the accuracy and precision of the measurements should be documented by a 

 series of inter! aboratory and intralaboratory quality control measures. Inter- 

 laboratory calibration exercises utilizing such aids as split or duplicate 

 samples provide consensus verification of analytical accuracy and should be 

 systematically incorporated into every analytical documentation program. Con- 

 sensus verification of analytical accuracy is particularly important in the 

 case of environmental samples because certified standards are not usually 

 available to confirm the absolute accuracy of the data. 



Intralaboratory quality control measures serve primarily as a check on the 

 precision of the analytical data. Intralaboratory control measures should 

 include such procedures as routine instrument calibrations, analysis of sys- 

 tem blanks along with each set of samples, replicate analyses, and preanalysis 

 tests of analytical accuracy, reproducibility, and linearity over the expected 

 concentration range. Of course, the results of all interl aboratory and intra- 

 laboratory quality control measures should be documented for presentation 

 along with the analytical results obtained from the environmental samples. 



Amore (1978) recently proposed the comprehensive quality assessment pro- 

 tocol, incorporating both external (interl aboratory) and internal (intralabor- 

 atory) quality control components, be followed as closely as possible by 

 laboratories doing spill documentation analyses. 



Table 5. Analytical Quality Assessment Protocol 



I. Internal components 



A. Blind duplicate 



B. Spiked blanks 



C. Spiked samples 



D. Certified standards 



E. Instrument control chart 



F. Synthetic samples 



G. Secondary standard samples 



II. External components 



A. Proficiency samples 



B. Round robins 



C. Blind duplicates 



195 



