zeio. The boron blank which previously was attributed t o boron contamination of reagents was shown actualiy to be a salt elution of boron from the resins. Expressing the salt content of the blood ash solution sample< used in terms of milliequivalents of sodium chloride and using the slope of tlic line in Figure 1, the calculated amount of boron eluted b y such samples is 0.97 y of boron. The close agrccnient nith the experimental value of 0.9 y of boion is perhaps a fortunate occurrencc. but is nevertheless ncll within cupcriniental error and of the propcr orrlcr i f magnitude.
Table
Wt. of Steel, Gram
Determination of Boron in National Bureau of Standard Steels
Boron, y Present Resin blank
-_
.-
Found7
I3oron, TC
SBS Steel S o . 51, 0.0027% Boron 0 5000 0.5000
1
0 1349
DISCUSSION OF RESULTS
l‘hic work establishes the fact that thil mixed resin bed ion exchange procedure as originally proposed for the separation of milligram quantities of boron provides recovery of boron well within limits of titrimetric analytical procedures, using a fully repeneratctl anion exchange resin as obtained from the nimufacturer in the free h s e form. Rcqcntation and re-use of m . h rriins are not recommended, although tlic exact rimon why such fully reqcm’iatcd rrsiiiq will retain small amountq of boron has not becn clearly t-t:ihlished. The separatory procedwe, :is applie(1 t
