title: Ultrasonic nebulization extraction/low pressure photoionization mass spectrometry for direct analysis of chemicals in matrices.
abstract: A novel ultrasonic nebulization extraction/low-pressure photoionization (UNE-LPPI) system has been designed and employed for the rapid mass spectrometric analysis of chemicals in matrices. An ultrasonic nebulizer was used to extract the chemicals in solid sample and nebulize the solvent in the nebulization cell. Aerosols formed by ultrasonic were evaporated by passing through a transferring tube, and desolvated chemicals were ionized by the emitted light (10.6 eV) from a Krypton discharge lamp at low pressure (∼68 Pa). First, a series of semi/non-volatile compounds with different polarities, such as polycyclic aromatic hydrocarbons (PAHs), amino acids, dipeptides, drugs, nucleic acids, alkaloids, and steroids were used to test the system. Then, the quantification capability of UNE-LPPI was checked with: 1) pure chemicals, such as 9,10-phenanthrenequinone and 1,4-naphthoquinone dissolved in solvent; 2) soil powder spiked with different amounts of phenanthrene and pyrene. For pure chemicals, the correlation coefficient (R(2)) for the standard curve of 9,10-phenanthrenequinone in the range of 3 ng-20 μg mL(-1) was 0.9922, and the measured limits of detection (LOD) was 1 ng ml(-1). In the case of soil powder, linear relationships for phenanthrene and pyrene from 10 to 400 ng mg(-1) were obtained with correlation coefficients of 0.9889 and 0.9893, respectively. At last, the feasibility of UNE-LPPI for the detection of chemicals in real matrices such as tablets and biological tissues (tea, Citrus aurantium peel and sage (Salvia officinalis) leaf) were successfully demonstrated.
authors.affiliation: National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, Anhui 230029, People's Republic of China.
authors.forename: Chengyuan
authors.initials: C
authors.lastname: Liu
authors.affiliation: National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, Anhui 230029, People's Republic of China.
authors.forename: Yanan
authors.initials: Y
authors.lastname: Zhu
authors.affiliation: National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, Anhui 230029, People's Republic of China; Power Machinery and Engineering of Ministry of Education, Shanghai Jiao Tong University, Shanghai 200240, People's Republic of China.
authors.forename: Zhongyue
authors.initials: Z
authors.lastname: Zhou
authors.affiliation: National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, Anhui 230029, People's Republic of China; Power Machinery and Engineering of Ministry of Education, Shanghai Jiao Tong University, Shanghai 200240, People's Republic of China.
authors.forename: Jiuzhong
authors.initials: J
authors.lastname: Yang
authors.affiliation: National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, Anhui 230029, People's Republic of China; Power Machinery and Engineering of Ministry of Education, Shanghai Jiao Tong University, Shanghai 200240, People's Republic of China.
authors.forename: Fei
authors.initials: F
authors.lastname: Qi
authors.affiliation: National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, Anhui 230029, People's Republic of China. Electronic address: panyang@ustc.edu.cn.
authors.forename: Yang
authors.initials: Y
authors.lastname: Pan
keywords: Low pressure; Mass spectrometry; Matrix; Photoionization; Ultrasonic nebulization (UN); Ultrasonic nebulization extraction (UNE)