Report for Analytical Chemists
WHEN IS A "METTLËR" NOT A BALANCE? When it's the Mettler digital thermometer . . . a platinum resistance thermometer that's portable, accurate, easy to use. With features like . . . • all-digital readout from - 4 to + 5 7 5 ° F ( - 2 0 to + 3 0 0 ° C ) , continuous, without range switching • 1 mV/°F recorder output with ± 0 . 1 5 % linearity and full range zero suppression • interchangeable matched platinum resistance sensors • absolute accuracy (including sensor intercharigeability error) from ± 0 . 3 ° F at 32°F to ± . 5 4 ° F at +575°F, ± 0 . 0 5 ° F reproducibility • 0,1°F/digit reading resolution • optional selector switch for six sensors For additional information, write Mettler Instrument Corporation, 20 Nassau Street, Princeton, N.J. 08540
Figure 4. Two types of apparatus for titration utilizing kryptonate as end-point indicator: (a) after Tôlgyessy et al. ( I l ) , (b) after Chleck (17) 1. 2. 3. 4. 5.
Nitrogen supply Regulator and valve Geiger-Muller tube Reaction vessel Buret
6. 7. 8. 9.
Counting cell Proper countsrate meter Flowmeter Magnetic stirrer
other kryptonate chosen. Radioactive kryptonates commonly used in volumetric analysis are listed in Table III.
Mettler Circle No. 80 on Readers' Service Card
Detect, Analyze and Measure
WATER POLLUTION WITH P0LAR0GRAPHY
•
Table III. Radioactive Kryptonated Indicators Radioactive kryptonate of
Substance, detd.
Titrant soin.
Mg
NaOH
HCI
Zn
NaOH;F"
HCI; Th(N03)4
Ag
Ba2+
K 2 Cr 2 0 7
Agi
Nis+
KCN
Agl03
C a 2 + , Mg 2 +, Sr2+
EDTA
Y2(CA)3
Fe 3 +
EDTA
Glass
2+
2
C a , Cd + T h 4 + , H 2 SOi HCI, HNO3
NaF NaOH
Two types of experimental apparatus for radiometric titrations with radioactive kryptonates as end-point indicators are shown in Figure 4.
®
RIVER SAMPLE NO. 1
SAMPLE
specimen groups
to determine presence or absence of anions such as nitrite, nitrates, sulphate and others.
Polarograph of river water showinq copper, nickel and iron concentration at PPM
I D E T L C T a l m o s t every element in the periodic table — singly, or in multiples. RtVER SAMPLE NO. 2 Anodic -— Stripping polarograph showing zinc, lead, a n t i m o n y and copper at concentrations of less than 100 ΡΡΘ.
Send for booklet:
• M E A S U R E quantités to parts-per-million, or even partsper-billion, with anodic stripping.
free
CHEMTRIX, INC.
POLLUTION & POLAROGRAPHY
Instrument for Science P O BCK 725
Bcaverton, Oregon 9/00·)
(b03l 648 1434
Circle No. 20 on Readers' Service Card
ANALYTICAL CHEMISTRY, VOL. 42, NO. 9, AUGUST 1970 ·
21 A
