What is chromatography used for BBC Bitesize?

Separating dissolved solids – chromatography Paper chromatography is a method for separating dissolved substances from one another. It is often used when the dissolved substances are coloured, such as inks, food colourings and plant dyes.

How does chromatography work Bitesize?

A spot of the mixture is placed near the bottom of a piece of chromatography paper. The paper is then placed upright in a suitable solvent , such as water. As the solvent soaks up the paper, it carries the mixtures with it. Different components of the mixture will move at different rates.

How chromatography works simple explanation?

Chromatography works by passing the dissolved material, liquid or gas through a filter material. The molecules separate into layers as the molecules pass through the filter. The mechanism of separation depends on the filtering method, which is determined by the kinds of molecules to be separated.

How does distillation work BBC Bitesize?

Distillation is a separation technique used to separate liquid (the solvent) from a mixture and keep the liquid part. Distillation involves boiling the solution and then condensing the vapour back into a liquid by cooling it down. For example, dirty water can be distilled to produce pure water, which is safe to drink.

What is evaporation BBC Bitesize?

Evaporation describes the process of a liquid turning into a gas. Evaporation is a slower process than boiling because it occurs at temperatures below the boiling point of the liquid. Evaporation occurs at all temperatures, boiling happens at a fixed temperature depending on the liquid.

Why does carotene travel faster on chromatography paper?

A small sample of plant pigment placed on chromatography paper travels up the paper due to capillary action. Beta carotene is carried the furthest because it is highly soluble in the solvent and because tit forms no hydrogen bonds with the chromatography paper fibers.

Why PDA detector is used in HPLC?

Diode-Array Detection (DAD) or Photodiode-Array Detection (PDA) is an analytical technique that can be used to determine the purity of an analyte or related impurity peak eluting during an HPLC separation.

What is the principle of paper chromatography?

Paper chromatography is used to separate mixtures of soluble substances. These are often coloured substances such as food colourings, inks, dyes or plant pigments. 1. Water and ethanol solution is heated 2. As the paper is lowered into the solvent, some of the dye spreads up the paper 3.

How many spots will a pure substance produce during paper chromatography?

A pure substance will only produce one spot on the chromatogram during paper chromatography. Two substances will be the same if they produce the same colour of spot, and their spots travel the same distance up the paper. In the example below, red, blue and yellow are three pure substances. The sample on the left is a mixture of all three.

How is simple chromatography used to separate mixtures?

Chromatography can be used to separate mixtures of coloured compounds. Mixtures that are suitable for separation by chromatography include inks, dyes and colouring agents in food. Simple chromatography is carried out on paper. A spot of the mixture is placed near the bottom of a piece of chromatography paper.

What is colourless chromatography and how can it be done?

Chromatography can also be done when the different substances in the mixture are colourless. The chromatogram can be exposed to a locating agent, which reacts with the invisible chemicals so that they can be seen.