ISO 6571:2008 pdf download – Spices, condiments and herbs – Determination of volatile oil content (hydrodistillation method).
5.2.2 Liquid detergent (used at the concentration recommended by the manufacturer) or a solution of sulfuric acid and potassium dichromate (see the warning) prepared by slowly adding, while stirring continuously, one volume of concentrated sulfuric acid to one volume of saturated potassium dichromate solution and by passing the mixture, after cooling, through a fitted glass filter. WARNING一Avoid any contact of this solution with the skin and mucous membranes. 6 Apparatus Usual laboratory equipment, and in particular the following. 6.1 Distillation apparatus, made of strong glass having a low coefficient of thermal expansion1). The apparatus comprises the following components connected by ground glass joints. 6.1.1 Round-bottom flask, with a ground neck, of capacity 500 ml or 1 000 ml, according to the product concerned (see Annex A). 6.1.2 Condenser system, comprising the following components joined together (see Figure 1): a) a vertical tube (AC), the base of which has a ground joint to fit the flask (6.1.1); b) a bent tube (CDE); c) a vertical bulb condenser (FG); d) an assembly consisting of a tube with a side-arm (K) provided with a ground stopper (K’), a pear-shaped enlargement (J), a tube graduated in divisions of 0,05 ml (JL), a spherical enlargement (L) and a three- way tap (M) connected to the vertical tube (AC) by an inclined tube (O) provided with a safety tube (N), if necessary topped by the steam trap (6.1.3).
Sampling A representative sample should have been sent to the laboratory. It should not have been damaged or changed during transport or storage. Sampling is not part of the method specified in this International Standard. A recommended sampling method is given in ISO 948[1. 8，Procedure NOTE It is intended to specify the test parameters in the Intemnational Standard specifying requirements for each spice or condiment. In the meantime, these parameters are given in Annex A. 8.1 i Preparation of the apparatus Carefully clean the condenser system (6.1.2). Tightly fix the glass stopper (K’) on the side-arm (K) and the steam trap (6.1.3) on the safety tube (N). Turn the apparatus upside down, fill it with the cleaning solution (5.2) and leave it in this position overnight. Rinse the apparatus very carefully with water after having cleaned it.