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What is difference between high pressure liquid chromatography and high performance lequid chromatography?
High pressure liquid chromatography (HPLC) and high performance liquid chromatography (HPLC) are often used interchangeably. HPLC refers to modern liquid chromatography systems with high resolution and efficiency, while high pressure liquid chromatography specifically highlights the use of higher pressures in the system to improve separation and speed. Both terms generally refer to the same chromatographic technique.
What type of species can be separated by HPLC but not by gas liquid chromatography?
mixture of enantiomers can be separated by HPLC
What is difference between specificity and selectivity in hplc method validation?
Specificity refers to the ability of an analytical method to accurately measure the analyte of interest in the presence of potential interfering substances. Selectivity, on the other hand, refers to the ability of the method to only detect the analyte of interest while ignoring any other components present in the sample. Both are important parameters in HPLC method validation to ensure accurate and reliable results.
Can melamine detect by HPLC?
Yes, melamine can be detected by HPLC (High Performance Liquid Chromatography). HPLC is a common analytical technique used to separate and quantify compounds in a mixture, including melamine. Detection methods such as UV-Vis spectroscopy or mass spectrometry can be used in conjunction with HPLC to identify and quantify melamine accurately.
Why volatile compounds are analysed in gc but not in hplc?
GC can give very resolved sharp peaks with short run time compared to hplc. additionally, there is less compatibility issue in setting an MS up to a GC than HPLC
What is Difference Between HPLC UV detector Spectrophotometer uv detector?
HPLC UV detector is a component used in high-performance liquid chromatography (HPLC) to monitor eluent absorbance, while a spectrophotometer UV detector is a standalone instrument used to measure the absorption of light at different wavelengths. HPLC UV detectors are specifically tailored for chromatography applications, whereas spectrophotometer UV detectors are more versatile and used for various analytical purposes.
What is the difference between isocratic and gradient?
A separation in which the mobile phase composition remains constant throughout the procedure is termed isocratic(meaning constant composition). The word was coined by Csaba Horvath who was one of the pioneers of HPLC.[citation needed],The mobile phase composition does not have to remain constant. A separation in which the mobile phase composition is changed during the separation process is described as a gradient elution.[3] One example is a gradient starting at 10% methanol and ending at 90% methanol after 20 minutes. The two components of the mobile phase are typically termed "A" and "B"; A is the "weak" solvent which allows the solute to elute only slowly, while B is the "strong" solvent which rapidly elutes the solutes from the column. In reverse-phase chromatography, solvent Ais often water or an aqueous buffer, while B is an organic solvent miscible with water, such as acetonitrile, methanol, THF, or isopropanol.In isocratic elution, peak width increases with retention time linearly according to the equation for N, the number of theoretical plates. This leads to the disadvantage that late-eluting peaks get very flat and broad. Their shape and width may keep them from being recognized as peaks.Gradient elution decreases the retention of the later-eluting components so that they elute faster, giving narrower (and taller) peaks for most components. This also improves the peak shape for tailed peaks, as the increasing concentration of the organic eluent pushes the tailing part of a peak forward. This also increases the peak height (the peak looks "sharper"), which is important in trace analysis. The gradient program may include sudden "step" increases in the percentage of the organic component, or different slopes at different times - all according to the desire for optimum separation in minimum time.In isocratic elution, the selectivity does not change if the column dimensions (length and inner diameter) change - that is, the peaks elute in the same order. In gradient elution, the elution order may change as the dimensions or flow rate change.[citation needed]The driving force in reversed phase chromatography originates in the high order of the water structure. The role of the organic component of the mobile phase is to reduce this high order and thus reduce the retarding strength of the aqueous component.
What are the key differences between reverse phase and normal phase HPLC techniques?
Reverse phase and normal phase HPLC techniques differ primarily in the polarity of the stationary phase and mobile phase. In reverse phase HPLC, the stationary phase is nonpolar and the mobile phase is polar, while in normal phase HPLC, the stationary phase is polar and the mobile phase is nonpolar. This polarity difference affects the retention and separation of compounds in the sample.
What is difference between high pressure liquid chromatography and high performance lequid chromatography?
High pressure liquid chromatography (HPLC) and high performance liquid chromatography (HPLC) are often used interchangeably. HPLC refers to modern liquid chromatography systems with high resolution and efficiency, while high pressure liquid chromatography specifically highlights the use of higher pressures in the system to improve separation and speed. Both terms generally refer to the same chromatographic technique.
What are the key differences between HPLC reverse phase and normal phase chromatography techniques?
In reverse phase HPLC, the stationary phase is nonpolar and the mobile phase is polar, while in normal phase HPLC, the stationary phase is polar and the mobile phase is nonpolar. This difference in polarity affects how compounds interact with the stationary phase, leading to variations in separation and elution times.
What is the difference between low pressure and high pressure gradient HPLC?
In a high pressure gradient pump, each different mobile phase is delivered by an individual pump head and then the mobile phases are mixed at the pump outlet. In a low pressure gradient pump, different mobile phases are mixed using a valve before entering the pump head. As a result of the fact that the low-pressure gradient design uses only one pump head, it is of lower cost. It can also use more types of mobile phase without significant increase of cost. Since solvent mixing point is much closer to the column head in the high-pressure gradient design, it provides a much faster gradient. This is measured using delay volume. The value can be 50-300 uL for high pressure gradient pump and can be 2 to 3 times larger for a low pressure gradient pump. A small delay volume is important when the analysis time is short or the flow rate is low. If the delay volume is too large, it become impossible to obtain reproducible gradient run since the planed composition cannot reach the column head before a run is finished.
How do you use resolution factor in HPLC?
The resolution factor in HPLC is used to quantify the degree of separation between two adjacent peaks on a chromatogram. It is calculated by dividing the difference in retention times of the two peaks by the sum of their peak widths. A higher resolution factor indicates better separation between the peaks.
What are the key differences between HPLC normal phase and reverse phase chromatography techniques?
In normal phase HPLC, the stationary phase is polar and the mobile phase is nonpolar, while in reverse phase HPLC, the stationary phase is nonpolar and the mobile phase is polar. This difference in polarity affects how compounds interact with the stationary phase, leading to different separation mechanisms and selectivity in each technique.
What are the key differences between normal phase HPLC and reverse phase HPLC in terms of their separation mechanisms and applications?
Normal phase HPLC separates compounds based on their polarity, with the stationary phase being polar and the mobile phase being nonpolar. Reverse phase HPLC separates compounds based on their hydrophobicity, with the stationary phase being nonpolar and the mobile phase being polar. Normal phase HPLC is typically used for separating polar compounds, while reverse phase HPLC is used for separating nonpolar compounds.
How do you distinguised np-hplc and rp-hplc?
NP-HPLC is "Normal Phase" HPLC, wherein the solvents used are less polar than the substrate in the HPLC column (e.g. using hexane or dichloromethane with a silica HPLC column). RP-HPLC is "Reverse-Phase" HPLC, wherein the solvents used are more polar than the substrate in the HPLC column (e.g. using Water and Methanol with a octadecylsilane (ODS or C18) column).
What is difference bet GLC and HPLC?
GLC has a stationary liquid phase and gas moving phase HPLC had a stationary solid phase and liquid moving phase HPLC is done under high pressure. HPLC can be used for thermally unstable compounds as opposed to GLC HPLC can be used for polar or low volatile compounds as opposed to GLC
Retention time calculation for hplc?
why RT was shifting & how to RT calculation in HPLC
