TRAVISTRA

 HIGH-PERFORMANCE LIQUID CHROMATOGRAPHY It is a method used for the separation, purification, and identification of various nonvolatile high molecular weight organic compounds and natural products like cholesterol, terpenoids. ADVANTAGES High-speed separation Excellent column separation Solvent consumption is minimum Sensitive and accurate Separation can be done at an ambient temperature. PRINCIPLE The components of the mixture are separated depending upon the extent of adsorption and partition on the stationary phase and the rate at which the component is carried by the mobile phase. The mobile phase is liquid and the stationary phase can be solid or liquid. INSTRUMENTATION Solvent reservoirs are used to collect the different solvents. Pressure pump to apply pressure  Sample injector to give the mixture which is to be separated in the analytical column Regulator to adjust the flow rate Guard column to remove the particulate matter and contaminants from the solvent. The analyt...

 THIN LAYER CHROMATOGRAPHY It is a chromatographic separation method used to separate mixtures, to check the purity of a mixture, and to monitor the progress of the reaction. Procedure A glass plate coated with a material of the adsorbent will constitute the stationary phase. The material is made into a slurry or a paste and the glass plate is coated with it by a thin layer applicator and dried. This glass plate with a thin layer of stationary phase is called chromatoplate. The mixture to be separated is applied to one end of the plate and it is placed in the solvent. When the solvent reaches near the top, it is removed and dried. If the components are colored the spots can be readily located. If the components are colorless the dried plate is sprayed with a suitable reagent to make the spot colored. In this way, the position of the components is located and their Rf values are determined. Rf value is the ratio of the distance traveled by a component to the distance traveled by the...

 COLUMN CHROMATOGRAPHY It is a technique in which the stationary phase is solid or a liquid supported by a solid. When a column is used as the adsorbent it is called adsorption column chromatography. When the solid column is acting only as a support to the liquid adsorbent then it is called partition column chromatography. SEPARATION The selection of solvent is based on the nature of the components in the mixture. Adsorption depends upon the nature of the solvent and the adsorbent.  The rate at which the components of a mixture are separated depends upon the activity of the adsorbent and the polarity of the solvent. If the activity of the adsorbent is very high and polarity is low, then separation is low but gives good separation. If the activity of the adsorbent is low and the polarity of the solvent is high, then the separation is rapid but gives poor separation PROCEDURE A proper adsorbent is selected and made a slurry with a suitable liquid and placed in a suitable tube wh...

CHROMATOGRAPHY  It is a method used for the separation, purification, and identification of a mixture of substances. It is useful when components of a mixture have similar physical and chemical properties and hence cannot be separated by other methods. Principle: It is based on the distribution of the components in a mixture between a stationary and a mobile phase. The stationary phase may be a column of adsorbent, a paper, a thin layer of adsorbent through which the mobile phase moves on. The mobile phase may be a liquid or gas. The principle of chromatographic separation is always adsorption (absorption of a constituent on the surface of the solid stationary phase) or partition (distribution of a constituent in between two liquid stationary phases). THEORY OF CHROMATOGRAPHY The separation takes place due to the differential migration of components which depends on the relative affinity towards the stationary and mobile phases.  The component which is less strongly held by th...

 DIFFERENTIAL THERMAL ANALYTICS  It is a thermal analytic technique that can be used as a fingerprint for the identification of different materials like clays, minerals, cement, etc. DTA allows the detection of every chemical and physical change whether or not it is accompanied y a change in weight. In DTA, the temperature of the samples and a thermally inert reference material are measured as a function of temperature. The differential temperature (∆T) vs the programmed temperature (T) gives the temperature at which the transition occurs and whether the transition is exothermic or endothermic.

 THERMOGRAVIMETRIC ANALYSIS It is a thermal analytic technique in which the mass of a substance is measured as a function of increasing temperature. As the temperature increases, the sample undergoes physical and chemically changed will be accompanied by mass loss.  It is used to determine a material’s thermal stability and its fraction of volatile components by measuring the weight change.  It is carried out in air or inert atmosphere such as nitrogen, helium, or Argon.  The graph obtained is known as a thermogram. It is a plot of mass vs temperature. It can provide information about physical phenomena such as vaporization, sublimation. Absorption, adsorption, and desorption. And chemical phenomena like chemisorption, dehydration, decomposition, oxidation, and reduction.  WORKING OF TGA The sample is placed in a crucible or shallow dish that is attached to an automatic recording balance and is continuously heated by the power source. The weight change of the sa...