FIRST IN ORION'S NEW SERIES OF CHEMICAL SENSING ELECTRODES
now-measure calcium ion activity directly with any expanded scale pH meter Number One in a series of specific ion electrodes, the Calcium Activity electrode from Orion Research Incor porated is the first major advance in potentiometric electrochemistry since the glass electrode. This electrode makes possible, for the first time, direct rapid continu ous measurement of calcium ion ac tivity in aqueous solutions.
AVAILABILITY The Orion Calcium Activity electrode is priced at $145.00 and is available from major laboratory supply dealers. It is supplied as a kit with complete instructions, ion exchange and refer ence solutions, porous membranes, andall necessary handling equipment. MV. +120-
In applications where concentration measurement is required the elec trode makes an ideal endpoint de tector for EDTA.
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+100-
INSTRUMENTATION Required instrumentation: any mod ern expanded scale pH meter or millivolt electrometer and a con ventional saturated KCI reference electrode. Technique is similar to that of simple pH measurement.
10-1M CaCI2
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+80-
SELECTIVITY The electrode is extremely selective for calcium ion. Measurement of a millimolar calcium solution can be made with negligible error due to the presence of a 100-fold excess of so dium or potassium. The electrode is at least 50 times more sensitive to calcium than magnesium.
ELECTRODE POTENTIAL vs. pH \
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10-2M CaClz ^—'**~
\\
+60-
\ \
10-3M CaCli
V
\Y\ 5xl(HM NaCl \ \ * • — — — — — —— — — — — — — \ j f r 2 M g C J 2 — lt>4M CaC|
+40-
—i—i 2 4
1
1 1 • ι 6 8 SOLUTION pH
Ρ 10
1
rP H 12
CONDENSED SPECIFICATIONS Concentration range: from saturated calcium solutions to 10-5 m/1. pH range: 5.5 to 11 pH Temperature range: 0 to 50° C. Electrical resistance: 25 megohms at 25° C.
Use this coupon to request complete product literature or an electrode for evaluation. Π Please send a copy of the Calcium Activity Electrode bulletin. •
Please arrange a demonstration through my laboratory supply dealer.
Name Organization
,
Street City WATCH FOR MORE SPECIFIC-ION ELECTRODES FROM ORION
State
ZIP
Laboratory Supply Dealer
ORION RESEARCH INCORPORATED 11 Blackstone St., Cambridge, Massachusetts 02139/(617) UN 4-5400 Circle No. 71 on Readers' Service Card
VOL.
38, NO. 7, JUNE 1966
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35 A