Chromatography peak area/height

Insufficient assay accuracy and Sample Model A Chromatography Peak area or peak height vs. re-... 

The quantitative determination of a component in gas chromatography using differential-type detectors of the type previously described is based upon meas urement of the recorded peak area or peak height the latter is more suitable in the case of small peaks, or peaks with narrow band width. In order that these quantities may be related to the amount of solute in the sample two conditions must prevail ... 

The area of a peak is the integration of the peak height (concentration) with respect to time (volume flow of mobile phase) and thus is proportional to the total mass of solute eluted. Measurement of peak area accommodates peak asymmetry and even peak tailing without compromising the simple relationship between peak area and mass. Consequently, peak area measurements give more accurate results under conditions where the chromatography is not perfect and the peak profiles not truly Gaussian or Poisson. 

Figure 5.2 Electrospray-MS-MS signal response of seven of the pesticides versus eluent flow rate, based on (a) peak area, and (b) peak height , atrazine , simazine , diuron x, isoproturon , chlorfenvinphos , chlorpyrifos O, alachlor. Reprinted from 7. Chromatogr., A, 937, Asperger, A., Efer, J., Koal, T. and Engewald, W., On the signal response of various pesticides in electrospray and atmospheric pressure chemical ionization depending on the flow rate of eluent applied in liquid chromatography-mass spectrometry , 65-72, Copyright (2001), with permission from Elsevier Science.

Foley, J. R, Systematic Errors in the Measurement of Peak Area and Peak Height for Overlapping Peaks, Journal of Chromatography 384, 1987, 301-313. 

Successful use of modern liquid chromatography in the clinical laboratory requires an appreciation of the method s analytical characteristics. The quantitative reproducibility with respect to peak height or peak area is quite good. With a sample loop injector relative standard deviations better than 1% are to be expected. The variability of syringe injection (3-4% relative standard deviation) requires the use of an internal standard to reach the 1% level (2,27). 

Katori et al [84] used a high performance liquid chromatographic method for the determination of primaquine phosphate tablets. Chromatography on a TSK Gel-4 (octadecylsilanized) column was used to determine the active ingredient in tablets and injections for treating tropical diseases. The mobile phase used is 26% acetonitrile in 0.05-M pH-3 phosphate buffer and the drug was detected at 260 nm. The peak area and peak height reproducibilities were <1.69%, and results compared well with those of other methods. 

Most chemometricians prefer inverse methods, but most traditional analytical chemistry texts introduce the classical approach to calibration. It is important to recognise that there are substantial differences in terminology in the literature, the most common problem being the distinction between V and y variables. In many areas of analytical chemistry, concentration is denoted by V, the response (such as a spectroscopic peak height) by y However, most workers in the area of multivariate calibration have first been introduced to regression methods via spectroscopy or chromatography whereby the experimental data matrix is denoted as 6X , and the concentrations or predicted variables by y In this paper we indicate the experimentally observed responses by V such as spectroscopic absorbances of chromatographic peak areas, but do not use 6y in order to avoid confusion. 

As a chromatographer, there will come a time when it will be necessary to gather data and present the summary of that data in order to demonstrate how good your chromatography is. The two things most people need to summarize for others interested in a chromatographic method are accuracy and precision of retention time, of peak height (or peak area), and of the total analysis. 

The methods of quantitative analysis are essentially tiiose inherited from gas chromatography. Peak hei t or pe area can be measured, either manually or with electronic devices. Peak height measiu-ements have the advantage of simplicity but are sensitive to changes in peak shape peak area measurements should always be used where peaks are broad and tailing. 

For the most part, contemporary computer chromatography software does not provide for situations where (r l) so the analyst can only use peak height data from the program and make the corrections manually. Alternatively, the chromatogram can be processed completely manually in which case peak areas can be used. The magnitude of any error that can arise from not correcting for (r) when it is other than unity can only be accessed, if and when the actual value of (r) is determined in the manner discussed in chapter 2. Unfortunately very few instrument manufacturers provide a value for (r) and thus the... 

Most analytical determinations employing liquid chromatography are based on the measurement of peak area (A) or peak height (fit). The peak area is equal to the zeroeth moment of the Ciaussian distribution... 

Peak area, peak height Properties of peak-shaped signals that can be used for quantitative analysis used in chromatography, electrothermal atomic absorption, and other techniques. Peptization A process in which a coagulated colloid returns to its dispersed state. 

Analytical chromatography aims to achieve an adequate, not necessarily a maximum, resolution of solute bands to identify and to quantify the analytes based on their retention coefficient, peak height and peak area. Information on the analytes is the target. 

---