[Determination of 13 prohibited alkaloids in essential oil-based cosmetics by ultra performance liquid chromatography-tandem mass spectrometry combining QuEChERS purification].

内容摘要

Alkaloids represent a class of naturally-occurring nitrogen-containing compounds widely distributed across diverse plant species. Owing to their well-documented potential to induce adverse effects on human health， certain alkaloids are explicitly prohibited from being used in cosmetic formulations. The escalating global popularity of essential oil-based cosmetics， which commonly incorporate complex botanical extracts， presents a potential avenue for the inadvertent introduction of these prohibited substances. Consequently， the development of robust， sensitive， and efficient analytical methods for their monitoring is of utmost significance for consumer safety and regulatory compliance. This study devises a reliable， high-throughput approach for the simultaneous determination of 13 prohibited alkaloids in essential oil-based cosmetics. It integrates optimized QuEChERS sample preparation with ultra performance liquid chromatography-tandem mass spectrometry （UPLC-MS/MS）. The sample preparation procedure was meticulously designed to maximize efficiency and minimize analyte loss. Chromatographic separation was accomplished on a Waters ACQUITY UPLC HSS T3 column （100 mm × 2.1 mm， 1.8 μm） maintained at a constant temperature of 30 ℃. The mobile phase was composed of （A） acetonitrile and （B） 0.1% （volume fraction） formic acid aqueous solution. A gradient elution program was implemented at a stable flow rate of 0.3 mL/min according to the following profile： an initial 5， a linear increase to 15 （0-2 min）， a rapid rise to 70 （2-4.5 min）， followed by an immediate reversion to the initial 5 （4.5-5.5 min）， which was maintained for re-equilibration until 7.0 min. The injection volume was 5 µL. Detection and quantification were conducted using a triple quadrupole mass spectrometer equipped with an electrospray ionization （ESI） source operating in positive ion mode （ESI+）. Data acquisition was carried out in the multiple reaction monitoring （MRM） mode to ensure superior specificity and sensitivity. For each of the 13 alkaloids， two specific ion transitions were monitored： one for quantitative analysis and the other for confirmatory identification. The method was rigorously validated in accordance with accepted analytical guidelines. All 13 target alkaloids displayed excellent linearity within a mass concentration range of 0.2 to 50 ng/mL， with correlation coefficients （R2） consistently exceeding 0.99. The limits of detection （LODs） and limits of quantification （LOQs）， determined with acceptable accuracy and precision， ranged from 1 µg/kg to 4 µg/kg and 2 µg/kg to 10 µg/kg， respectively. Method accuracy and precision were assessed through recovery tests at three spiking levels， with six replicates at each level. The mean recoveries for all analytes ranged from 83.9% to 119.1%， with associated relative standard deviations （RSDs） all being ≤7.3%， validating the method's high reliability and repeatability. Systematic evaluation indicated that the matrix effects for the 13 analytes were negligible； hence， the solvent calibration curve was adopted for quantitative analysis. The practical applicability of the validated method was demonstrated through the analysis of 50 batches of commercially available essential oil-based cosmetics. This market survey encompassed 15 products specifically marketed for infants or children and 35 products intended for adult use. As a result， none of the 13 target prohibited alkaloids were detected in any of the tested samples above their respective LOQs. A particularly notable accomplishment of this work is the successful development of a sensitive and reliable quantification strategy for oleandrin， a potent cardiotoxic alkaloid for which standardized detection methods in complex cosmetic matrices such as essential oils have been conspicuously absent. In conclusion， this study successfully establishes a simple， rapid， sensitive， and robust QuEChERS-UPLC-MS/MS method. It is comprehensively validated and clearly well-suited for the routine screening， risk monitoring， and quality control of 13 prohibited alkaloids in a wide array of essential oil-based cosmetics. The method offers reliable technical support for regulatory bodies to enforce safety standards and for manufacturers to ensure the safety and compliance of their products， thereby effectively contributing to the protection of consumer health. 生物碱是一类广泛存在于植物中的天然化合物，部分生物碱因其潜在的毒性已被明令禁止在化妆品中添加。随着精油类化妆品的普及，其植物来源成分可能引入禁用生物碱，带来安全隐患，因此建立快速、准确的分析方法对产品安全风险评估具有重要意义。本文开发了一种基于QuEChERS前处理结合超高效液相色谱-串联质谱（UPLC-MS/MS）的分析方法，用于同步测定精油类化妆品中13种禁用生物碱。样品经含0.1%甲酸的甲醇溶液超声提取，QuEChERS粉末净化后无需浓缩，直接进样分析；采用Waters ACQUITY UPLC HSS T3色谱柱（100 mm×2.1 mm， 1.8 μm）分离，以乙腈和0.1%甲酸水溶液为流动相进行梯度洗脱，电喷雾电离正离子模式（ESI+）和多反应监测（MRM）进行定性与定量分析。该方法在0.2~50 ng/mL范围内线性关系良好，相关系数均大于0.99，检出限（LOD）为1~4 μg/kg，定量限（LOQ）为2~10 μg/kg。在3个加标水平下的平均回收率为83.9%~119.1%，相对标准偏差（RSD）不超过7.3%（n=6）。为考察方法的实用性和适用性，将该方法用于50批市售精油化妆品中13种禁用生物碱的检测，样品包括15批宣称婴幼儿使用或儿童产品以及35批成人用精油产品。结果显示，所有样品中均未检出本方法所涵盖的13种禁用生物碱。本方法操作简便，灵敏度高，重复性好，适用于精油类化妆品中多种禁用生物碱的高通量筛查与检测，其中欧夹竹桃苷检测方法的建立为该领域检测技术的发展提供了新的思路，为化妆品质量控制和消费者安全提供了可靠的技术支撑。