COEI-2-ZINC Determination of zinc by atomic absorption spectrometry

1. Principle

The zinc is determined directly by atomic absorption spectrometry by flame.

2. Apparatus

Instrumental parameters: (given as an example)

COEI-2-VISCPE Determination of the ability of an enzymatic preparation to interrupt pectic chains by measuring viscosity

1. Principle

Here, it is proposed to measure the quantity of enzyme needed to halve the viscosity of a standard solution with a given pH, temperature and time.

COEI-2-TANTAL Tantalisation of platforms of l’Vov in graphite

1. Preparation of tantalum solution at 6% (m/v) according to the zatka process

Three grammes of tantalum powder are put in a 100 ml Teflon  cylindrical vase.

Add 10 ml of hydrofluoric acid diluted to a half, 3 g of dehydrated oxalic acid and 0.5 ml of hydrogen peroxide at 30 vol.

Heat carefully to dissolve the metal.

COEI-2-SULFAT Search for sulphates

In a 160  16 mm test tube, place the volume prescribed of the solution obtained by the means indicated in each monography; add 1 ml of diluted hydrochloric acid (R); adjust to 20 ml with water and add 2 ml of barium chloride solution at 10% (R).

COEI-2-SODIUM Determination of sodium by absorption atomic spectrometry

1. Principle

The sodium is determined after mineralisation by dry process by atomic absorption spectrometry.

The addition of a spectral buffer (cesium chloride) to avoid ionisation of sodium is necessary.

COEI-2-SUCSAC Grape sugar: Determination of saccharose by HPLC

1. Principle

The samples diluted or put in solution are analysed by high performance liquid chromatography: Separation on column of grafted silica NH₂ and detection using a differential refractometer.

COEI-2-POTASS Determination of potassium by atomic absorption spectrometry

1. Principle

The potassium is determined by mineralisation by dry process by atomic absorption spectrometry.

The addition of a spectral buffer (cesium chloride) to avoid the ionisation of the potassium is necessary.

COEI-2-PLOMB Determination of lead by atomic absorption spectrometry

1. Principle

After mineralisation of the sample in an acid medium, the lead is determined by spectrometry without flame (electro-thermal atomisation).