Report for Analytical Chemists
BUCHLER UNIVERSAL DENSITY GRADIENT MIXER FORMS GRADIENTS FROM 5 to 50 ml WITHIN THE SAME MIXER
A GRADIENT SEDIMENTATION SYSTEM FOR THOSE WHO MUST VARY VOLUME FREQUENTLY! • Prepare 5, 30 or 50 ml gradients with a single unit. · Chambers available for single or triple gradient mixing. · Piercing unit—with adapters to hold all commercially available centrifuge tubes. · Precision bore conical chambers with interconnecting stopcock. · Vibration type stirrer with adjustable speed. · Pumps, UV monitors and fraction collectors to form complete system. Write for Bulletin AC2-5100
visory Panel regarding t h e N B S standardization of bilirubin (16) will p u t the N B S contribution into perspective: " T h e program in clinical standards illustrates dramatically t h e unique role and capability of the Bureau in providing materials standards. T h e Analytical Division has been involved for just over a year in clinical chemical s t a n d a r d s ; several new S R M s are now offered, with another soon to be offered— bilirubin. Bilirubin standardization has been an extremely recalcit r a n t problem which has been a t tacked over the last decade by cooperative groups of scientists, both here and abroad, with incomplete success. " I n one year the Bureau has achieved a bilirubin S R M (solid) plus a tested new method of preparing a stable concentrated standard solution which can be added to serum or plasma without denaturing protein. T h e Division has thus unmistakably demonstrated t h a t (1) the Bureau's competence is qualitatively superior to t h a t in the field, (2) the Bureau acts as a stimulus to industry—there are now three bilirubin suppliers, (3) the Bureau can provide an unbiased unifying authority in the clinical field (which is very sensitive to authority) , (4) the Bureau can provide not only an S R M , but can also provide a method of use t h a t makes practical both t h e S R M and industrial secondary standards." One thing is certain, with the pressures on t h e clinical laboratory to be able to prove its capability, there will be a great demand for standard reference materials. Traceability to the National Bureau of Standards will ensure consistent quality control between individual laboratories. Ultimately this will lead to upgrading of t h e measurements made in the clinical laboratory. Acknowledgment
BUCHLER INSTRUMENTS
BUCHLER INSTRUMENTS DIVISION NUCLEAR-CHICAGO CORPORATION A S U B S I D I A R Y O F G . D . | S E A R L E | S, C O . 1327 S I X T E E N T H ST.. FORT L E E , N.J. 07024
T h e clinical S R M program is D i vision-wide in scope. Names of several major contributors have been mentioned in the text but over half of the 100 scientists in our N B S Analytical Chemistry Division have been involved in this program at one time or another during the past
CIRCLE 1 7 O N READER SERVICE CARD
46 A • ANALYTICAL CHEMISTRY, VOL. 43, NO. 6, MAY 1971
five years. This report and t h e series of S R M s in clinical chemistry are indeed a tribute to the harmonious interaction of these diverse scientific efforts within our Division. References (1) "Analytical Chemistry: Key to Progress in National Problem Areas," announcement of 24th Annual Summer Symposium on Analytical Chemistry to be held June 16-18, 1971, a t the National Bureau of Standards, Gaithersburg, Md. (2) L. L. Abell, B. B. Levy, B. B. Brodie, and F . E. Kendall, J. Biol. Chem., 195,357 (1952). (3) L. F . Fieser, / . Amer. Chem. Soc, 75,5421 (1953). (4) "Selection of Criteria for a Pure Cholesterol Preparation to Be Used for Standardizing Serum Cholesterol Measurements for Medical Diagnosis and Therapy," Amer. J. Clin. Pathol., 47, 654 (1967). (5) R. Schaffer, A. Cohen, R. F . Brady, Jr., "Cholesterol: Standard Reference Material 911," ibid., submitted for publication. (6) B. Coxon, R. Schaffer, "Characterization and Quantitative Analysis of DGlucose for Use in Clinical Analysis," ANAL. CHEM., submitted for publica-
tion. (7) J. Fog, Scand. J. Clin. Lab. Invest., 16,49 (1964). (8) Z. J. Petryka, C. J. Watson, J. Chromatog., 37, 76 (1968). (9) R. Schaffer, R. F. Brady, Jr., A. J. Fatiadi, B. A. Johnson, B. F. West, "A Crystalline Bilirubin Standard for Clinical Analysis, SRM 916," Science, submitted for publication. (10) R. A. Velapoldi, O. Menis, "Bilirubin Stability—Spectral Shifts of Transition and Rare Earth Element Complexes," Clin. Chem., submitted for publication. (11) A. J. Fatiadi, R. Schaffer, "Periodic Acid as a New Oxidant for the Degradation of Bile Pigments. Isolation of a Biliverdine Type of Reaction Intermediate on Oxidation of Bilirubin with Periodic Acid," Experientia, submitted for publication. (12) R. Mavrodineanu, "Solid Materials to Check the Photometric Scale of Spectrophotometers," NBS Technical Note 544, Menis, O., Shultz, J. I., Ed., pp. 6-17, U. S. Government Printing Office, Washington, D. C. 20402 (September 1970). (13) K. S. Gibson, "Spectrophotometry," NBS Circ. 484 (September 1949). (14) L. C. Thomson, Trans. Faraday Soc, 42, 663 (1946). (15) T. Peters, Jr., Clin. Chem., 14, 1147 (1968). (16) NBS Analytical Chemistry Division Advisory Panel Report, January 1970. Certain commercial materials and instruments are identified in this paper in order to specify the experimental procedure adequately. In no case does such identification imply recommendation or endorsement by the National Bureau of Standards, nor does it imply that the material or equipment identified is necessarily the best available for the purpose.
