1. What is GLP?
GLP means Good Laboratory Practice. It is a framework or pattern under which research work is planned, performed, monitored, recorded, reported, and archived.
2. Why is GLP followed in the lab?
Following GLP standard minimizes the chance of errors due to human factors.
- It supports product registration and assures the suitability of data to regulatory authorities.
- It helps reduce industry and government costs by avoiding duplicative testing.
- It aids in re-creating a study from the recorded data and information.
3. What is Calibration Curve?
Calibration curve is the relationship between the various concentration of analyte in a suitable solvent or matrix and the signal response of the instrument.
4. Do you know about MSDS?
Material Safety Data Sheets are used to handle chemical use in a laboratory. They are issued with every chemical that any lab uses or stocks.
5. Do you know what is blank?
Blank term is used to refer the sample tube which does not contain the analyte.
6. What is Titration?
Titration is a process of determining molarity of a base or an acid.
7. What is Karl Fischer Titration?
Karl Fischer titration is a classic titration method in chemical analysis that uses coulometric or volumetric titration to determine trace amounts of water in a sample.
8. Explain the term Aliquot and Diluent?
- Aliquot: It is a measured sub-volume of the original sample.
- Diluent: Material with which sample is diluted.
9. What is the difference between Molarity and Normality?
Both techniques are used to determine the amount of chemical present in the solution. However, they are almost similar but differ in:
Molarity
- Molarity is used to know the total amount of molecules in a 1-liter solution.
- It is expressed as moles of a compound per liter of solution.
Normality
- Normality is used to know the total number of reactive units in 1 liter of solution.
- It is expressed in equivalents per liter.
10. What is mole?
Mole is the unit used to define the number of chemical substance present in the substance.
11. What is valency?
Valency is a property of groups or atoms, equal to the number of atoms of hydrogen that the group or atom could combine with or displace it in forming compounds.
12. What is buffer?
A buffer is an aqueous solution which has highly stable pH. It is a blend of a weak acid and its conjugate base or vice versa.
On adding a small amount of base or acid to buffer, its pH hardly changes.
13. What is oxidation and reduction reaction?
- Oxidation = When there is a loss of hydrogen or electrons OR gain of oxygen is known as Oxidation reaction.
- Reduction = When there is a gain of hydrogen or electron OR loss of oxygen is known as a reduction reaction.
14. What is Chromatography?
Chromatography is an analytical technique commonly used for separating a mixture of chemical substances into its individual components, so that the individual components can be thoroughly analyzed.
15. What is co-chromatography?
Co-chromatography is the procedure used to detect an unknown substance by comparing the chromatic comparison with a known substance.
16. What is Column in Chromatography?
A Chromatography column is a device used in chromatography for the separation of chemical compounds.
A chromatography column contains the stationary phase and the mobile phase to pass through it. The columns are mostly made of borosilicate glass or acrylic glass.
17. What is difference between Stationary Phase and Mobile Phase?
Stationary phase and mobile phase are two important terms in chromatographic technique. The key difference between stationary and mobile phase is that stationary phase does not move with the sample whereas mobile phase moves with the sample.
18. What is the principle of HPLC?
A sample is injected through the injector in a flow of mobile phase and travels through a stationary phase (column).
The analytes in the sample mixture move with the flow of the mobile phase and interact with the solid support.
The rate of movement relies on the affinity of the analytes toward the stationary phase.
The strongly interacting analytes with the stationary phase travel gradually, while the less interacting compounds elute quickly.
19. What is the principle of Gas Chromatography?
Gas chromatography follows the principle of the partitioning of volatile compounds with the mobile phase (gaseous) and stationary phase (liquid or solid).
The separation speed of molecules through the column is based on the affinity for the stationary phase; the molecules which are partitioned in the gas first come out, whereas the other eluted later.
20. What is the principle of Thin Layer Chromatography (TLC)?
TLC is a separation technique where the molecules of mixtures separate using differential migration through a stationary phase, the solvent mixture flowing through the virtue of capillary forces.
After chromatography is complete, solutes are detected on the surface of a TLC plate by visualizing the reagents and using a UV cabinet.
TLC is a type of planar chromatography, such as paper chromatography, but the stationary phase in TLC is a thin-split Sorbent, which spreads as a thin layer of aluminum, glass, or plastic supporting flat plate.
21. What is the principle of Fluorescence Spectroscopy?
Fluorescence is the emission of light from a molecule, which returns from the lowest vibration level of an excited single state to its normal ground state.
Excited by the molecules, it is achieved by exposing the light source of the specified wavelength.
At what time the molecule/compound is fluorescent, a part of the absorbed light is converted to fluorescence light, an emission of light at a lower wavelength.
22. What is Fluorescence Intensity?
The fluorescence intensity is directly proportional to the concentration of the fluorescent species.
Obviously, the linear relationship among the concentration and the fluorescence intensity falls just to the diluted solution at high concentrations, making it required to first set up a concentration to detect the concentration of a fluorescence graph and unknown sample with known standards.
Fluorometry is used to determine the concentration of fluorophores; it provides sensitive absorption more than the colorimetric method.
23. What Is A Base Line?
Baseline is nothing but the detector's response to the mobile phase. Baseline should be stable to start a run. Unstabilized baseline is called baseline noise.
24. What is System Suitability Test?
Before the start of analysis of the Chromatographic system, like HPLC & GC, system suitability has to be performed to know if the system is working properly or to know its performance.
25. What is Limit of Detection (LOD)?
LOD is the lowest concentration of a substance that can be reliably detected but not necessarily quantified.
26. What is Limit of Quantification (LOQ)?
LOQ is the lowest concentration of a substance that can be reliably detected and accurately quantified.
27. What is OOS?
Out of Specification (OOS) results are those results, generated during testing that do not comply with the relevant specification or standards or with the defined acceptance criteria.
28. What is OOT?
"OOT" stands for Out Of Trend. It means any test results obtained for a particular batch that is markedly different from the results of the batches in a series obtained using the same validated method.
29. What is Q Value in Dissolution?
"Q" represents the targeted amount of active substance, which should be dissolved within a certain time and expressed as a percentage of the label claim.
30. What are the 7 types of dissolution apparatus?
There are seven types of dissolution apparatus in USP:
- Apparatus 1 (baskets)
- Apparatus 2 (paddles)
- Apparatus 3 (reciprocating cylinder)
- Apparatus 4 (flow-through cell)
- Apparatus 5 (paddle over disk)
- Apparatus 6 (rotating cylinder)
- Apparatus 7 (reciprocating disk)