Fiorentino M L, Ghittori S, Pezzagno G
Dipartimento di Medicina Preventiva, Occupazionale e di Comunità dell'Università di Pavia.
Med Lav. 1990 Mar-Apr;81(2):107-18.
Benzene is a widely diffuse solvent (atmosphere, cigarette smoke, some foods); in the industrial environment benzene is currently present at concentrations of ppm. A valid method of biological monitoring that is easy to perform is needed for assessing occupational and non-occupational exposures. A new method has been developed to evaluate low concentrations of benzene in urine samples by means of a "dynamic" headspace (50 ml of urine in a 120 ml vial). The urine is saturated with anhydrous Na2SO4 in order to support the entrance of benzene in the air over the urine. The solvent is stripped from the urine surface and concentrated on an adsorbent substrate (Carbotrap 100 tube) by means of a suction pump (150 ml/min). A simultaneous intake of filtered air through a charcoal tube allows wash-up of the headspace. Benzene is thermically desorbed and injected in a column (Thermal tube desorber-Supelco; 370 degrees C thermal flash; borosilicate capillary glass column SPB-1 60 m length, 0.75 mm I.D., 1 micron film thickness; G.C. Dani 8580-FID). The detection limit of the method is about 50 ng/l and the variation coefficient is 4.7%. The method was checked on urine samples of 5 non-smokers and 5 smokers: mean values of 135 and 944 ng/l respectively were obtained. A further analysis on urine samples of 60 smokers revealed a significant relationship (p less than 0.001) between urinary benzene concentrations and C0 alveolar concentrations (r = 0.626). A close relationship between benzene exposure levels and urinary concentrations was found in a group of workers exposed to low environmental benzene concentrations (mean value 1200 micrograms/m3) (r = 0.763).
苯是一种广泛扩散的溶剂（存在于大气、香烟烟雾、某些食物中）；在工业环境中，苯目前的浓度为百万分之一。需要一种易于执行的有效生物监测方法来评估职业和非职业接触情况。已开发出一种新方法，通过“动态”顶空（在120毫升小瓶中加入50毫升尿液）来评估尿液样本中低浓度的苯。尿液用无水硫酸钠饱和，以促进苯进入尿液上方的空气中。溶剂从尿液表面被汽提，并通过抽吸泵（150毫升/分钟）浓缩在吸附底物（Carbotrap 100管）上。同时通过活性炭管吸入过滤空气，以清洗顶空。苯经热解吸后注入色谱柱（热解吸管 - Supelco；370℃热闪蒸；硼硅酸盐毛细管玻璃柱SPB - 1，长度60米，内径0.75毫米，膜厚1微米；气相色谱仪Dani 8580 - FID）。该方法的检测限约为50纳克/升，变异系数为4.7%。对5名不吸烟者和5名吸烟者的尿液样本进行了检测：分别得到平均值135和944纳克/升。对60名吸烟者的尿液样本进行的进一步分析显示，尿苯浓度与肺泡一氧化碳浓度之间存在显著关系（p小于0.001）（r = 0.626）。在一组暴露于低环境苯浓度（平均值1200微克/立方米）的工人中，发现苯暴露水平与尿液浓度之间存在密切关系（r = 0.763）。
