Unprecedented Computer Power for the Lab
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Report for Analytical Chemists Unprecedented Computer Power for the Lab Harness the full power uf interactive time-sharing cura- |)ii!i:rs to simplify (hitil record- ing unci speed data analysis with our Model 131 Instru- ment / Computer Interface System. This new Γ.Λ.Κ. sys- tem links your laboratory in- struments directly to a remote computer over ordinary phono lines. While your experiment is running, instrument output data is simultaneously fed to the computer where it is reduced, correlated or inter- preted. Just seconds later, results are back in your lab! Yuu ran use the Model 131 to process analog or digital data from 1 to ds many as tlu similar or différent instru- ments. It also provides an added capability for using the computer to monitor and control experiments, tests and open-loup processes. And I he analytical capabilities of cer- ium lahoi-alory instruments can even be extended through the Model 1.11. The modularized Model 131 System is easily expanded as your instrumentation and data processing requirements «row. Price of a typical sys- tem is less than S4.500. Tele- printer and acoustic coupler available at nominal extra cost. Complete details are available in P.A.R. Bulletin T-200A. For a copy, write Princeton Applied Research Corporation. Box 565, Prince- Ion. New Jersey 08540, or call (009) 924-6835." CIRCLE 1 4 7 O N READER SERVICE CARD dicularly to the optical beam and at the point where the image of the slit is formed. Under these condi- tions, the vertical image is about 13 mm x 2 mm and is located in the center of the opening in the metal holder. The filter holder and the size and shape of the filters were selected to conform to the dimensions of the sample compartment of most con- ventional spectrophotometers. The filters are approximately 1.0, 1.5, and 2.0 mm thick. Corresponding to these thicknesses are nominal transmittances of 30, 20, and 10%, respectively. These thicknesses were selected to provide a means for calibrating the photometric scale at three different levels. A point of philosophy should be brought up at this time in connec- tion with the spectrophotometry standardization. The set of neutral glass filters has been top priority in our program because of the urgent requests of the Standards Commit- tees. However, it appears that these glasses will be used by re- search laboratories and by clinical analytical laboratories who need to standardize rather elaborate spec- trophotometers. A glass filter will be less suitable to standardize the thousands of automated systems which rely on continuously circu- lating discrete volumes of solutions through plastic tubes and finally through small colorimeter cells. Thus, as we see it now, the primary effort of our spectrophotometry pro- gram will be oriented toward pro- viding the standardization means necessary for these automated sys- tems. This is a major problem and will be a difficult one to solve. Our present schedule calls for the first liquid spectrophotometry standards to be available by July of this year. These will be composite solutions available in disposable ampuls and containing either (a) chromium (III), cobalt (II), and p-nitrophenol, or (b) Thomson solution (14)—a mixture of chro- mium (III), chromium (VI), co- balt (II), and copper (II). A num- ber of these samples are being eval- uated by clinical laboratories. The results of these cooperative tests, together with accurate measure- ments obtained on our high-ac- curacy instrument will be combined with our studies of stability and storage characteristics to provide the certification for these NBS liquid spectrophotometry SRMs. Spectrofluorometry Much of the current work pre- sented . at scientific meetings and in publications points out the grow- ing usefulness of fluorescence mea- surements in the biochemical and environmental fields. These mea- surements complement the present capabilities of spectrophotometry by permitting measurements at lower concentrations, smaller sam- ple sizes, and with greater spe- cificity. However, conventional spectronuorometric instruments are not capable of making absolute measurements, and standards are therefore urgently needed to pro- vide a means of calibration. Within the last year, Division scientists have begun studying some of the problems associated with fluorescence measurements. Pre- liminary work has led to the selec- tion of several materials as poten- tial quantum efficiency standards. It is proposed that cerium, lead, and thallium glass filters, and solutions, such as quinine sulfate, 3-amino- phthalimide, the aluminum chelate of Pontochrome Blue Black R, and m-nitrodimethylaniline, be eval- uated. The measurement of quan- tum yields of these compounds will depend on the development and con- struction of a high-accuracy spec- trofluorometer which will be cali- brated at NBS by independent physical means in a similar manner to the high-accuracy spectropho- tometer. pH and Ion-Selective Electrodes pH. It has long been recognized that the pH of blood reflects the acid-base balance of the body. The pH level is controlled between rela- tively narrow limits by intricate mechanisms involving the produc- tion, elimination, and buffering of acid by the body. Its measurement is of great significance and may be related to a large number of spe- cific pathologic states including respiratory, gastrointestinal, and renal diseases. In the clinical laboratory, pH is one of the most commonly per- formed determinations using an 42 A • ANALYTICAL CHEMISTRY, VOL. 43, NO. 6, MAY 1971
Transcript of Unprecedented Computer Power for the Lab
Report for Analytical Chemists
Unprecedented Computer Power
for the Lab Harness the full power uf interactive time-sharing cura-|)ii!i:rs to simplify (hitil recording unci speed data analysis with our Model 131 Instrument / Computer Interface System. This new Γ.Λ.Κ. system links your laboratory instruments directly to a remote computer over ordinary phono lines. While your experiment is running, instrument output data is simultaneously fed to the computer where it is reduced, correlated or interpreted. Just seconds later, results are back in your lab! Yuu ran use the Model 131 to process analog or digital data from 1 to ds many as tlu similar or différent instruments. It also provides an added capability for using the computer to monitor and control experiments, tests and open-loup processes. And I he analytical capabilities of cerium lahoi-alory instruments can even be extended through the Model 1.11. The modularized Model 131 System is easily expanded as your instrumentation and data processing requirements «row. Price of a typical system is less than S4.500. Teleprinter and acoustic coupler available at nominal extra cost. Complete details are available in P.A.R. Bulletin T-200A. For a copy, write Princeton Applied Research Corporation. Box 565, Prince-Ion. New Jersey 08540, or call (009) 924-6835."
