Development And Application Of A Toxic Compounds Screening Library Using Liquid Chromatography And Time-of-Flight Mass Spectrometry

Toxicological screening for chemical food poisoning incident is always a big challenge in the field of analytical chemistry, due to not only the unknown non-target poisoning substance but the complex sample matrix. The study focused on the development of toxicological screening techniques. Poison screening library was established by using an ultra-performance liquid chromatography coupled with time-of-flight mass spectrometry (UPLC-TOF-MS), and then proper pretreatment procedures was considered for the preparation of the typical toxicological samples, such as blood, urine and drinking water, to find the target drugs. This will provide useful information for the response of poisoning incident. The main results are summarized as follows:1. A comprehensive poison screening library was developed using UPLC-TOF-MS and Masslynx software, including a LC mass spectrum library and a TXT file library based on the accurate mass fragment information. The whole library comprised1196hazard compounds, such as pesticides, poison, drugs, and narcotics etc. It could achieve automated screening of poison by means of the identification and searching function of Masslynx software.2. A rapid and simple analytical method was established for210pesticides screening in drinking water via online-solid phase extraction (Online SPE) followed UPLC-TOF-MS determination and a posiive software analysis, in which the acquired mass data was analyzed and compared with the developed library. As a result,194pesticides (92%appropriately) presented the detection limits (LOD) of no more than100ng/L. Most of the analytes (>70%) approached good recoveries, higher than80%, at two different spiking levels, with the relative standard derivations (RSDs, n=6) less than30%. The method can be used to the screen of pesticides in drinking water.3. A compehensive screening method was estabolished for133typical drug and toxic compounds analysis in urine and serum samples. Two sample preparation methods, including direct extraction by acetonitrile and QuEChERS method, were compared in term of LOD, matrix effect, recovery and reproducibility of the whole procedure. The result showed that125out of the133analytes demonstrated acceptable recoveries (>80%) with the QuEChERS method, which was more sensitive, more reliable and more suitable for the poison screening in urine and serum samples.