Bartels M J, Timchalk C, Smith F A
Health and Environmental Sciences, Dow Chemical Company, Midland, Michigan 48674.
Biol Mass Spectrom. 1993 Mar;22(3):194-200. doi: 10.1002/bms.1200220309.
2,4-Toluenediamine (TDA) and 2,4-toluenediisocyanate (TDI) are metabolized in the Fischer 344 rat to monoacetyl-2,4-toluenediamine (Ac-TDA) and diacetyl-2,4-toluenediamine (Ac2-TDA). A gas chromatographic/tandem mass spectrometric (GC/MS/MS) method was developed to characterize the structure of the Ac-TDA metabolite (2-acetyl versus 4-acetyl), as a D3-diacetyl-TDA derivative. This method was also shown to be useful in the measurement of urinary levels of TDA, Ac-TDA and Ac2-TDA. Urine samples (1.0 g) were adjusted to pH 6.5-7.0, fortified with the internal standard D9-Ac2-TDA (D3-ring + D3-acetyl x 2) and extracted with ethyl acetate (2 x 2 ml). The extract residues were then derivatized with D6-acetic anhydride and analyzed via electron impact GC/MS/MS. MS/MS analysis of the D3-Ac2-TDA derivative of the two Ac-TDA isomers yielded different daughter ion spectra from the common parent ion (m/z 209). Analysis of urine samples from rats administered TDA (p.o., i.v.) and TDI (p.o., inhalation) indicated that all of the metabolic Ac-TDA from these test materials was the 4-acetyl-TDA isomer. Subsequent GC/MS analysis of the heptafluorobutyric acid (HFBA) derivative of this metabolite confirmed the MS/MS results. Selected ion monitoring of the M-acetyl daughter ions from the derivatized TDA, Ac-TDA and Ac2-TDA was shown to be a useful technique for quantitation of urinary levels of these compounds, with a detection limit of 35 ng g-1 urine for TDA and 10 ng g-1 urine for Ac-TDA and Ac2-TDA.
2,4 - 甲苯二胺（TDA）和2,4 - 甲苯二异氰酸酯（TDI）在费希尔344大鼠体内代谢生成单乙酰 - 2,4 - 甲苯二胺（Ac - TDA）和二乙酰 - 2,4 - 甲苯二胺（Ac2 - TDA）。开发了一种气相色谱/串联质谱（GC/MS/MS）方法，以D3 - 二乙酰 - TDA衍生物的形式表征Ac - TDA代谢物的结构（2 - 乙酰基对4 - 乙酰基）。该方法还被证明可用于测量尿液中TDA、Ac - TDA和Ac2 - TDA的水平。将尿液样本（1.0 g）调节至pH 6.5 - 7.0，加入内标D9 - Ac2 - TDA（D3 - 环 + D3 - 乙酰基×2），并用乙酸乙酯（2×2 ml）萃取。然后将萃取残余物用D6 - 乙酸酐衍生化，并通过电子轰击GC/MS/MS进行分析。两种Ac - TDA异构体的D3 - Ac2 - TDA衍生物的MS/MS分析产生了与共同母离子（m/z 209）不同的子离子光谱。对经口、静脉注射给予TDA以及经口、吸入给予TDI的大鼠的尿液样本分析表明，这些受试物产生的所有代谢性Ac - TDA均为4 - 乙酰基 - TDA异构体。随后对该代谢物的七氟丁酸（HFBA）衍生物进行的GC/MS分析证实了MS/MS结果。对衍生化的TDA、Ac - TDA和Ac2 - TDA的M - 乙酰基子离子进行选择离子监测被证明是一种用于定量这些化合物尿液水平的有用技术，TDA的检测限为35 ng g-1尿液，Ac - TDA和Ac2 - TDA的检测限为10 ng g-1尿液。
