title: First signal from a broadband cryogenic preamplifier cooled by circulating liquid nitrogen in a 7 T Fourier transform ion cyclotron resonance mass spectrometer.
abstract: Despite the outstanding performance of Fourier transform ion cyclotron/mass spectrometry (FTICR/MS), the complexity of the cellular proteome or natural compounds presents considerable challenges. Sensitivity is a key performance parameter of a FTICR mass spectrometer. By improving this parameter, the dynamic range of the instrument can be increased to improve the detection signal of low-abundance compounds or fragment ion peaks. In order to improve sensitivity, a cryogenic detection system was developed by the KBSI (Korean Basic Science Institute) in collaboration with Stahl-Electronics (Mettenheim, Germany). A simple, efficient liquid circulation cooling system was designed and a cryogenic preamplifier implemented inside a FTICR mass spectrometer. This cooling system circulates a cryoliquid from a Dewar to the "liquid circulation unit" through a CF flange to cool a copper block and a cryopreamplifier; the cooling medium is subsequently exhausted into the air. The cryopreamplifier can be operated over a very wide temperature range, from room temperature to low temperature environments (4.2 K). First, ion signals detected by the cryopreamplifier using a circulating liquid nitrogen cooling system were observed and showed a signal-to-noise ratio (S/N) about 130% better than that obtained at room temperature.
authors.affiliation: Korea Basic Science Institute, 804-1, Ochang 363-883, Republic of Korea. cmc@kbsi.re.kr
authors.forename: Myoung Choul
authors.initials: MC
authors.lastname: Choi
authors.forename: Jeong Min
authors.initials: JM
authors.lastname: Lee
authors.forename: Se Gyu
authors.initials: SG
authors.lastname: Lee
authors.forename: Sang Hwan
authors.initials: SH
authors.lastname: Choi
authors.forename: Yeon Suk
authors.initials: YS
authors.lastname: Choi
authors.forename: Kyung Jae
authors.initials: KJ
authors.lastname: Lee
authors.forename: SeungYong
authors.initials: S
authors.lastname: Kim
authors.forename: Hyun Sik
authors.initials: HS
authors.lastname: Kim
authors.forename: Stefan
authors.initials: S
authors.lastname: Stahl
mesh_terms: D003080:Cold Temperature; D017357:Cyclotrons; D005583:Fourier Analysis; D013058:Mass Spectrometry / Q000379:methods*; D009584:Nitrogen / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared / Q000379:methods
chemical_list: D009584:Nitrogen