http://mercuryanalyser.com/mercury-testing/mercury-analysis-in-water-cleaning-your-containers/ When measuring mercury at sub pg/g level, there is a strict quality control procedure you need to comply.<br /><br /> You need to prepare at least 5 calibration standards, with the lowest standard being 0.5 pg/g or 1 pg/g depending on you are in America or Europe.<br /> The linearity of the calibration curve needs to be in a accepted range<br /> The intercept of the calibration curve needs to be less than half of the slope<br /> The recovery of the lowest standard need to be within certain range<br /> An ‘on going standard’ needs to be used for controlling the drift<br /> An ‘independent standard’ needs to be prepared by another person or from independent source to ensure the accuracy of the calibration standards<br /> The usage of reference material is highly recommended<br /> Random sample needs to be spiked in duplicate, the spike recoveries of these two<br /> sample need to be within certain range
