溶剂对醋酸奥曲肽HPLC色谱行为的影响

Effects of solvents on chromatographic behavior of octreotide acetate in HPLC

目的考察HPLC中不同进样溶剂对醋酸奥曲肽色谱行为的影响,并分析其产生原因。方法采用HPLC法及紫外分光光度法。色谱条件:色谱柱为Diamonsil C18柱(4.6 mm×250 mm,5μm),流动相为体积分数0.1%三氟乙酸-乙腈(体积比7:3),检测波长为215 nm,柱温为30℃,流速为1.0 mL.min-1,进样量为20μL。结果同一质量浓度醋酸奥曲肽溶于不同的进样溶剂中进行HPLC分析发现,进样溶剂不同导致醋酸奥曲肽色谱峰面积不同。当进样溶剂为乙醇-水体系时,同一质量浓度醋酸奥曲肽色谱峰面积随乙醇体积分数的增大而减小,且当乙醇体积分数小于40%时峰面积变化不明显,大于40%时变化显著。此外,低(20 mg.L-1)、中(40 mg.L-1)、高(60 mg.L-1)3种质量浓度的醋酸奥曲肽其色谱峰面积随进样溶剂中乙醇体积分数变化而变化的趋势相一致。当进样溶剂分别为体积分数0%、40%、80%及100%的乙醇时,醋酸奥曲肽在质量浓度为10～60 mg.L-1内与峰面积均呈现良好的线性关系,相关系数r分别为0.999 9、0.999 9、0.999 3、0.999 2。紫外检测结果显示,在2种检测波长(215、280 nm)下,随着溶剂中乙醇体积分数的升高,醋酸奥曲肽紫外吸光度值增大。结论相同色谱条件下,醋酸奥曲肽色谱峰面积随进样溶剂的极性降低而减小,造成这种现象的原因是当进样溶剂强度大于流动相时,部分药物随着溶剂流出色谱柱而未被保留,从而导致药物主峰面积减小。

Objective To study the influences of different solvents for injection on chromatographic behavior of octreotide acetate, and analyze the reasons for this effect. Methods HPLC and UV spectrophotometry were used to determine the concentration of octreotide acetate. A Diamonsil C18 column（4. 6 mm × 250 mm, 5 μm）and the mobile phase of 0. 1% trifluoroacetic acid-acetonitrile（ V： V =70：30）were used at 30 ℃ with a flow rate of 1.0 mL. min-1 and an injection volume of 20 μL. The detection wavelength was set at 215 nm. Results The peak area of octreotide acetate varied with different solvents. When the concentration of ethanol increased, the peak area of octreotide acetate decreased. This trend was obvious as long as the vol- ume fraction of ethanol was greater than 40%. Octreotide acetate of different concentrations （20 mg. L-1, 40 mg. L - 1,60 mg. L - 1 ） had the same trend of the peak area. The linear concentration ranges of octreotide acetate in solutions of 0%, 40%, 80% or 100% ethanol were 10. 0- 60. 0 mg. L - 1, with r of 0. 999 9, 0. 999 9,0. 999 3 and 0. 999 2 ,respectively. The results of UV spectro hotometry show that UV absorbance of octreotide acetate increased with the increasing of the volume fraction of ethanol in solution, under both the 215 nm or 280 nm detection wavelength. Conclusions Under the same chromatographic conditions, chro- matographic peak area of octreotide acetate decreases with the decrease of polarity of solvents for injection, because when the strength of solvents for injection is larger than the mobile phase＇s, some drugs will be out of the column without being retained.