Quantitative determination of metals

Claim 1

A METHOD OF VOLUMETRICALLY DETERMINING METAL CATIONS IN SOLUTION WHICH COMPRISES MIXING A MEASURED VOLUME OF THE SOLUTION CONTAINING THE METAL CATIONS AND A SOLUTION CONTAINING AN AMINO POLYCARBOXYLIC ACID COMPOUND IN AT LEAST AN AMOUNT SUFFICIENT TO SEQUESTER ALL OF THE AFORESAID METAL CATIONS, SAID COMPOUND HAVING IN RELATION TO ONE BASIC NITROGEN ATOM MORE THAN ONE CARBOXYMETHYL GROUP DIRECTLY ATTACHED THERETO, THE PH VALUE OF BOTH SOLUTIONS HAVING BEEN PREVIOUSLY ADJUSTED TO THE SAME LEVEL, TITRATING THE RESULTANT SOLUTION MIXTURE WITH AN ALKALINE SOLUTION OF KNOWN STRENGTH IN SUFFICIENT AMOUNT TO RESOTRE THE PH VALUE OF THE RESULTANT SOLUTION MIXTURE TO THAT OF THE ORIGINAL SOLUTIONS IMMEDIATELY PRIOR TO THE MIXING THEREOF, THE AMOUNT OF ALKALINE SOLUTION BEING A DIRECT MEASURE OF THE AMOUNT OF THE AFORESAID METAL CATIONS PRESENT IN THE ORGINAL SOLUTION.

Claim 2

A METHOD OF VOLUMETRICALLY DETERMINING METAL CATIONS IN SOLUTION WHICH COMPRISES MIXING A MEASURED VOLUME OF THE SOLUTION CONTAINING THE METAL CATIONS AND A SOLUTION CONTAINING AN AMINO POLYCARBOXYLIC ACID COMPOUND IN AT LEAST AN AMOUNT SUFFICIENT TO SEQUESTER ALL OF THE AFORESAID METAL CATIONS, SAID COMPOUND HAVING IN RELATION TO ONE BASIC NITROGEN ATOM MORE THAN ONE CARBOXYMETHYL GROUP DIRECTLY ATTACHED THERETO, THE PH VALUE OF BOTH SOLUTIONS HAVING BEEN PREVIOUSLY ADJUSTED TO THE SAME LEVEL, TITRATING THE RESULTANT SOLUTION MIXTURE WITH AN ALKALINE SOLUTION OF KNOWN STRENGTH IN SUFFICIENT AMOUNT TO RESOTRE THE PH VALUE OF THE RESULTANT SOLUTION MIXTURE TO THAT OF THE ORIGINAL SOLUTIONS IMMEDIATELY PRIOR TO THE MIXING THEREOF, THE AMOUNT OF ALKALINE SOLUTION BEING A DIRECT MEASURE OF THE AMOUNT OF THE AFORESAID METAL CATIONS PRESENT IN THE ORGINAL SOLUTION.