A new method for the HPLC determination with the electrochemical detection of plant growth regulator Daminozide, in the presence of 1,1-dimethylhydrazine, its degradation product has been developed. Spectrophotometric detection at 210 nm was not sensitive enough for practical purposes (detection limit about 1 x 10-3 mol L-1 for 1,1-dimethylhydrazine and 1 x 10 -4 mol L-1 for Daminozide). Thus, voltammetric detection on glassy carbon fiber working electrode at +1.4 V vs Ag/AgCl reference electrode has been employed as more sensitive approach (detection limit about 5 x 10-6 tool L-1 for 1,1-dimethylhydrazine and 2 x 10 -6 mol L-1 for Daminozide). Optimum separation on octadecylsilane column (Separon SGX C18) was achieved with Britton-Robinson buffer (pH = 5) as a mobile phase and at the flow rate of 0.3 mL min-1. Under these conditions the retention times of 5.5 min for Daminozide and 9.3 min for 1,1-di-methylhydrazine have been achieved. The same separation conditions and mobile phase were applied to the columns chemically modified with -CN (Separon SGX CN) and -NH2 groups (LiChrosorb-NH20). The following retention times were achieved respectively: 4.4 and 8.6 min for Daminozide, and 7.7 and 3.8 min for 1,1-dimethylhydrazine.
|Состояние||Опубликовано - 27 авг 2003|
|Опубликовано для внешнего пользования||Да|
ASJC Scopus subject areas
- Analytical Chemistry