高灵敏多维谱学气体检测方法及其在慢性肾脏病早期筛查中的应用研究

Chronic kidney disease (CKD) is one of the severe diseases harmful to human health. Early diagnosis and treatment of CKD has very important practical meanings. In this project, a new method of highly sensitive multi-dimensional spectral gas detection, based on preconcentration, multi-capillary column and ion mobility spectrometry, was introduced for early screening of CKD. The new method aims to analyze CKD markers, such as creatinine, trimethylamine and ammonia of ppb level in exhaled breath, and detect metabolic markers such as isoprene, ketones, aldehydes and so on at the same time. The problem of simultaneous determination of multiple trace substances in mixed sample will be solved by high efficiency coupling of sample preconcentration and MCC injection. Because cholesterol metabolism and oxidative stress would change in the early stage of CKD, the information of trace substances linked to cholesterol metabolism and oxidative stress could be extracted from MCC-IMS “fingerprints” of exhaled breath from patients at early stage. In order to reduce individual differences and environmental impacts, early screening model of CKD will be constructed based on the multiple information of exhaled breath related to CKD, metabolism and oxidative stress. The project will provide new techniques and methods for the early non-invasive screening of CKD based on exhaled breath analysis.

慢性肾脏病（CKD）是严重危害人类健康的疾病之一，其早诊断、早治疗具有非常重要的现实意义。本项目针对CKD早期筛查，提出基于预富集多束毛细管柱（MCC）－离子迁移率谱（IMS）技术的高灵敏多维谱学气体检测方法，将样品预富集与MCC进样有机结合，解决混杂气体中多种痕量物质同时检测的难题，实现对呼出气体中ppb量级的肌酐、三甲胺和氨等CKD标志物以及异戊二烯、酮类、醛类等代谢标志物的高灵敏多维谱学检测。在此基础上，充分利用MCC－IMS可同时给出多种痕量成分定性定量信息的优势，根据早期CKD就会引起机体新陈代谢及氧化应激改变的生理学原理，从呼出气体的MCC-IMS“指纹图谱”提取反映肾脏及机体新陈代谢情况的多种痕量物质信息构建CKD早期筛查模型，减小个体差异及环境的影响，为基于呼出气体检测的CKD早期无创筛查提供新技术和新方法。

本项目针对疾病初筛需求，开展基于气相色谱—离子迁移谱（GC-IMS）的呼出气体检测研究。掌握了肌酐、三甲胺等疾病标志物的离子迁移谱检测方法，设计搭建了可实现肺泡气采集及痕量成分分离检测的GC-IMS呼气检测系统。基于呼出气体的GC-IMS谱图实现对慢性肾脏病（CKD）患者与健康人群的分类。.利用电晕放电—离子迁移谱（CD-IMS）实现对肌酐和三甲胺的检测。肌酐水溶液的CD-IMS检测限0.087 μmol/L，线性范围0.88 μmol/L ~ 8.80 μmol/L，验证了羟苯磺酸钙与维生素C对IMS检测肌酐不会造成明显干扰。三甲胺的CD-IMS理论检出限0.46ppb，线性范围5-100ppb，可以满足慢性肾病患者呼出气体中三甲胺浓度的检测需要。.研制了用于呼气检测的GC-IMS系统。在采样模块中通过监测呼出气体中CO2浓度变化控制采样泵工作实现肺泡气采集，并以GC、IMS谱学方法分别实现其中痕量成分的分离及高灵敏检测。.开展GC-IMS呼气检测的临床试验，研究了呼出气体指纹谱图信号处理方法和分类算法。实现慢性肾脏病（CKD）患者与健康人群的分类识别，其中随机森林模型分类准确率达到90%。表明GC-IMS在CKD早期呼气筛查方面具有较大的应用潜力。同时，随机森林模型可给出GC-IMS呼气谱图中特征峰与分类的相关性，为呼出气体中CKD标志物的确定提供依据。