Tandem Mass Spectroscopy 1. Tandem mass spectroscopy combines which of the following devices? a) Mass spectrometer and gas-solid chromatograph b) Mass spectrometer and gas-liquid chromatograph c) Mass spectrometer and gas chromatograph d) Mass spectrometer and mass spectrometer Answer: d 2. In tandem spectroscopy, the first stage sepatation device is a mass spectrometer. a) True b) False Answer: a 3. Which of the following is used to separate a single mass that is characteristic of a given analyte in a mixture? a) First mass spectrometer b) Second mass spectrometer c) Filter d) Precursor Answer: a 4. The mass-selected ions are activated in which of the following ways that causes them to fall apart to produce product ions? a) Collisional activation b) Evaporational activation c) Inert gas activation d) Thermal activation Answer: a 5. The final MS/MS spectrum consists only of product ions from the selected precursor. a) True b) False Answer: a 6. In reverse-geometry mass spectrometer w

 High Performance Liquid Chromatography(HPLC) high-pressure liquid chromatography, is a technique in analytical chemistry used to separate, identify, and quantify each component in a mixture. Principle  The basic principle of separation by high performance liquid chromatography is similar to classical liquid or column chromatography (LC) though it differs with  regard to the size of the column and the sample. It differs from LC in terms of speed, automation, elution time and individual manual assays of collected fractions. In case of HPLC, microgram amounts of the sample is allowed to pass through a column containing stationary solid inert phase coated with non-volatile liquid phase by means of pressurized flow of a liquid mobile phase where components migrate at different rates due to different relative affinities. Comparison of column size, characteristics of packing material and pressure requirements to force the mobility of mobile phase in classical column chromatography. According

 Magnetic flow meter ( Electromagnetic flow meter) A magnetic flow meter (electromagnetic flow meter) is a transducer that measures fluid flow by the voltage induced across the liquid by its flow through a magnetic field. A magnetic field is applied to the metering tube, which results in a potential difference proportional to the flow velocity perpendicular to the flux lines. The physical principle at work is electromagnetic induction. The magnetic flow meter requires a conducting fluid, for example, water that contains ions, and an electrical insulating pipe surface, for example, a rubber-lined steel tube. Electromagnetic Flow Meters Working Principle Electromagnetic Flow Meters, simply known as mag flow meter is a volumetric flow meter which is ideally used for waste water applications and other applications that experience low pressure drop and with appropriate liquid conductivity required. The device doesn’t have any moving parts and cannot work with hydrocarbons and distilled wate

  Ultrasonic flow meter An ultrasonic flow meter can be defined as, a meter that is used to measure liquid velocity with ultrasound to analyze the volume of liquid flow.  Ultrasonic Flow Meters Working Principle Ultrasonic flow meters calculate the flow rate by utilizing the speed of sound through a fluid created by transducers mounted to the pipe wall. There are two types of ultrasonic meters: Doppler and Time-of-Flight. The Doppler ultrasonic meter requires particles in the fluid to reflect sound waves back to the pipe wall transducers. The difference in frequency between the sent and reflected wave is proportional to fluid velocity. The Time-of-Flight ultrasonic meter requires a clean fluid and works by using opposing transducers mounted to transmit/receive sound waves at an angle across the pipe. The difference in the time required to send a pulse along the path between transducers in the direction of flow vs. against the flow is proportional to the fluid velocity. Some models u

  Thermal mass flow meter Thermal mass flow meters are designed to accurately monitor and measure mass flow (as opposed to measuring volumetric flow) of clean gases, a parameter that is not temperature dependent. Therefore, the thermal mass flow meter does not require a correction for changes in gas temperature, pressure, viscosity and density. Thermal Mass Flow meter Working Principle The thermal mass meter measures gas flow based on the concept of convective heat transfer. The flow meters are available in either inline flow bodies or insertion-style. In either case, the meter’s probe inserts into a gas stream of a pipe, stack or duct. Toward the tip of the meter’s probe are two sensors. These sensors are resistance temperature detectors (RTDs) or resistance thermometers and measure temperature. The RTDs consist of durable reference-grade platinum windings clad in a protective 316 SS or Hastelloy C sheath. One of the RTDs is heated by an integrated circuit and functions as the flow se

  Orifice  flow meter An orifice in a pipeline is shown in below figure with a manometer for measuring the drop in pressure (differential) as the fluid passes thru the orifice. The minimum cross sectional area of the jet is known as the “vena contracta.” How does it work? As the fluid approaches the orifice the pressure increases slightly and then drops suddenly as the orifice is passed. It continues to drop until the “vena-contracta” is reached and then gradually increases until at approximately 5 to 8 diameters downstream a maximum pressure point is reached that will be lower than the pressure upstream of the orifice. The decrease in pressure as the fluid passes thru the orifice is a result of the increased velocity of the gas passing thru the reduced area of the orifice. When the velocity decreases as the fluid leaves the orifice the pressure increases and tends to return to its original level. All of the pressure loss is not recovered because of friction and turbulence losses in th

  Turbine flow meter A turbine flow meter is used for volumetric total flow and/or flow rate measurement and has a relatively simple working principle. As fluid flows through the turbine meter, it impinges upon turbine blades that are free to rotate about an axis along the center line of the turbine housing.  Turbine flow meters use the mechanical energy of the liquid to rotate a rotor within the flow stream. The rotational speed is directly proportional to the velocity of the fluid traveling through the meter. These meters are used in multiple industries to reliably measure liquids, gases and vapors. Introduction Turbine flow meters are used to measure clean, dry gases and liquids such as hydrocarbons, chemicals, gases and vapors, fuels and other types of liquids with lower viscosity, and for applications requiring highly accurate and precise measurements. These turbine flow meters are mostly used for military applications. They are also used in blending systems in the petroleum indus