Chuzo Fujimoto

“Buffer memory” technique for the combination of micro-high-performance liquid chromatography and infrared spectrometry

Abstract The buffer memory technique was applied to the combination of micro-high-performance size-exclusion chromatography and Fourier transform infrared spectrometry. A series of polystyrene standards with known molecular weights was studied and the molecular weight calibration was established. Polyethylene glycol of unknown molecular weight was determined from the calibration. The utility of the technique is discussed.

An Interface for the Combination of Micro High-performance Liquid Chromatography and Infrared Spectrometry

Much work has been done in recent years on the combination of high performance liquid chromatography and infrared spectrometry. Such studies reported the use of either a solvent removal technique or a flow cell technique in which interferometric spectrometers have been used as the detector.

Liquid chromatography—spectrometry with the buffer-memory technique

Abstract The utility of the buffer-memory technique in quantitative detection of liquid chromatographic (LC) effluents is demonstrated. Sub-microgram detection limits appear feasible for non-volatile compounds. A comparison of the buffer-memory technique and conventional liquid chromatographic—infrared spectroscopic (LC—IR) technique is made. Samples deposited on a KBr plate with the buffer-memory technique can be directly used to obtain more information. In particular, the chromatograms obtained by IR and X-ray fluorescence spectroscopy can be helpful in predicting the bonding between organic ligands and metals. This is demonstrated by introducing organotransition-metal complexes into the LC columns.

Interfacing of inductively coupled plasma—atomic emission spectrometry to supercritical fluid chromatography for elemental detection

Abstract The interface between supercritical fluid chromatography and inductively coupled plasma—atomic emission spectrometry is described. A laboratory-made nebulizer, into which a restrictor made of a Pyrex glass capillary with an opening of 5 nm was built, was attached directly to an inductively coupled plasma—atomic emission spectrometry torch. The performance was evaluated by injecting ferrocene solutions into a “pseudo” microcolumn and monitoring the Fe emission line at 259.94 nm. The interface was applied for the separation of a synthetic mixture of ferrocenes on a packed microcolumn (25 cm x 1 mm I.D.).

Micro-High Performance Liquid Chromatography-Inductively Coupled Plasma Combination Technique in Analysis of Organometallic Compounds

The combination technique of micro-high performance liquid chromatography and inductively coupled plasma atomic emission spectrometry (micro-HPLC-ICP) is demonstrated in the separation of organometallic compounds. Problems relating to the interfacing between micro-HPLC and ICP-atomic emission spectrometry could be eliminated by utilizing the simple interfacing devices in both reversed and normal phase LC modes.

Microcolumn high-performance liquid chromatography—thin-layer chromatography—Fourier transform infrared spectrometry

Abstract A method is described for acquiring identifiable Fourier transform infrared (FTIR) spectra of well resolved chromatographic components. The technique involves the combination of high-performance liquid chromatography (HPLC) and thin-layer chromatography (TLC), each utilizing a different separation mode. In this way, the full identification power of FTIR can be realized for mixture analysis. In this particular work, microcolumn size-exclusion HPLC was followed by conventional silica gel TLC. Subsequently, the infrared spectra of each spot immobilized on the plate were measured by diffuse reflectance spectrometry. Spectral features of the eluates could be readily distinguished when 8 μg of each component were injected into the column. The feasibility of measuring submicrogram amounts of materials directly on a TLC plate was demonstrated.

Supercritical fluid chromatography-infrared spectroscopy of oligomers: use of buffer-memory technique

Abstract The feasibility of using the buffer-memory technique for supercritical fluid chromatography-infrared spectroscopy (SFC-IR) is demonstrated. The effluent from a microtubular packed SFC column was deposited onto a crystal (or crystals) of potassium bromide as a continuous, narrow band (width about 1 mm) with instantaneous elimination of the mobile phase. This technique is compatible with IR detection of medium polarity oligomers, separated by SFC with 10% ethanol in hexane as the mobile phase. Chromatographic resolution is maintained, even for closely separated peaks, and identifiable spectra of the peaks can be obtained from the plate.

The use of deuterated solvents in high-performance liquid chromatography-Fourier transform infrared spectrometry

SummaryDeuterated compounds have been used as mobile phases for microcolumn high-performance liquid chromatography (HPLC) employing flow-cell Fourier transform infrared spectroscopy for detection. Separations were carried out on adsorption, reversed-phase, non-aqueous size-exclusion and aqueous size-exclusion chromatographic columns. Due to the IR transparency of deuterated compounds in a C−H stretching region they represent nearly ideal eluents in terms of universal detection. In addition, due to the shift in the absorption wavenumber following deuteration, deuterated solvents allow FTIR detection of solutes in other regions, where otherwise it would be prohibited, or sensitivity sacrified by interfering solvent absorption.

Microcolumn liquid chromatography/Fourier transform infrared spectrometry interface using a potassium bromide disk

SummaryA redesigned interface is reported for use in the detection of microcolumn liquid chromatographic effluents with a Fourier transform infrared spectrometer. The solutes eluting from the column are continuously deposited onto a 50mm diameter KBr disk as a “buffer-memory”. The disk is rotated by a stepper motor with a controlling electronics. After the chromatographic run, the disk is simply transferred to the spectrometer and the transmission spectra are measured as the disk rotates. The use of such a large KBr disk as a substrate permits to obtain spectra of the components having a large capacity factor.

Microcolumn high-performance liquid chromatography with Fourier transform infrared spectrometric detection

Abstract The introduction of microcolumns has led to many significant developments in high-performance liquid chromatography-Fourier transform infrared spectrometry interfaces. In this article the current status of their development, their potential and their limitations are reviewed.