Washington conference

R. A. Potter, "Neat Methanol Fuel Injection Fleet Alternative Fuels Study," paper presented at Eourth Washington Conference on Alcohol, Washiagton, D.C.,Nov. 1984. 

T. N. Irvine, ed.. Chromium Its Physicochemical Behavior and Petrologic Significance, Carnegie Institution of Washington Conference, Geophysical Laboratory, Pergamon Press, Inc., Elmsford, N.Y., 1977. 

In 1938 Bethe formulated the mechanism for energy generation in stars. This research grew out of his participation at the third Washington conference on theoretical physics in April 1938. The reaction... 

Hartmann, C., Massart, D. L., McDowell, R. D. An analysis of the Washington Conference Report on bioanalytical method validation. J. Pharm. Biomed. Anal., 12, 1994, 1337... 

Erik Goldstein and John Maurer (eds.) The Washington Conference, 1921—22 Naval Rivalry, East Asian Stability and the Road to Pearl Harbor (Ilford Frank Cass, 1994). 

During the 1990 Washington Conference on Analytical Methods Validation Bioavailability, Bioequivalence and Pharmacokinetic Studies [1], parameters that should be used for method validation were defined. The final report of this conference is considered the most comprehensive document on the validation of bioanalytical methods. Many multinational pharmaceutical companies and contract research organizations contributed to its final draft. This scientific meeting was sponsored by the American Association of Pharmaceutical Scientists (AAPS), the Association of Official Analytical Chemists (AOAC), and the U.S. Food and Drug Administration (FDA). The conference report has been used as a reference by bioanalytical laboratories and regulatory agencies worldwide. 

The glossaries in the 1990 and 2000 Washington conference final reports [1,3] define most of the analytical terms used in the validation of a method. However, internationally accepted definitions such as those by ISO or IUPAC already exist and have been elaborated carefully over many years [2,6]. The definitions reported in the 1990 and 2000 Washington conference final reports sometime agree only partially with the ISO and IUPAC. Following are some examples for comparison. 

Selectivity is the ability of the bioanalytical method to measure and differentiate the analytes in the presence of components that may be expected to be present. Specificity is the ability to assess unequivocally the analyte in the presence of components that may be expected to be present. In general, analytical methods are selective, and only in same cases also specific (e.g., an LC-MS/MS bioanalytical method is highly selective but not always also specific because it could be possible to find in the complex biological matrix an interference with the same retention time, molecular weight, and main fragment of the analyte of interest). Even if the 2000 Washington conference focuses only on selectivity, it is up to bioanalytical laboratories to differentiate in their documentation between selectivity and specificity or consider them equivalent and use them interchangeably. 

The 2000 Washington conference guidelines suggest analyzing at least six independent sources (i.e., six different lots or six different individual samples) of blank plasma or urine separately, and demonstrate that no substances are present that interfere with the quantification of the analyte. The degree of compliance with this guideline changes from lab to lab as the number of independent sources tested. 

Limited Quantity of Matrices. For biological matrices that are difficult to obtain, only a single source may be available and is therefore the only possibility for testing selectivity. These matrices include, but are not limited to, human and primate tissue and cerebrospinal fluid. In the absence of the corrected biological matrix, as the 2000 Washington conference final report suggests, a physiologically appropriate proxy matrix can be used. 

The 2000 Washington conference final report stated clearly (see Section 8.2.4) that selection of weighing should be justified. In general, it is possible to justify the weighing used considering that the data produced by bioanalytical methods do... 

The amount of internal standard added should be similar to the amount of analyte contained in the sample. In fact, errors are minimized when the relative responses for analyte and internal standard are comparable. If a wide concentration range is to be measured, the amount of internal standard should be selected to maximize precision where it is critically important. As a general rule, with a six-level calibration curve, the internal standard concentration, should be between the second and third calibration standard concentration depending on the relative instrument response for analyte and internal standard and precision at the LLOQ level (i.e., internal standard should be closer to LLOQ if the precision of the LLOQ is low). Many bioanalytical laboratories use a written policy for rejecting sample with low internal standard even though it is not suggested by the 2000 Washington conference final report. 

Recovery. In the 2000 Washington Conference final report it is clearly stated that knowledge of recovery is not essential to assay validation, but it does provide useful information about the real amount of analyte that is being analyzed. Assessment of recovery at every step of sample preparation and analysis in which losses may occur provides a powerful diagnostic tool to improve the method if needed. If a good internal standard has been chosen, the losses will have no impact on quantitation because they will be similar for analyte and internal standard and will thus annul each other. On the other hand, recovery is very important to verify if the internal standard really mimics and matches the analyte. The discovery of significant and inconsistent differences in recovery between analyte and internal standard at different steps of sample cleanup and analysis could indicate possible failure of the method during the validation. 

The 1990 and 2000 Washington conference final reports and FDA guidance for the industry state that partial validation is required with a change in species within... 

The second day was given over to free-ranging discussions concerning the points raised on the first day. In summary, the Washington Conference identified as preservation needs of greatest priority the concept of a national preservation collection, the continuing need for scientific research, the training of conservators, and the education of library administrators. 

Zumberge, J. E. Hie effect of D-glucose on aspartic acid racemization. Paper presented at the Carnegie Institution of Washington Conference Advances in the Biogeochemistry of Amino Acids, Warren ton, Virginia, Oct. 29-Nov. 1, 1978. 

There was then, after WWI, a preponderance of opinion in favour of the view that CW was a particularly unpleasant form of warfare and that those who supported it, with the exception of industrialists perceived to be concerned with preserving national security, were either cranks or simply deluded. These general feelings were reflected by the attempt by the USA to place some limits on the development of a variety of weapon systems by calling the Washington Conference on the Limitation of Armaments in 1921-1922. CW was referred to a subcommittee which considered the development of this form of warfare during WWI and concluded that it was impracticable to attempt to limit the use of chemicals any more than that of explosives, and stated, regarding chemical weapons ... 

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