Automated multielement analysis over extended periods of time

Automated multielement analysis over extended periods of time 

Long-time monitoring imposes different constraints to short-term measurements. For example, different columns listed below display different performance characteristics with respect to long-term use. 

Silica based Cig reversed-phase chromatographic columns were used as follows (i) A Cig /xBondapak column from Waters Associates, length = 30 cm, internal diameter (i.d.) = 3.9 mm, particle size = 10 fim (ii) A Ci8 Spherisorb column from Altex, length = 25 cm, i.d. = 4.6 mm, particle size = 5 m (iii) A Cig Radpak column used in conjunction with a Radial compression module (RCM-100) from Waters Associates, length = 10 cm, i.d. = 8 mm, particle size = 10 fim. 

Column iii, the Cig Radpak column, gave lower background levels but was found unsuitable for long-term use, because the column 

Examination of a range of industrial effluents was considered over an extended time period (72 hours), using electrochemical detection (for Ni and Cu) and spectrophotometric detection (for Ni, Cu, Cd, Pb, Co and Hg). With three sample injections per hour, followed by one standard solution injection, results were reproducible ( 3%) over a period of 

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