title: Black phosphorus-assisted laser desorption ionization mass spectrometry for the determination of low-molecular-weight compounds in biofluids.
abstract: Quantitative analysis of small molecules by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) has been a challenging task due to matrix-derived interferences in low m/z region and poor reproducibility of MS signal response. In this study, we developed an approach by applying black phosphorus (BP) as a matrix-assisted laser desorption ionization (MALDI) matrix for the quantitative analysis of small molecules for the first time. Black phosphorus-assisted laser desorption/ionization mass spectrometry (BP/ALDI-MS) showed clear background and exhibited superior detection sensitivity toward quaternary ammonium compounds compared to carbon-based materials. By combining stable isotope labeling (SIL) strategy with BP/ALDI-MS (SIL-BP/ALDI-MS), a variety of analytes labeled with quaternary ammonium group were sensitively detected. Moreover, the isotope-labeled forms of analytes also served as internal standards, which broadened the analyte coverage of BP/ALDI-MS and improved the reproducibility of MS signals. Based on these advantages, a reliable method for quantitative analysis of aldehydes from complex biological samples (saliva, urine, and serum) was successfully established. Good linearities were obtained for five aldehydes in the range of 0.1-20.0 μM with correlation coefficients (R (2)) larger than 0.9928. The LODs were found to be 20 to 100 nM. Reproducibility of the method was obtained with intra-day and inter-day relative standard deviations (RSDs) less than 10.4 %, and the recoveries in saliva samples ranged from 91.4 to 117.1 %. Taken together, the proposed SIL-BP/ALDI-MS strategy has proved to be a reliable tool for quantitative analysis of aldehydes from complex samples. Graphical Abstract An approach for the determination of small molecules was developed by using black phosphorus (BP) as a matrix-assisted laser desorption ionization (MALDI) matrix.
authors.affiliation: Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), Department of Chemistry, Wuhan University, Wuhan, Hubei, 430072, China.
authors.forename: Xiao-Mei
authors.initials: XM
authors.lastname: He
authors.affiliation: Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), Department of Chemistry, Wuhan University, Wuhan, Hubei, 430072, China. jding@whu.edu.cn.
authors.forename: Jun
authors.initials: J
authors.lastname: Ding
authors.affiliation: Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), Department of Chemistry, Wuhan University, Wuhan, Hubei, 430072, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Yu
authors.affiliation: Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), Department of Chemistry, Wuhan University, Wuhan, Hubei, 430072, China.
authors.forename: Dilshad
authors.initials: D
authors.lastname: Hussain
authors.affiliation: Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), Department of Chemistry, Wuhan University, Wuhan, Hubei, 430072, China. yqfeng@whu.edu.cn.
authors.forename: Yu-Qi
authors.initials: YQ
authors.lastname: Feng
mesh_terms: D000447:Aldehydes / Q000032:analysis / Q000097:blood* / Q000652:urine*; D006801:Humans; D007553:Isotope Labeling / Q000379:methods; D057230:Limit of Detection; D010758:Phosphorus / Q000737:chemistry*; D012463:Saliva / Q000737:chemistry; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*
chemical_list: D000447:Aldehydes; D010758:Phosphorus
keywords: Black phosphorus; MALDI matrix; Quantitative analysis; Quaternary ammonium compounds; Stable isotope labeling