REPORT FOR A N A L Y T I C A L CHEMISTS
ditions t h e y used (5) ; a relatively narrow absorbance range is there fore required in t h e most precise work. T h e y also showed t h a t m e a surement precision did not increase when t h e y used high-brightness hol low-cathode t u b e s although t h e sen sitivity was higher. T h e r e is general agreement now in A S T M work on AAS methods
0
20
40
t h a t a method should include infor m a t i o n on the sensitivity (slope) t o be expected at both t h e u p p e r and lower working limit of t h e calibra tion curve, and t h e m i n i m u m slope acceptable a t both points. A straight line relationship is n o t as sumed. I t is also generally agreed t h a t the method should include a s t a t e m e n t about t h e precision of
60
80
100
if you're
CREATIVE
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Concentration, mg/l (Courtesy Perkin-Elmer
Corp.)
Figure 7. Absorbance curves for nickel with normal and high-brightness lamps (6) 2.0
SEND ME the following illustrated MP-System laboratory manuals: Π MPI Applications Notes Vol. 1 $1 Π MPI Applications Notes Vol. 2 $1 Π MPI Operation and Applications Manual $2 Π New Laboratory Textbook by Dr. L. P. Morgenthaler $3.50 Name Street_State_
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0.5 Absorbance (Courtesy Perkin-Elmer
McKEECorp.)
Figure 8. Coefficients of variations determined with recommended operating conditions (9)
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INSTRUMENTS
BOX 322, DANVILLE, CA 94526 Circle No. 71 on Readers' Service Card
VOL 40, NO. 12, OCTOBER 1968
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