OIL CONTENT OF OLIVE RESIDUE
APPARATUS
- SUITABLE EXTRACTION APPARATUS FITTED WITH A 200 TO 250 ML ROUND-BOTTOMED FLASK ,
- ELECTRICALLY HEATED BATH ( E.G . , SAND BATH , WATER BATH ) OR HOTPLATE ,
- ANALYTICAL BALANCE ,
- OVEN REGULATED TO A MAXIMUM OF 80 * C ,
- ELECTRICALLY HEATED OVEN FITTED WITH A THERMOSTATIC DEVICE REGULATED TO 103 MORE OR LESS 2 * C AND ONE THAT CAN BE SWEPT WITH A STREAM OF AIR OR OPERATED AT REDUCED PRESSURE ,
- MECHANICAL MILL , EASY TO CLEAN , AND ONE THAT ALLOWS THE OLIVE RESIDUES TO BE GROUND WITHOUT A RISE IN THEIR TEMPERATURE OR ANY APPRECIABLE ALTERATION IN THEIR CONTENT OF MOISTURE , VOLATILE MATTER OR SUBSTANCES EXTRACTABLE WITH HEXANE ,
- EXTRACTION THIMBLE AND COTTON WOOL OR FILTER PAPER FROM WHICH SUBSTANCES EXTRACTABLE WITH HEXANE HAVE ALREADY BEEN REMOVED ,
- DESSICATOR ,
- SIEVE WITH 1 MM DIAMETER APERTURES ,
- SMALL PARTICLES OF PREVIOUSLY DRIED PUMICE STONE .
REAGENT
NORMAL HEXANE , TECHNICAL GRADE , WHICH MUST LEAVE A RESIDUE OF LESS THAN 0,002 G PER 100 ML , ON COMPLETE EVAPORATION .
PROCEDURE
PREPARATION OF THE TEST SAMPLE
IF NECESSARY , USE THE MECHANICAL MILL , WHICH HAS PREVIOUSLY BEEN PROPERLY CLEANED , TO GRIND THE LABORATORY SAMPLE IN ORDER TO REDUCE IT TO PARTICLES THAT CAN PASS COMPLETELY THROUGH THE SIEVE .
USE ABOUT ONE TWENTIETH OF THE SAMPLE TO COMPLETE THE PROCESS OF CLEANING THE MILL , DISCARD THE GROUND MATERIAL , GRIND THE REMAINDER AND COLLECT , MIX CAREFULLY AND ANALYZE WITHOUT DELAY .
TEST PORTION
AS SOON AS THE GRINDING OPERATION HAS BEEN COMPLETED , WEIGH OUT ABOUT 10 G OF THE SAMPLE TO THE NEAREST 0,01 G FOR TESTING .
PREPARATION OF THE EXTRACTION THIMBLE
PLACE THE TEST PORTION IN THE THIMBLE AND PLUG WITH COTTON WOOL . IF A FILTER PAPER IS USED , ENVELOPE THE TEST PORTION IN IT .
PRELIMINARY DRYING
IF THE OLIVE RESIDUES ARE VERY MOIST ( I.E . , MOISTURE AND VOLATILE MATTER CONTENT MORE THAN 10 % ) , CARRY OUT PRELIMINARY DRYING BY PLACING THE LOADED THIMBLE ( OR FILTER PAPER ) IN THE OVEN HEATED FOR AN APPROPRIATE TIME AT NOT MORE THAN 80 * C IN ORDER TO REDUCE THE MOISTURE AND VOLATILE MATTER CONTENT TO LESS THAN 10 % .
PREPARATION OF THE ROUND-BOTTOMED FLASK
WEIGH TO THE NEAREST 1 MG THE FLASK CONTAINING ONE OR TWO PARTICLES OF PUMICE STONE , PREVIOUSLY DRIED IN THE STOVE AT 103 MORE OR LESS 2 * C AND THEN COOLED IN A DESSICATOR FOR NOT LESS THAN ONE HOUR .
INITIAL EXTRACTION
INTO THE EXTRACTION APPARATUS INSERT THE THIMBLE ( OR FILTER PAPER ) CONTAINING THE TEST PORTION . POUR INTO THE FLASK THE REQUISITE QUANTITY OF HEXANE . FIT THE FLASK TO THE EXTRACTION APPARATUS AND PLACE THE WHOLE ON THE ELECTRICALLY HEATED BATH . ADJUST THE RATE OF HEATING IN SUCH A