Method and apparatus for spectrometric measurement of particulate surfaces

• US 5,469,255 A
• Filed: 01/27/1994
• Issued: 11/21/1995
• Est. Priority Date: 01/28/1993
• Status: Expired due to Term

• Current Assignee: Hiroshi Masuhara, Keiji Sasaki, Kenji Kamada, Noboru Kitamura
• Original Assignee: Hiroshi Masuhara, Keiji Sasaki, Kenji Kamada, Noboru Kitamura
• Inventors: Kitamura, Noboru, Masuhara, Hiroshi, Kamada, Kenji, Sasaki, Keiji
• Primary Examiner(s): EVANS, FANNIE L
• Application Number:
  US08/186,991
• Time in Patent Office: 663 Days
• Field of Search: 356/300, 356/317, 356/318, 356/417, 250/458.1, 250/459.1, 250/461.1, 250/461.2
• US Class Current: 356/300
• CPC Class Codes: G01N 15/00 Investigating characteristics of particles; Investigating permeability, pore-volume or surface-area of porous materials identification of microorganisms C12Q
• CPC Class Codes: G01N 2021/637 Lasing effect used for analysis
• CPC Class Codes: G01N 21/636 using an arrangement of pump beam and probe beam; using the measurement of optical non-linear properties; non-linear optics per se G02F1/35

Abstract

A method of spectrometry is disclosed for measuring transient absorbance and transient absorption spectrum of a substance to be measured at interfaces in liquid phase of particulates containing a fluorescent pigment and the substance to be measured by the utilization of optical resonance phenomenon. An apparatus for carrying out the method is also disclosed and comprises: (a) a pulse laser oscillator for exciting the fluorescent pigment and the substance to be measured, respectively; (b) an optical delay device for causing delay of any one of pulse laser beams of two kinds of wavelengths generated by the pulse laser oscillator; (c) a microscope system for condensing laser beams generated by the pulse laser oscillator and irradiating the condensed beams to the sample; and (d) a detector for detecting light emission of the sample. According to the method of the present invention, it is possible to measure transient absorbance and transient absorption spectrum at a high sensitivity even when particulates containing the substance to be measured in liquid phase are present.

Claims

1. A method for spectrometric measurement of particulate surfaces of a particulate substance, comprising the steps of:

doping the particulate substance with a fluorescent substance;

irradiating a light beam onto the particulate substance doped with the fluorescent substance; and

measuring transient absorbance and transient absorption spectrum of the particulate substance at particulate interfaces in liquid phase by detecting optical resonance phenomena of the irradiated particulate substance and the irradiated fluorescent substance.

2. A method as claimed in claim 1, wherein the optical resonance phenomenon of the irradiated particulate substance is the status of laser oscillation.

3. A method as claimed in claim 2, wherein said step of measuring is conducted by optically trapping the particulate substance.

4. A method as claimed in claim 1, wherein said step of measuring is conducted by optically trapping the particulate substance.

5. A spectrometric apparatus for measuring transient absorbance and transient absorption spectrum of a particulate substance at particulate interfaces in liquid phase, wherein the particulate substance is doped with a fluorescent pigment, by the utilization of optical resonance phenomena, said apparatus comprising:

(a) a pulse laser oscillator for generating laser beams of two wavelengths and exciting the fluorescent pigment and the substance to be measured, respectively;

(b) an optical delay device for causing delay of laser beams of one of the two wavelengths generated by said pulse laser oscillator;

(c) a microscope system for condensing laser beams generated by the pulse laser oscillator and irradiating the condensed beams to the particulate substance and the fluorescent pigment; and

(d) a detector for detecting light emission of the particulate substance and the fluorescent pigment.