柱前衍生反相高效液相色谱法同时测定植物络合素（PC_n）等巯基化合物

介绍一种荧光试剂monobromobimane柱前衍生，反相高效液相色谱-荧光检测测定标准样品和植物组织中植物络合素（PCn）等巯基化合物的方法。结果表明，采用乙腈和0.1%三氟乙酸组成的二元梯度洗脱程序，标准混合液中PCn等5种巯基化合物15min内得到很好的分离。以谷胱甘肽为代表考察方法的精密度，在1.25～160ng/μL浓度范围内与峰高有较好的线性关系，相关系数r2=0.9999。谷胱甘肽的回收率平均为97.64%，40d内的变异系数平均为2.21%。方法具有快速、灵敏、稳定性好、易于实施、同时测定PCn等多种巯基化合物等优点。通过该方法的应用，首次揭示Cd超积累植物东南景天对Cd的超量积累和解毒与PCn无关。

In this paper phytochelatins (PC_n) and other thiol-containing compounds in the mixed standard solution and plant tissues were analyzed by RP-HPLC separation and fluorescence detection with monobromobimane pre-column derivatization. The results showed that by using ACN-0.1 % TFA binary gradient elution, PC_n and other thiol-containing compounds in the mixed standard solutions were rapidly separated within 15 min. Glutathione was representatively selected to test the precision of this method. The calibration curve was linear in a wide range of 1.25～160 ng/μL （regression coefficient r~2=0.999 9）. It was confirmed that this method was rapid, simple, highly sensitive, stable, and had a property of the simultaneous determination of PC_n and other thiol-containing compounds. This method has been applied to determine PC_n and other thiol-containing compounds in a Cd hyperaccumulator Sedum alfredii in response to Cd. It was found that Cd hyperaccumulation and detoxification in this plant is not based on PC_n synthesis, since no PC_n was detected in any tissue at any Cd treatment.