10+ Metalman Auto Interview Questions and Answers

HPLC is a technique used to separate, identify, and quantify components in a mixture. Chromatography is a method to separate components.

• HPLC is advantageous as it can separate complex mixtures with high resolution and sensitivity.

• It is used in pharmaceuticals, food and beverage, environmental analysis, and forensic science.

• Chromatography is a technique used to separate components based on their physical and chemical properties.

• Types of chromatography include gas chromatograph...read more

HPLC is a chromatographic technique used to separate, identify, and quantify components in a mixture.

• HPLC works by pumping a liquid sample mixture through a column packed with stationary phase material.

• The components in the mixture interact differently with the stationary phase, causing them to separate and elute at different times.

• The eluted components are detected by a detector and recorded as a chromatogram.

• HPLC is commonly used in pharmaceuticals, food analysis, and envir...read more

Detectors used in gas chromatography include FID, TCD, ECD, NPD, and MS.

• Flame Ionization Detector (FID) is used for organic compounds

• Thermal Conductivity Detector (TCD) is used for inorganic compounds

• Electron Capture Detector (ECD) is used for halogenated compounds

• Nitrogen-Phosphorus Detector (NPD) is used for nitrogen and phosphorus-containing compounds

• Mass Spectrometry (MS) is used for identifying unknown compounds

Conductivity detector is commonly used in ion chromatography.

• Conductivity detector measures the ability of ions to conduct electricity.

• It is used in ion chromatography to detect and quantify ions in a sample.

• It is particularly useful for analyzing inorganic ions such as anions and cations.

• Examples of applications include water quality testing, food and beverage analysis, and pharmaceutical analysis.

pH is a measure of acidity or alkalinity of a solution. It ranges from 0 to 14.

• pH stands for 'potential of hydrogen'

• A pH of 7 is considered neutral, below 7 is acidic, and above 7 is alkaline

• Each whole pH value below 7 is ten times more acidic than the next higher value

• Each whole pH value above 7 is ten times more alkaline than the next lower value

Acid is a substance that donates hydrogen ions, while base is a substance that accepts hydrogen ions. The pH scale ranges from 0-14.

• Acids have a pH below 7, while bases have a pH above 7.

• Acids taste sour and can corrode metals, while bases taste bitter and feel slippery.

• Examples of acids include vinegar, lemon juice, and battery acid, while examples of bases include soap, bleach, and ammonia.

Thermal conductivity detectors (TCD) and Flame ionization detectors (FID) are bulky in gas chromatography.

• TCD and FID are commonly used detectors in gas chromatography

• TCD measures thermal conductivity of the sample while FID measures ionization of the sample

• Both detectors require bulky components such as a flame or a filament

• Other detectors such as mass spectrometry (MS) or electron capture detector (ECD) are less bulky

UV-visible range is the range of electromagnetic radiation that is visible to the human eye.

• The UV-visible range is typically between 200-800 nanometers.

• UV radiation has a shorter wavelength and higher energy than visible light.

• Examples of UV-visible range applications include spectroscopy and photolithography.

• UV radiation can be harmful to human skin and eyes.

• Visible light is the portion of the UV-visible range that is visible to the human eye.

Ion chromatography is a technique used to separate and analyze ions in a sample. Resin is a solid material used in the process to exchange ions.

• Ion chromatography separates ions based on their charge and affinity for the stationary phase

• Resin is a solid material with charged functional groups that exchange ions with the sample

• Examples of applications include analyzing water quality, food and beverage testing, and pharmaceutical analysis

Gas chromatography is a technique used to separate and analyze volatile compounds in a mixture.

• It involves injecting a sample into a column filled with a stationary phase and a carrier gas.

• The compounds in the sample interact differently with the stationary phase and are separated as they travel through the column.

• The separated compounds are detected and identified based on their retention time and other properties.

• Advantages include high sensitivity, selectivity, and the abi...read more

The normal range of pH is between 7.35 and 7.45.

• pH is a measure of acidity or alkalinity of a solution.

• A pH of 7 is considered neutral, below 7 is acidic, and above 7 is alkaline.

• The normal pH range of human blood is tightly regulated between 7.35 and 7.45.

• Changes in pH can have significant effects on biological processes and can lead to health problems.

UV-Vis detector, fluorescence detector, refractive index detector, evaporative light scattering detector are commonly used in HPLC.

• UV-Vis detector measures the absorbance of light by the sample

• Fluorescence detector measures the fluorescence emitted by the sample

• Refractive index detector measures the change in refractive index of the mobile phase

• Evaporative light scattering detector measures the scattering of light by the sample

UV spectroscopy is based on the principle that molecules absorb ultraviolet or visible light to excite their electrons to higher energy levels.

• UV spectroscopy measures the absorption of light in the UV or visible region of the electromagnetic spectrum.

• The amount of light absorbed is proportional to the concentration of the absorbing species.

• UV spectroscopy is used to determine the concentration of a substance in a sample, identify functional groups, and study reaction kinetic...read more

Normality is the concentration of a solution expressed as the number of equivalents of solute per liter of solution. Molality is the concentration of a solution expressed as the number of moles of solute per kilogram of solvent.

• Normality is a measure of the number of reactive species in a solution.

• It is expressed in terms of equivalents per liter of solution.

• Molality is a measure of the concentration of a solution in terms of the number of moles of solute per kilogram of solv...read more

Various detectors are used in HPLC such as UV-Vis, fluorescence, refractive index, evaporative light scattering, and electrochemical detectors.

• UV-Vis detector is the most commonly used detector in HPLC

• Fluorescence detector is used for compounds that have natural fluorescence

• Refractive index detector is used for compounds that do not absorb UV light

• Evaporative light scattering detector is used for non-volatile compounds

• Electrochemical detector is used for compounds that are el...read more

IR spectroscopy is based on the principle of absorption of infrared radiation by molecules.

• IR spectroscopy measures the vibrations of molecules in the infrared region of the electromagnetic spectrum.

• Different functional groups absorb at different frequencies, allowing for identification of compounds.

• IR spectra can be used to determine the presence of impurities or contaminants in a sample.

• IR spectroscopy is widely used in chemistry, biochemistry, and materials science.

Oxidation is the loss of electrons, while reduction is the gain of electrons.

• Oxidation involves the addition of oxygen or the removal of hydrogen from a molecule.

• Reduction involves the addition of hydrogen or the removal of oxygen from a molecule.

• Oxidation and reduction always occur together in a chemical reaction, known as a redox reaction.

• Examples of redox reactions include combustion, rusting, and photosynthesis.

There are two types of ion chromatography: cation exchange chromatography and anion exchange chromatography.

• Cation exchange chromatography separates positively charged ions based on their affinity for negatively charged resin.

• Anion exchange chromatography separates negatively charged ions based on their affinity for positively charged resin.

• Both types of ion chromatography use a mobile phase and a stationary phase to separate ions.

• Ion chromatography is commonly used in enviro...read more