Aminoglycosides are broad-spectrum antibiotics often employed to combat Gram-negative bacterial infections. A technique based on electrospray-ionization mass spectrometry (ESI-MS) was developed for rapid determination of aminoglycosides. This method, which does not require prior chromatographic separation, or derivatization and extensive sample preparation steps, was deployed to estimate gentamicin, tobramycin, and amikacin in pharmaceutical formulations. Upon gas-phase collisional activation, protonated gentamicin, tobramycin, and amikacin undergo a facile loss of their respective “C” ring moiety to produce characteristic ions of m/z 322, 324, and 425, respectively. The mass spectral peak intensities for these specific product ions were monitored either by a flow-injection analysis selected-ion monitoring (FIA-SIM) time-intensity method or by a mass spectrometric internal-standard method. The linear dynamic ranges of detection for both methods were evaluated to be 10–1000 ng/mL for gentamicin, 25–2500 ng/mL for tobramycin, and 10–1000 ng/mL for amikacin. The internal-standard mass spectrometric method afforded lower intra-day and inter-day variations (2.3–3.0% RSD) compared to those from FIA-SIM method (4.5–5.0% RSD). This method was applied as a potential alternative procedure to determine gentamicin in commercial pharmaceutical samples and to monitor the release of gentamicin from “self-defensive” tannic acid-based layer-by-layer films into phosphate buffer solutions at different pHs.

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电喷雾电离质谱法快速测定药物制剂中的氨基糖苷类

氨基糖苷类是广谱抗生素，常用于对抗革兰氏阴性细菌感染。开发了一种基于电喷雾电离质谱 (ESI-MS) 的技术，用于快速测定氨基糖苷类。这种方法不需要事先进行色谱分离或衍生化和大量的样品制备步骤，用于评估药物制剂中的庆大霉素、妥布霉素和阿米卡星。在气相碰撞活化后，质子化庆大霉素、妥布霉素和阿米卡星容易丢失各自的“C”环部分，分别产生 m/z 322、324 和 425 的特征离子。这些特定产物离子的质谱峰强度通过流动注射分析选择离子监测 (FIA-SIM) 时间强度方法或质谱内标方法进行监测。两种方法的线性动态检测范围经评估为庆大霉素 10-1000 ng/mL、妥布霉素 25-2500 ng/mL 和阿米卡星 10-1000 ng/mL。与 FIA-SIM 方法（4.5-5.0% RSD）相比，内标质谱方法提供了更低的日内和日间变化（2.3-3.0% RSD）。该方法被用作一种潜在的替代方法，用于测定商业药物样品中的庆大霉素，并监测庆大霉素从“自卫”单宁酸层层薄膜中释放到不同 pH 值的磷酸盐缓冲溶液中。