Table of Contents
What is baseline width in chromatography?
A chromatographic peak’s baseline width, w, as shown in Figure 12.2. 4, is determined by extending tangent lines from the inflection points on either side of the peak through the baseline.
What is peak width in HPLC?
Peak width is the distance between points where lines tangent to the peak’s left and right inflection points intersect the baseline, and is calculated using equation (1).
What is the theory of HPLC?
HPLC Theory HPLC works following the basic principle of thin layer chromatography or column chromatography, where it has a stationary phase ( solid like silica gel) and a mobile phase (liquid or gas). The mobile phase flows through the stationary phase and carries the components of the mixture with it.
Why is baseline resolution important?
For example, each compound’s contribution to the overall structural information provided by the mass spectrometer will not be distinguishable, thus their identification will be hampered. This is the reason why it is important to achieve baseline resolution (R = 1.5) as the ultimate goal for all peaks.
What is the tailing factor in HPLC?
Symmetry factor (S, also called “tailing factor”) is a coefficient that shows the degree of peak symmetry.
Why is HPLC peak broad?
Sometimes broad HPLC peaks are due to the injection of the sample into not suitable solvent. For example, if you inject your target analyte solved in hexane onto a C18 column and further you use a water:acetonitrile gradient, your peaks will be too broad and will tail.
What is K factor HPLC?
The retention (or capacity) factor (k) is a means of measuring the retention of an analyte on the chromatographic column. Determination of Retention Factor (k) A high k value indicates that the sample is highly retained and has spent a significant amount of time interacting with the stationary phase.
What is baseline resolution HPLC?
Re: baseline resolution Resolution is the ratio of center-to-center separation (the difference in retention times) to the average baseline width. Start by assuming two perfectly Gaussian peaks of the same width and same height.
What is NTP in HPLC?
NTP and HTP Theory NTP is constant for a column for all components, regardless of the component used to calculate it; HTP is also therefore a constant. NTP can be used to calculate resolution of two peaks if only the retention times are known.
How do you decrease peak width?
In both cases the solution is quite simple: Dilute the sample or reduce the injection volume. The pH of the mobile phase can also have a strong influence on the peak width. Depending on the chemical property of a sample, it can be ionized in different ways, i.e., completely protonated, deprotonated or neutral.
What is void volume in HPLC?
The HPLC column void volume denoted Vm or V0 is in simple terms the volume of the mobile phase in the column. It is the part of a fraction that when added to the volume of the stationary phase makes up a whole fraction or 100% volume.
What is separation factor?
The selectivity or separation factor, α, is a ratio of mass distribution coefficients given in equation 19.12, and so is a thermodynamic rather than a kinetic factor. The value of α depends mainly on the nature of the two solutes, on the stationary phase and, in liquid chromatography, the mobile phase.
What is K capacity factor?
What is K Prime in HPLC?
ANSWER. K’ (K prime, or capacity factor) in chromatography is used to help assess if a peak is going to give reproducible and linear results over time. This ensures that small errors in mobile phase or pH do not have a large impact on retention time or response of the peak.
How do you find the peak width of a baseline?
An estimation of peak width can be made: w = 1.7 × w1/2. height or at ½ peak height. Retention and peak width are used to calculate various performance measurements; in this way, the separating power of a system can be calculated and compared.
How do you find the baseline resolution?
That is, the resolution is the difference in retention times divided by the average baseline peak width (thus the factor of 2 in equation 1). The peak width at the baseline for a Gaussian peak is 4σ (4 standard deviations), whereas at the half-height, it is 2.354σ, so the factor in equation 2 is (2 × 2.354/4) = 1.18.
What is the basic theory of HPLC?
14 1 Basic HPLC Theory and Definitions: Retention, Thermodynamics, Selectivity, Zone Spreading, Kinetics several simultaneous trends in liquid chromatography today. Many of the trends are logical consequences of the basic theory we have just covered. For example, we learned from the basic theory that the resolution (R
How do you calculate h in HPLC?
: (1.10) 8 1 Basic HPLC Theory and Definitions: Retention, Thermodynamics, Selectivity, Zone Spreading, Kinetics H can thus be calculated from the base width, retention time, and column length. H will be in length unit and can apparently be attributed to the width of the peak relative to its retention time.
What is the retention factor in HPLC?
x 1 1k : (1.2) 6 1 Basic HPLC Theory and Definitions: Retention, Thermodynamics, Selectivity, Zone Spreading, Kinetics Here, k is the retention factor.
What are the trends in HPLC?
14 1 Basic HPLC Theory and Definitions: Retention, Thermodynamics, Selectivity, Zone Spreading, Kinetics several simultaneous trends in liquid chromatography today. Many of the trends are logical consequences of the basic theory we have just covered.