Deng Chunhui, Zhang Jie, Yu Xiaofeng, Zhang Wei, Zhang Xiangmin
Department of Chemistry, Fudan University, 220 Handan Road, Shanghai 200433, China.
J Chromatogr B Analyt Technol Biomed Life Sci. 2004 Oct 25;810(2):269-75. doi: 10.1016/j.jchromb.2004.08.013.
Analysis of breath acetone has been used as a diagnostic tool for diabetes. Due to its nature of volatility and activity, it is very difficult to accurately measure the concentration of acetone in human breath by gas chromatography-mass spectrometry (GC-MS). To overcome this problem, we developed a new method using GC-MS and solid-phase microextraction (SPME) with on-fiber derivatization to determine acetone in human breath. Breath gas from controls and diabetic patients was collected in 3-l Tedlar bags. O-2,3,4,5,6-(Pentafluorobenzyl) hydroxylamine hydrochloride (PFBHA) in solution was firstly adsorbed on the SPME fiber of 65 microm polydimethylsiloxane-divinylbenzene (PDMS-DVB), and then the fiber was further headspace exposed in exhaled gas in the Tedlar bag at 40 degrees C for 4 min. Finally, the formed acetone oxime on the fiber was desorbed and analyzed by GC-MS. Using external standard method, acetone in the human breath was quantitatively analyzed by measurement of its oxime. The method provided a low detection limit of 0.049 ppbv for acetone in breath, relative standard deviation (R.S.D.) value of 3.4%, excellent accuracy. In addition, the method required simple sample preparation and no organic solvent. Acetone in diabetic breath was found to be higher than 1.71 ppmv, while its concentration in normal breath was lower than 0.76 ppmv. The results show that GC-MS and SPME with on-fiber derivatization is a simple, rapid and sensitive and solvent-free method for determination of low concentration acetone in breath and analysis of breath acetone can be used as supplementary tool for diagnosis of diabetes.
呼气丙酮分析已被用作糖尿病的诊断工具。由于丙酮具有挥发性和活性，采用气相色谱-质谱联用仪（GC-MS）准确测量人体呼出气体中丙酮的浓度非常困难。为克服这一问题，我们开发了一种新方法，即采用GC-MS和固相微萃取（SPME）并结合纤维上衍生化技术来测定人体呼出气体中的丙酮。对照组和糖尿病患者的呼出气体收集于3升的 Tedlar 袋中。首先将溶液中的O-2,3,4,5,6-（五氟苄基）盐酸羟胺（PFBHA）吸附在65微米聚二甲基硅氧烷-二乙烯基苯（PDMS-DVB）的SPME纤维上，然后将该纤维于40℃在Tedlar袋中的呼出气体顶空中进一步暴露4分钟。最后，将纤维上形成的丙酮肟解吸并用GC-MS进行分析。采用外标法，通过测定其肟对人体呼出气体中的丙酮进行定量分析。该方法对呼出气体中丙酮的检测限低至0.049 ppbv，相对标准偏差（R.S.D.）值为3.4%，准确性良好。此外，该方法所需的样品制备简单且无需有机溶剂。发现糖尿病患者呼出气体中的丙酮含量高于1.71 ppmv，而正常呼出气体中丙酮的浓度低于0.76 ppmv。结果表明，GC-MS和纤维上衍生化的SPME是一种简单、快速、灵敏且无溶剂的方法，可用于测定呼出气体中的低浓度丙酮，呼气丙酮分析可作为糖尿病诊断的辅助工具。
