The Children's Hospital at Westmead Clinical School, University of Sydney, Sydney, Australia.
Department of Biochemistry, The Children's Hospital at Westmead, Sydney, Australia.
J Sep Sci. 2023 May;46(10):e2201003. doi: 10.1002/jssc.202201003. Epub 2023 Mar 15.
N,N-dimethylacetamide is an excipient used in intravenous busulfan formulations, a drug used in hematopoietic stem cell transplantation conditioning. The aim of this study was to develop and validate a liquid chromatography-tandem mass spectrometry method for simultaneous quantification of N,N-dimethylacetamide, and its metabolite N-monomethylacetamide in plasma from children receiving busulfan. A 4 μl aliquot of patient plasma was extracted using 196 μl 50% methanol solution and quantified against calibrators prepared in the extraction solvent given negligible matrix effects across three concentrations. [H ]-N,N-dimethylacetamide was used as an internal standard. Separation of N,N-dimethylacetamide and N-monomethylacetamide was achieved using a Kinetex EVO C18 stationary phase (100 mm × 2.1 mm × 2.6 μm) running an isocratic mobile phase of 30% methanol containing 0.1% formic acid at a flow of 0.2 ml/min over 3.0 min. The injection volume was 1 μl. Calibration curves for N,N-dimethylacetamide and N-monomethylacetamide were linear up to 1200 and 200 μg/L, respectively, with a lower limit of quantification 1 μg/L for both analytes. Calibrator accuracy and precision were within ± 10% of the test parameters across four concentration levels. Analytes were stable over 14 days at three different storage conditions. This method was successfully applied to measure N,N-dimethylacetamide and N-monomethylacetamide concentrations in a total of 1265 plasma samples from 77 children.
N,N-二甲基乙酰胺是静脉注射用白消安制剂中的赋形剂，白消安是用于造血干细胞移植预处理的一种药物。本研究旨在开发和验证一种同时定量检测接受白消安治疗的儿童血浆中 N,N-二甲基乙酰胺及其代谢物 N-单甲基乙酰胺的液相色谱-串联质谱法。从患者血浆中提取 4μl 等分试样，使用 196μl50%甲醇溶液进行提取，在 3 个浓度下，提取溶剂中的内标[H] -N,N-二甲基乙酰胺几乎没有基质效应。[H] -N,N-二甲基乙酰胺被用作内标。N,N-二甲基乙酰胺和 N-单甲基乙酰胺的分离是在 Kinetex EVO C18 固定相（100mm×2.1mm×2.6μm）上实现的，采用含有 0.1%甲酸的 30%甲醇作为等度流动相，流速为 0.2ml/min，洗脱时间为 3.0min。进样体积为 1μl。N,N-二甲基乙酰胺和 N-单甲基乙酰胺的校准曲线在 1200μg/L 和 200μg/L 范围内呈线性，两者的定量下限均为 1μg/L。在四个浓度水平下，校准剂的准确度和精密度均在测试参数的±10%范围内。分析物在三种不同储存条件下 14 天内稳定。该方法成功应用于 77 名儿童的 1265 份血浆样本中 N,N-二甲基乙酰胺和 N-单甲基乙酰胺浓度的测定。
