Abstract:
Supplementing fish oil is one of the strategies to reduce the risk of cardiovascular disease, the leading cause of death around the world. Contradictorily, fish oil may also contain trimethylamine-N-oxide, a recently emerged risk factor for cardiovascular disease, as well as one of its precursors, trimethylamine. A method suitable for routine quantification of trimethylamine-N-oxide and trimethylamine in fish oil with a quick and easy liquid extraction without derivatization has been developed. Liquid chromatography with tandem mass spectrometry detection was employed along with a zwitterionic hydrophilic interaction liquid chromatography column and a gradient elution with eluents containing 50 mmol/L of ammonium formate. An internal standard (triethylamine) was used for quantification by mass spectrometry with an external calibration. The assay proved high linearity in the ranges of 10 to 100 ng/mL and 100 to 1000 ng/mL for trimethylamine-N-oxide and trimethylamine, respectively. The lowest limit of quantification was determined to be 100 µg/kg for trimethylamine and 10 µg/kg for trimethylamine-N-oxide, with the limit of detection at 5 µg/kg and 0.25 µg/kg, respectively. Accuracy ranged from 106-119%. Precision was below 7% the relative standard deviation for both analytes. The method was successfully applied for the determination of trimethylamine-N-oxide and trimethylamine contents in nine commercially available liquid fish oils and three commercially available fish oil capsules, showing that trimethylamine and trimethylamine-N-oxide are not present in highly refined fish oils.
摘要:
补充鱼油是降低心血管疾病风险的策略之一,全世界死亡的主要原因。矛盾的是,鱼油也可能含有三甲胺-N-氧化物,最近出现的心血管疾病的危险因素,以及它的前身之一,三甲胺.已开发出一种适用于鱼油中三甲胺-N-氧化物和三甲胺的常规定量方法,该方法可以快速简便地提取而无需衍生化。使用具有串联质谱检测的液相色谱以及两性离子亲水相互作用液相色谱柱和含有50mmol/L甲酸铵的洗脱液的梯度洗脱。内标(三乙胺)用于通过具有外部校准的质谱进行定量。该测定法证明了三甲胺-N-氧化物和三甲胺在10至100ng/mL和100至1000ng/mL范围内的高线性,分别。三甲胺的最低定量限为100µg/kg,三甲胺-N-氧化物的最低定量限为10µg/kg,检出限为5µg/kg和0.25µg/kg,分别。准确度范围为106-119%。两种分析物的精确度均低于7%的相对标准偏差。该方法已成功用于九种市售液体鱼油和三种市售鱼油胶囊中三甲胺-N-氧化物和三甲胺的含量测定。表明三甲胺和三甲胺-N-氧化物不存在于高度精炼的鱼油中。