REPORT
WHY USE AUTOMATIC ON-STREAM COLORIMETRIC ANALYZERS Benefits in precise, continuous control; sharper operating efficiency; a n d reduction in boiler m a i n t e n a n c e — a r e so g r e a t t h a t few p l a n t s can afford t o overlook a u t o m a t i c on-stream analyses. Especially since Milton R o y Colorimetric Analyzers now provide effective, 'roundthe-clock, a u t o m a t i c supervision a t a realistic price. WHERE AUTOMATIC ANALYZERS ARE USED. Demineralizing syst e m s , boiler feedwater m a k e u p , boiler water, condensate a n d cooling w a t e r are p r i m e c a n d i d a t e s for a u t o m a t i c analysis. Critical operating pressures a n d t e m p e r a t u r e s in t h e m o d e r n power p l a n t emphasize t h e need for b o t h w a t e r a n d s t e a m p u r i t y . I m p u r i t i e s , often in t h e parts-per-billion range, m u s t be detected a n d corrected w i t h o u t delay t o p r e v e n t serious trouble. T h e only a l t e r n a t i v e is costly a n d often i n a d e q u a t e m a n u a l analysis, which is seldom fast enough or frequent enough t o keep u p w i t h t h e changes in operating conditions. M i l t o n R o y A u t o m a t i c Colorimetric Analyzers offer precise, continuous analysis combined w i t h economy. B o t h t h e Q U A N T I C H E M ® and the C H E M A L Y Z E R ® made by Milton Roy, are priced realistically. H e r e ' s proof of dollars a n d cents savings. HOW AUTOMATIC ANALYZERS REDUCE COSTS. One c o m p a n y using a Chemalyzer to m o n i t o r t o t a l hardness in t h e effluent of a softener reports t h a t boiler cleanings h a v e been c u t in half . . . from once i n two years t o once in four years. W i t h chemical cleaning r u n n i n g t o $2,000 t o $3,000 per boiler, direct savings h a v e m o r e t h a n paid for t h e unit. A n o t h e r c o m p a n y , also using a Chemalyzer t o analyze hardness i n boiler feedwater, e s t i m a t e s t h a t t h e y save $2500 a y e a r in labor costs alone a n d a b o u t 1 0 % in salt consumption because t h e y can calculate precisely t h e e n d point of t h e softener. A large eastern power p l a n t which has a Q u a n t i c h e m installed t o g u a r d against silica b r e a k t h r o u g h in feedwater m a k e u p has r e duced boiler s t a r t u p from four d a y s t o 24 hours. T h i s has conserved personnel t i m e a n d helped increase p l a n t efficiency. WHAT CHEMICAL ANALYSES ARE AVAILABLE. If you are considering a u t o m a t i c w a t e r analysis—and y o u should be!—remember t h a t only M i l t o n R o y h a s a complete line of e q u i p m e n t . . . T h e inexpensive C H E M A L Y Z E R for accurate, continuous analysis in t h e p p m range of t o t a l hardness, residual chlorine, sulfite, soluble silica, chromâtes, fluoride or p h o s p h a t e s . . . T h e Q U A N T I C H E M w i t h its u n i q u e a u t o m a t i c s t a n d a r d i z a t i o n anel zeroing feature for d e t e r m i n a t i o n s in t h e p p b range of t r a c e substances such as silica, iron, a m m o n i a , copper, h y d r a z i n e a n d t o t a l hardness. Bulletin 1156-2 tells t h e whole story of these t w o money-saving a u t o m a t i c supervisors. Use t h e coupon t o get your copy.
Milton Roy Company 1300 E. Mermaid Lane, Phila. 18, Pa. Send
Bulletin
Company_ Address_ City Circle No. 128 on Readers' Service Card
30 A
·
ANALYTICAL CHEMISTRY
Figure 3. Spectrophotometric termination of methemoglobin
de
A Series: spectra obtained with blood from a patient having methemoglobin emia 3 Series:
blood from normal subject
In both cases, the middle curve was obtained upon blood diluted 1:20, pH 7.3. The upper curves were ob tained after adding a small crystal of potassium ferricyanide, which oxidizes hemoglobin iron to the ferric form. The lower curves were obtained after addition of potassium cyanide, there by converting methemoglobin to cyanmethemoglobin which has no ab sorption band at 630 m^. The fraction of hemoglobin present as methemoglobin is computed from absorbance values at the peak for methemoglobin (628 m^), and is given by the difference between the middle and lower curves, divided by the difference between the upper and lower curves. Correction must be included for the small decrease in absorption that sometimes occurs upon addition of potassium cyanide, (as in the Β series).
certain of the trace metals, some of the steroid hormones.
and
Micro Methods
7756-2
Name Controlled Volume Pumps Colorimetric Analyzers Hydrogen Purifiers Laboratory Instruments
Courtesy of Blood 18, No. 1, p. 21 (1961.) [Grune & Stratton, Inc., Ν. Υ.]
_State_
M a n y micro methods differ little from their macro counterparts, ex cept for being scaled down in size by a factor of 10 to 20. Examples a r e : blood glucose by the Somogyi-Nelson method, serum sodium and
