六种手性三唑类杀菌剂对映体的超临界流体色谱法分离

采用超临界流体色谱,以超临界二氧化碳(CO2)作为流动相,研究了6种手性三唑类杀菌剂(苄氯三唑醇、联苯三唑醇、叶菌唑、乙环唑、糠菌唑和醚唑)在Chiralcel OD-H手性色谱柱上的对映体分离。考察了不同改性剂种类(甲醇、乙醇、异丙醇)、体积分数(0~15%)以及系统背压(13~17 MPa)对分离效果的影响,并与其在Sino-Chiral OJ和Chiralpak IB手性色谱柱上的分离效果进行了比较。结果表明:单独以超临界CO2为流动相时,6种三唑类杀菌剂的保留时间均大于60 min,而添加了醇类改性剂后其在40 min内均得到了洗脱。苄氯三唑醇、联苯三唑醇、叶菌唑和糠菌唑在柱温为34℃、系统背压为15 MPa、流动相流速为2 m L/min时,在20 min内均实现了基线分离(Rs≥1.5);优化改性剂(体积分数)分别为3%乙醇、13%乙醇、6%甲醇和7%乙醇。Chiralcel OD-H柱对6种供试杀菌剂的手性识别效果优于Sino-Chiral OJ和Chiralpak IB柱,但对映体分离时间要长10~20 min。

Chiral separation of six triazole fungicides by supercritical fluid chromatography

The enantiomeric separation of six triazole fungicides (diclobutrazol, bitertanol, metconazole, etaconazole, bromuconazole and difenoconazole) on the Chiralcel OD-H column by supercritical fluid chromatography, using supercritical carbon dioxide as the mobile phase, was investigated. The influences of pressure (13-17 MPa), modifiers (methanol, ethanol and 2-propanol) and their contents in the mobile phase (0-15%,V/V) on the separation of enantiomers were evaluated. The results were compared with those obtained on Sino-Chiral OJ and Chiralpak IB column. The results showed that the retention times of six triazole fungicides were longer than 60 min under pure CO2 and it could be reduced to less than 40 min when adding organic modifiers. The enantioseparations of diclobutrazol, bitertanol, metconazole and bromuconazole were achieved within 20 min at 34 ℃, 15 MPa at a flow-rate of 2 mL/min. Their optimal concentrations of modifiers were 3% (V/V) ethanol, 13% (V/V) ethanol, 6% (V/V) methanol and 7% (V/V) ethanol. The Chiralcel OD-H column demonstrated a better enantiomeric separation capacity and a 10-20 min's longer retention time for the triazole fungicides.