<human>:  Why is it called High Performance Liquid Chromatography?
<bot>: It’s called High Performance because it’s a very fast and accurate way to separate molecules. It is liquid chromatography because the molecules are separated using a liquid called a mobile phase. The mobile phase is pumped through a tube that is filled with tiny beads of silica gel. The beads are coated with a special chemical that binds to the molecules you are trying to separate. The molecules are pulled along the tube by a high-speed pump. The pump is connected to a detector, which measures the amount of light that passes through the tube.