Calibration of the HPLC system

Standard mixtures are run on the HPLC system for evaluation of the separation volume, reproducibility and accuracy of the system. The c(Hiqx)sition of the standard mixture depends on the compound class under study. The amounts injected on the HPLC column are from 100 pg (organochlorines) to 1000 ng (hydrocarbons) each in 200pL of solvent (hexane). The solvent volumes required to elute selected groups of organic contaminants are summarized in Table 20-1. The solvent flow rate is 0.5mL/min. The eluates are collected in fractions of 0.5 mL. Each fraction is analysed by GC-ECD or GC-FID (flame ionization detection). Recoveries are from 90 to 100 %. 

To calibrate the system for the separation of chlorobiphenyls from interfering substances the standard mixture should at least contain  

One alkane (n-C2oH42,) hexachlorobenzene (HCB) one trichlorobiphenyl (28) one hexachlorobiphenyl (180) hexachlorocyclohexane (HCH)  

Calibrations with the standard mixture should be repeated after 20-30 sample runs or at least once a week. 

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