A novel dried blood spots analysis combined with on-spot reaction for determination of trimethylamine N-oxide and its related compounds

• Published in: Talanta (Oxford) Vol. 210; p. 120639
• Main Authors: Cho, Hyun-Deok, Kim, Junghyun, Lee, Ji-Youn, Kim, Ye-Yeong, Lee, Yeoreum, Jo, Eunji, Suh, Joon Hyuk, Lee, Jaeick, Cha, Sangwon, Han, Sang Beom
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.04.2020
• Subjects: Dried blood spots; LC–MS; On-spot reaction; Surrogate analyte approach; Trimethylamine N-oxide; TMAO; LLOQ; Trimethylamine N-oxide; DTT; CHL; GBB; NTS; SA; iPrBAc; DBS; DMPK-A; DMPK-B; BzBAc; DMPK-C; Surrogate analyte approach; EtBAc; On-spot reaction; DMG; LC–HRMS; AA; PBS; Dried blood spots; DSS; LC–MS; MeBAc; TMA; DMS; BET; TML; MMS; RF; CAR; tBuBAc; Hct; PhBAc; 903; HCY
• ISSN: 0039-9140; 1873-3573
• DOI: 10.1016/j.talanta.2019.120639

The application of dried blood spots in clinical research is becoming increasingly popular owing to its convenient collection, storage, and transportation compared to that of conventional biological samples. The potential of trimethylamine N-oxide and its related compounds as biomarkers for various cardiovascular diseases, such as atherosclerosis, stroke, thrombosis, and heart failure, was recently highlighted, which was the driving force behind the development of an analytical method to identify trimethylamine N-oxide and eight related compounds in dried blood spots. In the proposed method, a novel “on-spot reaction” approach was introduced to overcome the low loading efficiency of trimethylamine in dried blood spots. Upon the addition of 50 μL of blood onto the filter paper pretreated with dilute HCl, an acid–base neutralization reaction in the blood spots transformed the volatile trimethylamine to a salt. Next, a punched disc with a diameter of 6.0 mm was eluted by agitation with 20 mM ammonium formate for 10 min and derivatized with 1.0 M ethyl bromoacetate at 80 °C for 60 min. A surrogate analyte approach was employed for quantification of these endogenous compounds in the complex matrix. Analysis was carried out using zwitterionic hydrophilic interaction liquid chromatography–high-resolution mass spectrometry. The established method was validated and applied to monitor real samples from 30 clinical cases. The proposed new methodology based on dried blood spots could greatly improve the convenience, analytical sensitivity, and selectivity of cardiovascular disease testing. [Display omitted] •DBS-based method to detect trimethylamine N-oxide-related compounds was proposed.•A novel on-spot reaction can improve loading efficiency of trimethylamine in DBS.•Chemical derivatization and surrogate analyte approach were employed.•The established method was validated and successfully applied in 30 real samples.•This can provide a simple approach to regular check-up for cardiovascular disease.