将MS培养基样品捣碎、混匀,分取10 g,加入乙腈10 mL,振荡20 min。加入氯化钠1.14 g、无水硫酸钠2.24 g,振荡20 min,离心5 min。上清液过0.22 μm滤膜,滤液进入高效液相色谱仪,在InertSustain C₁₈色谱柱(150 mm×4.6 mm,5 μm)上以不同体积比的乙腈和磷酸盐缓冲溶液(pH 3.5)的混合液进行梯度洗脱分离,并在二极管阵列检测器中以272,221,223 nm检测波长检测6-苄氨基嘌呤(6-BA)、萘乙酸(NAA)、吲哚丁酸(IBA)。结果显示:3种植物生长调节剂的质量浓度在0.05~28.00 mg·L^-1内与其对应的峰面积呈线性关系,检出限(3S/N)为0.044 5~0.085 5 mg·kg^-1。按标准加入法进行回收试验,回收率为97.3%~103%,测定值的相对标准偏差(n=5)为0.42%~2.2%。采用121 ℃蒸汽对MS培养基灭菌20 min后,6-BA、NAA的检出量较灭菌前的没有明显变化,IBA的检出量明显下降,且灭菌后检出量减少量和灭菌前的检出量呈线性正相关。

Sample of MS culture medium had been mashed and mixed, and an aliquot (10 g) was taken and mixed with 10 mL of acetonitrile. The mixture was shaken for 20 min, and 1.14 g of sodium chloride and 2.24 g of anhydrous sodium sulfate were added. The mixture was shaken for 20 min, and centrifuged for 5 min. The supernatant was filtered through a 0.22 μm filter membrane, and the filtrate was introduced into the high performance liquid chomatograph. Separation was carried out on the InertSustain C₁₈ column (150 mm×4.6 mm, 5 μm) by gradient elution with mixed solutions composed of acetonitrile and phosphate buffer solution (pH 3.5) at various volume ratios, and 6-benzylaminopurine, naphthalene acetic acid and indole butyric acid were detcted at detection wavelengths of 272, 221, 223 nm, respectively. It was shown that linearity relationships between values of mass concentration and peak area of the 3 plant growth regulators were kept in the range of 0.05-28.00 mg·L^-1, with detection limits (3S/N) in the range of 0.044 5-0.085 5 mg·kg^-1. Test for recovery was made by standard addition method, giving values of recovery in the range of 97.3%-103%, and RSDs (n=5) of the determined values ranged from 0.42% to 2.2%. After the culture medium was sterilized at 121 ℃ for 20 min, there was no significant change in the detection amounts of 6-BA and NAA compared with those before sterilization. The detection amount of IBA decreased obviously after sterilization, which reduced amounts of the detection amount after sterilization had linear positive correlation with detection amounts before sterilization.