Nowadays, monitoring focuses on the primary compounds and does not include degradation products formed during various biological and chemical processes. Transformation products may have the same effects to human health and the environment or sometimes they can be more toxic than the parent compound. Unfortunately, knowledge about the formation of degradation products is still limited, however, can be very important for the environmental risk assessment. Firstly, the photodegradation kinetic of amlodipine was investigated in two experimental conditions: during the exposure to solar radiation and during the exposure to the light emitted by the xenon lamp. In all cases degradation of amlodipine followed a pseudo-first-order kinetics. In the next step, identification of transformation products of amlodipine formed during the exposure to xenon lamp irradiation was performed using ultra high performance liquid chromatography quadrupole time-of-flight mass spectrometry (UHPLC-QTOF-MS). As a result sixteen photoproducts were identified, their structures were elucidated and ultimately the transformation pathway was proposed. Fifteen compounds (out of 16 photoproducts) were newly identified and reported here for the first time; some of those compounds were formed from the first photoproduct, amlodipine pyridine derivative. Several analytes were formed only in acidic or basic conditions. Furthermore, the occurrence of amlodipine and its identified degradation products was investigated in environmental waters. Only one out of 16 compounds was found in wastewater effluent. The possibility of the sorption of examined analytes to sewage sludge particles was discussed based on QSAR.
如今,监测的重点是原生化合物,而不包括在各种
生物和
化学过程中形成的降解产物。降解产物可能对人类健康和环境产生相同的影响,有时甚至比母体化合物毒性更大。遗憾的是,有关降解产物形成的知识仍然有限,但这对环境风险评估却非常重要。首先,在两种实验条件下研究了
氨氯地平的光降解动力学:暴露在太阳辐射下和暴露在
氙灯发出的光下。在所有情况下,
氨氯地平的降解都遵循假一阶动力学。下一步,使用超高效
液相色谱-四极杆飞行时间质谱(UHPLC-QTOF-MS)对
氙灯照射过程中形成的
氨氯地平转化产物进行了鉴定。结果确定了 16 种光反应产物,阐明了它们的结构,并最终提出了转化途径。在 16 种光反应产物中,有 15 种化合物是新发现的,并在此首次报道;其中一些化合物是由第一种光反应产物
氨氯地平吡啶衍生物形成的。有几种分析物仅在酸性或碱性条件下生成。此外,还调查了环境
水体中
氨氯地平及其降解产物的存在情况。在废
水中只发现了 16 种化合物中的一种。在 Q
SAR 的基础上讨论了污
水污泥颗粒吸附受检分析物的可能性。