IMPROVED CHEMICAL ANALYSIS OF EXOGENOUSLY-APPLIED 1,2,4-TRIAZOLES DERIVED FROM APPLE TREE TISSUES AND SOIL RESIDUES

The experimental growth regulator, paclobutrazol or PP333 [(2RS,3RS) -1-(4-chlorophenyl)-4,4-dimethyl-2-(1,2,4-triazol-1-y1)pentan-3-ol)] was extracted from PP333-treated foliage and soil under a revised protocol. In the case of foliar extracts, increasing the amount of sorbent (C₁₈, Florisil) and adding an ultrafiltration step (500 M_W cutoff) afforded greater sample purity, concentration and utilization of HPLC (high performance liquid chromatography) as a final quantification step. PP333 residues obtained from soil low in organic matter required even less purification than plant extracts. In this regard, the Florisil extraction step and ultrafiltration could be omitted and the post-C₁₈ eluant could be directly analyzed for paclobutrazol via HPLC or GC (gas chromatography). Utilization of a semi-preparative HPLC column (9.4 x 250 mm) afforded PP333 sensitivity values that closely approximated those of GC analysis. These results show that less expensive and more rapid analyses of PP333-treated tissue and soil were possible.