CIRCLE 147 O N READER SERVICE CARD
dicularly to the optical beam and at the point where the image of the slit is formed. Under these conditions, the vertical image is about 13 mm x 2 mm and is located in the center of the opening in the metal holder.
The filter holder and the size and shape of the filters were selected to conform to the dimensions of the sample compartment of most conventional spectrophotometers. The filters are approximately 1.0, 1.5, and 2.0 mm thick. Corresponding to these thicknesses are nominal transmittances of 30, 20, and 10%, respectively. These thicknesses were selected to provide a means for calibrating the photometric scale at three different levels.
A point of philosophy should be brought up at this time in connection with the spectrophotometry standardization. The set of neutral glass filters has been top priority in our program because of the urgent requests of the Standards Committees. However, it appears tha t these glasses will be used by research laboratories and by clinical analytical laboratories who need to standardize rather elaborate spectrophotometers. A glass filter will be less suitable to standardize the thousands of automated systems which rely on continuously circulating discrete volumes of solutions through plastic tubes and finally through small colorimeter cells. Thus, as we see it now, the primary effort of our spectrophotometry program will be oriented toward providing the standardization means necessary for these automated systems. This is a major problem and will be a difficult one to solve.
Our present schedule calls for the first liquid spectrophotometry standards to be available by July of this year. These will be composite solutions available in disposable ampuls and containing either (a) chromium ( I I I ) , cobalt ( I I ) , and p-nitrophenol, or (b) Thomson solution (14)—a mixture of chromium ( I I I ) , chromium (VI) , cobalt ( I I ) , and copper ( I I ) . A number of these samples are being evaluated by clinical laboratories. The results of these cooperative tests, together with accurate measurements obtained on our high-accuracy instrument will be combined
with our studies of stability and storage characteristics to provide the certification for these NBS liquid spectrophotometry SRMs.
Spectrofluorometry
Much of the current work presented . a t scientific meetings and in publications points out the growing usefulness of fluorescence measurements in the biochemical and environmental fields. These measurements complement the present capabilities of spectrophotometry by permitting measurements a t lower concentrations, smaller sample sizes, and with greater specificity. However, conventional spectronuorometric instruments are not capable of making absolute measurements, and standards are therefore urgently needed to provide a means of calibration.
Within the last year, Division scientists have begun studying some of the problems associated with fluorescence measurements. Preliminary work has led to the selection of several materials as potential quantum efficiency standards. I t is proposed that cerium, lead, and thall ium glass filters, and solutions, such as quinine sulfate, 3-amino-phthalimide, the aluminum chelate of Pontochrome Blue Black R, and m-nitrodimethylaniline, be evaluated. The measurement of quantum yields of these compounds will depend on the development and construction of a high-accuracy spec-trofluorometer which will be calibrated at NBS by independent physical means in a similar manner to the high-accuracy spectrophotometer.
pH and Ion-Selective Electrodes p H . I t has long been recognized
tha t the pH of blood reflects the acid-base balance of the body. The pH level is controlled between relatively narrow limits by intricate mechanisms involving the production, elimination, and buffering of acid by the body. I ts measurement is of great significance and may be related to a large number of specific pathologic states including respiratory, gastrointestinal, and renal diseases.
In the clinical laboratory, pH is one of the most commonly performed determinations using an
42 A • ANALYTICAL CHEMISTRY, VOL. 43, NO. 6, MAY 1971
