Procedure involves dissolution of samples to prepare them for analysis, and uses single set of experimental conditions to analyze wide variety of materials and compositions without compromising analysis accuracy. Automated spectrometer alloys per sample analysis time of four minutes after sample dissolution

Gordon, W. A.

English

NASA Technical Reports Server

September 1971	 Brief 71-10359 
NASA TECH BRIEF 
Lewis Research Center
	
-0 
NASA Tech Briefs announce new technology derived from the U.S. space program. They are issued to encourage 
commercial application. Tech Briefs are available on a subscription basis from the National Technical Information 
Service, Springfield; Virginia 22151. Requests for individual copies or questions relating to the Tech Brief program may 
be directed to the Technology Utilization Office, NASA, Code KT, Washington, D.C. 20546. 
Simplified Procedure for Emission Spectrochemical Analysis 
. 
Alftk
A simplified single procedure for rapid quantitative 
spectrochemical analysis can handle virtually any 
metallic sample, regardless of size or composition. 
Emission spectroscopy, a well established technique 
in chemical analysis, is especially suited to high volume 
routine analyses of a single sample type; i.e., samples 
of the same physical form and of relatively narrow 
composition ranges. The technique becomes pro-
gressively more limited in applications with samples 
of varying sizes, compositions, and physical structures, 
and ultimately becomes impractical for the quantita-
tive analysis of few-of-a-kind samples. The major 
limitation in the spectrochemical analysis of non-
routine samples is the necessity to develop detailed 
procedures, such as sample preparation, spectra 
excitation, quantitative calibrations, and data re-
duction, for each different sample type. The time 
and cost required to quantify the procedures ef-
fectively cancels the potential advantages of the 
spectrochemical technique for analyzing only a few 
samples. 
In the new technique, a relatively simple procedure 
involving dissolution of samples is used to prepare 
all samples for analysis, and all samples are analyzed 
using a single set of experimental conditions. 
In many cases, no comparison standards are necessary 
because the procedure effectively reduces so-called 
matrix effects. (When standards are necessary, they 
can be easily prepared by blending stock solutions 
of the various metal constituents.) This single pro-
cedure can be used to analyze a wide variety of 
materials and compositions, without compromising 
analysis accuracy and without requiring numerous 
separate and more complex procedures. 
Because the identical procedural steps are used 
for all dissolved samples, the procedure has been
automated to achieve a high sample rate. With the 
use of this automated spectrometer, the per sample 
analysis time is about four minutes after sample 
dissolution. Normally, triplicate excitations are made 
of each sample solution. The system will perform 
automatic excitations of a series of samples and will 
record the analysis data from a maximum of 22 metal 
constituents. Computer data processing is used to 
compute either absolute microgram amounts of 
metals or percentage compositions. The computer 
program also provides automatic correction of spectral 
line interferences. 
The instrument system and procedures have been 
successfully applied to the quantitative analysis of 
a wide variety of sample type, including high tem-
perature and refractory alloys, extracted phases from 
these alloys, oxide vapor deposits on platinum and 
glass substrates, 10-microgram microspheres of 
condensed metal aerosols, metal constituents con-
centrated at fracture surfaces of alloys, industrial 
hygiene and pollution samples, and trace metals in 
biological samples. 
This development was made possible by several 
key refinements in the use of a direct current arc 
which is used to excite the atomic spectra. The 
elimination of arc wander and the control of light 
intensity or arc current, together with the operation 
of the arc under closely controlled conditions in 
argon atmospheres, resulted in the required detec-
tion limits and precision for the successful application 
of this procedure. 
Notes: 
I. Control of the arc current light intensity is de-
scribed in NASA Tech Brief 67-10404, Control 
Apparatus for Spectral Energy Source, which may 
tenitiriued III erleaf) 
This documett was prepared under the sponsorship of the National 
Aeronautics and Space Administration. Neither the United States 
Government nor any person acting on behalf of the United States
Government assumes any liability resulting from the use of the 
information contained in this document, or warrants that such use 
will be free from privately ownedrights.
https://ntrs.nasa.gov/search.jsp?R=19710000357 2020-03-17T02:29:36+00:00Z
be obtained from the Technology Utilization 
Division, NASA, Code KT, Washington, D. C. 
20546. 
2. The following documentation may be obtained 
from: 
National Technical Information Service 
Springfield, Virginia 22151 
Single document price $3.00 
(or microfiche $0.95) 
Reference: 
NASA-TN-D-5532 (N70-10367), Quantitative 
Direct Current Arc Analysis of Random Com-
positions of Microgram Residues in Silver 
Chloride Common-Matrix
3. Technical questions may be directed to: 
Technology Utilization Officer 
Lewis Research Center 
21000 Brookpark Road 
Cleveland, Ohio 44135 
Reference: B71-10359 
Patent status: 
No patent action is contemplated by NASA. 
Source: W. A. Gordon

Lewis Research Center

(LEW- 10985)
. 
. 
Brief 71-10359 Category 04


Simplified procedure for emission spectrochemical analysis

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