高效液相色谱-串联质谱法同时测定发酵液中喷司他丁和2'-氨基-2'-脱氧腺苷

建立了高效液相色谱-串联质谱(HPLC-MS/MS)同时测定发酵液中喷司他丁和2'-氨基-2'-脱氧腺苷含量的方法。发酵液经高速离心、水溶液稀释、微孔过滤后进行HPLC-MS/MS分析测定。选用Waters Atlantis^® T3色谱柱(100 mm×2.1 mm, 5 μm)及其保护柱(5 mm×2.1 mm, 5 μm)进行分离,选择10 mmol/L甲酸铵(含0.1%甲酸)-甲醇(含0.02%甲酸)溶液为流动相进行梯度洗脱,流速为0.3 mL/min,柱温为25 ℃,进样量为10 μL。在电喷雾电离、正离子模式下收集数据,对目标化合物进行定性定量分析。喷司他丁定量离子对为m/z 269.17>153.20,碰撞能为11 V, 2'-氨基-2'-脱氧腺苷定量离子对为m/z 267.00>136.10,碰撞能为18 V。采用外标法对喷司他丁和2'-氨基-2'-脱氧腺苷定量分析。结果表明,喷司他丁和2'-氨基-2'-脱氧腺苷在1.0~250 μg/L范围内呈现出良好的线性关系,相关系数(R²)为0.9969~0.9996,相对标准偏差(RSD)为6.51%~8.35%(n=8)。在发酵液样品中进行加标水平为1.0、5.0和25 μg/L的添加回收试验(n=6),喷司他丁的回收率为97.94%~104.46%, RSD为3.74%~4.88%; 2'-氨基-2'-脱氧腺苷回收率为89.96%~107.21%, RSD为4.81%~13.29%。喷司他丁和2'-氨基-2'-脱氧腺苷的检出限为0.003~0.060 μg/L,定量限为0.010~0.200 μg/L。该文系统性地建立了基于HPLC-MS/MS测定发酵液中喷司他丁和2'-氨基-2'-脱氧腺苷的方法,在实际样品检测中,操作简便,准确度高,灵敏快速,有效克服了基质效应对目标化合物的影响,改善了目标化合物的峰形和稳定性,为从微生物发酵液中检测喷司他丁和2'-氨基-2'-脱氧腺苷提供了方法学基础和借鉴。

Simultaneous determination of pentostatin and 2'-amino-2'-deoxyadenosine in fermentation broth by high performance liquid chromatography-tandem mass spectrometry

An analytical method was established for the simultaneously determination the pentostatin and 2'-amino-2'-deoxyadenosine contents in fermentation broth by high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). After high-speed centrifugation, aqueous solution dilution, vortex shock, and microfiltration, the fermentation broth samples were analyzed by HPLC-MS/MS. The samples were separated on a Waters Atlantis^® T3 column (100 mm×2.1 mm, 5 μm) using a gradient elution program with 10 mmol/L ammonium formate (containing 0.1% formic acid) and methanol (containing 0.02% formic acid) as the mobile phases. Moreover, a chromatographic protection column (5 mm×2.1 mm, 5 μm) was added to preserve the column efficiency. The flow rate, column temperature, and injection volume were set at 0.3 mL/min, 25 ℃, and 10 μL, respectively. Qualitative and quantitative analyses of the target compounds were performed using an ESI⁺ source. MS parameters such as the collision energies and tube lens offsets of pentostatin and 2'-amino-2'-deoxyadenosine were optimized. The quantitative ion pairs of pentostatin and 2'-amino-2'-deoxyadenosine were m/z 269.17>153.20 and m/z 267.00>136.10, respectively; the corresponding collision energies were 11 V and 18 V. The external standard method was used for quantitative analysis. The established method was verified rigorously in terms of the linear range, limit of detection, limit of quantification, recovery rate, and precision. Pentostatin and 2'-amino-2'-deoxyadenosine showed good linear relationships in the range of 1.0-250 μg/L. The correlation coefficients ranged from 0.9969 to 0.9996, and the relative standard deviations (RSDs) ranged from 6.51% to 8.35% (n=8). This result indicated good accuracy and exactitude in the detection of the pentostatin and 2'-amino-2'-deoxyadenosine. The recoveries (n=6) at three spiked levels (1.0, 5.0, and 25 μg/L) were in the ranges of 97.94%-104.46% and 89.96%-107.21% for the pentostatin and 2'-amino-2'-deoxyadenosine, respectively; the corresponding RSDs were in the ranges of 3.74%-4.88% and 4.81%-13.29%. The limits of detection (LODs, S/N≥3) and limits of quantification (LOQs, S/N≥10) of the 2'-amino-2'-deoxyadenosine and pentostatin in the fermentation broth were 0.003-0.060 μg/L and 0.010-0.200 μg/L, respectively. The validated experimental method was used for the detection of actual samples, viz. the stored multiple pentostatin-producing mutagenic strains in our laboratory. The HPLC-MS/MS method for the determination of the pentostatin and 2'-amino-2'-deoxyadenosine in fermentation broth offered the advantages of small sampling volume, strong maneuverability, good stability, and high sensitivity. Compared with previously published methods, this systematically established and optimized method significantly reduced the detection time, and matrix effects were well suppressed. Moreover, the peak shape and stability of the target compounds were greatly improved. This method provides a methodological basis and meaningful reference for the detection of the pentostatin and 2'-amino-2'-deoxyadenosine in fermentation broth.