Analytical acceptibility

Accuracy (systematic error or bias) expresses the closeness of the measured value to the true or actual value. Accuracy is usually expressed as the percentage recovery of added analyte. Acceptable average analyte recovery for determinative procedures is 80-110% for a tolerance of > 100 p-g kg and 60-110% is acceptable for a tolerance of < 100 p-g kg Correction factors are not allowed. Methods utilizing internal standards may have lower analyte absolute recovery values. Internal standard suitability needs to be verified by showing that the extraction efficiencies and response factors of the internal standard are similar to those of the analyte over the entire concentration range. The analyst should be aware that in residue analysis the recovery of the fortified marker residue from the control matrix might not be similar to the recovery from an incurred marker residue. 

A closer look at the prediction of the concentration for a single sample absorbance of 0.500 is shown in Figure 30. The least squares best fit value for the analyte concentration is 0.0868%. There is a 95% probability that the true concentration will lie +0.0115% of the estimated value. The question is whether a 13% relative spread at 0.0868% is analytically acceptable. If this is not so, then the calibration procedure has to be reinvestigated to reduce variability. 

Product Quality. Work was undertaken to show that the Ceftibuten product produced via the electrochemical route was analytically acceptable (indeed at least as pure) as that produced by the Shionogi process. 

Assisting in the evaluation and interpretation of results to ensure that the data are analytically acceptable and correctly correlated to tell the story of the experimental results. 

Documentation and the same type of procedures are important for mixtures of articles with carriers. In addition, procedures for each test or control article that is mixed with a carrier, appropriate analytical methods shall be conducted to determine the uniformity and stability of the mixture and the concentration of the test or control article in the mixture. In GLP studies, these assays should incorporate validated methods. SOPs need to define general ranges for standard parameters used for analytical acceptability. 

Table III. Results of Analytical Acceptability Checks in Selected Mine Drainages (first nine samples) and Stream Water (SW) Samples...

Once these analytes have moved ahead of the film boundary they are no longer retarded and are lost through the solvent vapor exit. The loss of partially trapped analytes is more critical in on-line SPE-GC than for conventional large volume injection because of the nonuniform distribution of analytes in the solvent film. The introduction of a small volume of organic solvent, presolvent, immediately in front of the sample plug to ensure that a solvent film is already present in the retention gap when sample transfer starts, can be used to minimize the loss of volatile analytes. Acceptable recovery of analytes as volatile as xylene and chlorobenzene was obtained using an on-column interface when 30-50 jl1 of methyl acetate was introduced immediately in front of 50 xl of the same desorption solvent. 

Fig. 12.39. ESI features a wide range of analyte acceptance in terms of both poiarity and mass to handle medium polar to ionic analytes while APCI and APPI give access to the lower left segment of the polarity-mass plane. Adapted with permission of U. Karst from cover illustration of Anal. Bioanal. Chem. 378(4), 2004. Springer, Heidelberg, 2004.

JUDGING THE PASSIVE RESTRAINTS RULE BASED ON THE FIVE CRITERIA FOR ANALYTICAL ACCEPTABILITY... 

Salient features of this new, innovative, occupant protection standard and its justification deserve comment. The five criteria recommended for judging analytical acceptability, which were presented as questions in the last section of this essay, are helpful... 

Just as imperfections can be found in the traffic safety behavior of individual travelers so can imperfections be found in the formulation and implementation of traffic safety policy. Vehicle technology has been emphasized at the expense of nontechnological safety measures. Safety of passenger car occupants has been emphasized at the expense of other travelers. Net benefits of crashworthiness standards such as mandatory passive restraints have been exaggerated because safety gains are overestimated and some costs are ignored. The Dole Rule on passive restraints only partly satisfies the five criteria for analytical acceptability. 

A general policy framework such as the individual cost benefit approach suggests improvements which can be made in evaluation of traffic safety policy. For ex ante evaluation of an single standard five criteria were developed in Chapter 4 forjudging analytical acceptability. The criteria cover ... 

Five criteria for jud g the analytical acceptability of ex ante evaluation of a proposed safety standard for administrative and legal dedsions ... 

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