mass spectrometric approach. Consider detail in the following discussions [A,B]; together with the references shown, therein. In particula, please, focus your attention on references [2,3] in [A].
The method is our authored. The speed of the data-processing of the mass spectrometric outcome ''intensity'' according to this our approach, depends of your skills to operate with calculator, calculating the introduced by us DSD-parameters, according to our innovative formulas shown, therein (Consider the calculation tasks in reference [3] in [A], which are shown as figure;) and with Excel's tabelle, in preparing the linear relationship between DSD-data of the characteristic MS peaks of your analyte versus the concentration of the analyte. The linear fit is at about ''a second.''
The method is exact; the chemometrics between our theory and experiment of analytes in mixture at pg.(mL)-1 and ng.(L)-1 range of concentrations shows coefficients of correlations up to /r/ = 1.
If you use, for instance, five characteristic MS fragment peaks of CID spectrum of diazepam or any other analyte, the calculation tasks (only) are at about 5 mins for skilled technical staff. The MS measurements are faster than 5 mins, so that....
[A] [https://www.researchgate.net/post/How_can_we_detect_VOCs_in_exhaled_breath_sample_using_ISQ_7000_single_quadrupole_GC-MS_system]
[B]
[https://www.researchgate.net/post/How_to_analyze_two_different_time_point_metabolomics_data]
What size and type of column are you using? How are you dissolving the sample? What volume are you injecting? What gradient methods are being used for the left and right chromatograms?
Without more information, it isn't easy to say why the elution didn't work at the higher flow rate.
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