Chess E K, Thomas B L, Hendren D J, Bean R M
Pacific Northwest Laboratory, Richland, Washington 99352.
Biomed Environ Mass Spectrom. 1988 May 1;15(9):485-93. doi: 10.1002/bms.1200150905.
The electron impact (EI) mass spectra of the permethyl, peracetyl and per(trifluoroacetyl) derivatives of hydroxylated benzo[a]pyrene (B[a]P) metabolites were determined and the fragmentation chemistry producing the spectra elucidated. The metabolites investigated were: 3-hydroxy-B[a]P; 7,8-dihydro-7,8-dihydroxy-B[a]P; 7,8,9,10-tetrahydro-7,8,9-trihydroxy-B[a]P; and 7,8,9,10-tetrahydro-7,8,9,10-tetrahydroxy-B[a]P. In addition, the positive and negative methane chemical ionization spectra were determined for the derivatives of the BP-tetrol. The EI fragmentation patterns of the methylated metabolites that contained partially saturated rings were complex and, in the case of the di- and trimethoxy compounds, included apparent violations of the even-electron rule. The permethylated triol and tetrol cleaved through a retro-Diels-Alder reaction. The EI spectra of the peracetates were dominated by losses of acetic acid and ketene. The per(trifluoroacetyl) species fragmented by losing elements of trifluoroacetic acid, trifluoracetate radical and trifluoroacetyl. The spectra obtained from the permethylated tetrol permitted accurate prediction of the corresponding permethylated derivatives of tetrol metabolites of chrysene and benz[a]anthracene. The ability to predict spectra may be useful in trace analysis of hydrocarbon metabolites in biological samples.
测定了羟基化苯并[a]芘（B[a]P）代谢物的全甲基、全乙酰基和全（三氟乙酰基）衍生物的电子轰击（EI）质谱，并阐明了产生这些质谱的裂解化学过程。所研究的代谢物有：3-羟基-B[a]P；7,8-二氢-7,8-二羟基-B[a]P；7,8,9,10-四氢-7,8,9-三羟基-B[a]P；以及7,8,9,10-四氢-7,8,9,10-四羟基-B[a]P。此外，还测定了BP-四醇衍生物的正离子和负离子甲烷化学电离谱。含有部分饱和环的甲基化代谢物的EI裂解模式很复杂，对于二甲氧基和三甲氧基化合物而言，甚至出现了明显违反偶电子规则的情况。全甲基化的三醇和四醇通过逆狄尔斯-阿尔德反应裂解。全乙酰化物的EI谱主要以乙酸和乙烯酮的损失为主。全（三氟乙酰基）物种通过失去三氟乙酸、三氟乙酸根自由基和三氟乙酰基等成分而裂解。从全甲基化四醇获得的质谱允许准确预测苊和苯并[a]蒽的四醇代谢物的相应全甲基化衍生物。预测质谱的能力可能有助于生物样品中烃类代谢物的痕量分析。
