eChapters

Mass spectrometry (MS) is a powerful and versatile analytical technique through which mass of an atom, or a molecule is assessed. It helps for identification and structure elucidation of various complex compounds. The instrument used is known as Mass Spectrometer. It serves the purpose of qualitative identification, confirmation as well as the quantification of an atom or a molecule. MS identification is conclusive because the mass spectrum of each substance is unique. In general, MS instruments are composed of a sample inlet, an ionization source, a molecule accelerator, a detector, an amplifier, and a recorder (Figure 7.1)

Interaction of radiant energy, exhibiting the properties of both waves and particles, with matter is dealt in spectroscopy. Matter may be defined as material, existing in solid or liquid or gaseous phase, which is composed of molecules, atoms, or ions. Atoms, molecules, and ions, irrespective of their physical state, remain in constant motion in a matter. Molecules may rotate, vibrate, and move from place to place in space. While radiant energy interacts with matter, these molecular motions are influenced to some extent. It is observed that radiations from ultraviolet and visible range of electromagnetic spectrum lead to the movement of bonding electrons from lowest energy state (ground state) to higher energy state (excited state) in the molecules, while absorption of IR radiation causes the molecule to vibrate more. Such changes, referred to as transition, are responsible for changing the molecular energy level.

Electrophoresis is an important separation technique for the charged molecules. Biologically important molecules, such as amino acids, peptides, proteins nucleotides, nucleic acids which carry electrical charge as they possess certain ionizable functional groups may be separated and identified from a mixture with the help of this technique. Some compounds that are non-polar in nature and do not possess any charge may be transformed to charge carrying derivatives. Thus, phosphate derivatives of carbohydrates may be separated and characterized utilizing electrophoretic techniques.

Centrifugation is a technique that promotes accelerated settling of particles in a solid-liquid mixture by the application of centrifugal force. The device that accelerates the separation with the help of centrifugal force is known as ‘Centrifuge’. The centrifuge consists of a fixed base or frame and a rotating part in which the mixture is placed and is then spun at high speed.

Indicators are the natural or synthetic chemical compounds that are used to detect the equivalence point in a volumetric analysis where unknown compound in a solution form is quantitatively estimated with the help of a known standard solution. The equivalence point, also known as the stoichiometric end point, is the point or stage of a titration reaction where the equivalent amount of the reacting substances are mixed together, and this point is identified by monitoring the rate of change in pH, conductivity, flow of current, adsorption, fluorescence, changing of solution colour, occurrence or disappearance of turbidity, flocculation or deflocculation, etc.

Volumetric analysis, also known as titrimetric analysis, is an analytical method of estimating the concentration of a known solute (analyte) in a solution by measuring the volume of a second known solution of known concentration (standard solution), that reacts completely with the known solute of unknown concentration. The prerequisite of titration is that the two different analytes, present in solution form, must involve in a fast chemical reaction. The standard solution is more commonly known as ‘titrant’ and the solution whose concentration needs to be determined is frequently called ‘titrand’.

Acids are chemical substances that are sour in taste and highly corrosive. The term ‘Acid’ was derived from a Latin word ‘acidus’, meaning ‘sour’. They emit sharp odour and transform litmus colour from blue to red. They lose their properties when alkalis are added to them. However, in this process, alkalis also lose their alkaline properties.

Technical Term                                 Definition

Geographical Information System

Base Map                                          Basic representation of a region of the earth as it would appear if viewed from above. That is a map containing geographic

                                                          features that is used for reference. Roads, for example, are commonly found on base maps

Technical Term              Definition

Land Use Capability     Capability is the inherent capacity of land to perform given at a level for a general use

Technical Term                    Definition

Canal Irrigation System      The system in which irrigation water is supplied through irrigation canals network (main canal, submain canal, distributaries, and

                                            minors) from source of water (reservoirs) to point of application (agricultural lands)

Technical Term           Definition

Fluid Mechanics         Fluid Mechanics is a study of physical behavior of fluids and fluid systems, and laws governing their behavior. It incorporates action of forces

                                   on fluids and the resulting flow pattern

Technical Term                            Definition

Geomorphological Analysis       Geomorphological analysis is the systematic description of watershedís geometry and its stream channel system to measure

                                                   the liner aspects of drainage network, aerial aspects of drainage basin and relief aspects of channel network.

Technical Term          Definition

Soil                             Soil is the superficial unconsolidated and usually weathered part of the mantle of a planet and especially of the earth

Technical Term      Definition

Drainage               Removal and disposal of excess water from agricultural lands is referred as drainage.

Technical Term       Definition

Groundwater         Water present in the zone of saturation (below water table) is called groundwater

Technical Term            Definition

Infiltration                    Infiltration is movement of water from the surface into the soil or ground.

Technical Term                        Definition

Hydrology                               Hydrology is the science of water derived from Greek wordî hydro + logosî i.e., water + sciences and hance defined as the science which deals with occurrence, distribution and circulation of atmospheric water through unending Hydrologic cycle.

Overview of Soil Erosion Conservation Measures

Technical Term           Definition

Soil erosion                Transportation & deposition of soil particles from one place to other after detachment from soil mass.

 1. A mineral that forms an original component of rock is called

a. Primary         b. Secondary

c. Essential         d. Accessory