Jc. Deandrade et al., TIME-BASED INJECTION APPROACH FOR MONOSEGMENTED CONTINUOUS-FLOW SYSTEMS AND RELATED TECHNIQUES, Journal of automatic chemistry, 18(6), 1996, pp. 199-203
A time-based injection module for monosegmented continuous flow system
s and related techniques, which uses three independently controlled so
lenoid valves, is described. A timer circuit employing three I.C. 555s
and three TIP-121 transistors was constructed to control the injectio
n module valves. The injection device was tested with non-reacting che
mical systems (for example with a spectrophotometric standard and calc
ium flame emission) and with reacting conditions (for example the dete
rmination of Cr(VI), using diphenylcarbazide as colour reagent, and ac
id-base titration). The performance of this injection module demonstra
tes its suitability for everyday use.