Abstract: The present invention provides a mutant beetle luciferase and the like, having mutation in which the amino acid corresponding to valine at position 288 in the amino acid sequence of wild-type Photinus pyralis luciferase is isoleucine, leucine or phenylalanine, mutation in which the amino acid corresponding to leucine at position 376 in the aforementioned sequence is proline, mutation in which the amino acid corresponding to glutamic acid at position 455 in the aforementioned sequence is valine, alanine, serine, leucine, isoleucine or phenylalanine, or mutation in which the amino acid corresponding to glutamic acid at position 488 in the aforementioned sequence is valine, alanine, serine, leucine, isoleucine or phenylalanine, in the amino acid sequence encoding a wild-type beetle luciferase, and characterized in that a luminescence intensity due to a luciferin-luciferase luminescence reaction in a 0.9% by mass NaCl solution is 50% or more of that in a NaCl-free solution.

Abstract: The present invention provides a mutant beetle luciferase and the like, having mutation in which the amino acid corresponding to valine at position 288 in the amino acid sequence of wild-type Photinus pyralis luciferase is isoleucine, leucine or phenylalanine, mutation in which the amino acid corresponding to leucine at position 376 in the aforementioned sequence is proline, mutation in which the amino acid corresponding to glutamic acid at position 455 in the aforementioned sequence is valine, alanine, serine, leucine, isoleucine or phenylalanine, or mutation in which the amino acid corresponding to glutamic acid at position 488 in the aforementioned sequence is valine, alanine, serine, leucine, isoleucine or phenylalanine, in the amino acid sequence encoding a wild-type beetle luciferase, and characterized in that a luminescence intensity due to a luciferin-luciferase luminescence reaction in a 0.9% by mass NaCl solution is 50% or more of that in a NaCl-free solution.

Abstract: To provide an oil type discrimination method and an oil type discriminator capable of accurately discriminating a type of oil even when light-shielding components exist in the oil and of preventing in advance erroneous discrimination of a mixture of oil. There are provided step S1 in which the transmission spectrum of near infrared light is measured, step S2 in which the transmission spectrum is converted into an absorbance spectrum, a first discrimination step S3 in which between gasoline type and non-gasoline type is discriminated by comparing the difference in absorbance between two wavelengths existing in the vicinities of respective attribute wavelengths of predetermined chemical bonds with 0.

Abstract: To provide an oil type discrimination method and an oil type discriminator capable of accurately discriminating a type of oil even when light-shielding components exist in the oil and of preventing in advance erroneous discrimination of a mixture of oil. There are provided step S1 in which the transmission spectrum of near infrared light is measured, step S2 in which the transmission spectrum is converted into an absorbance spectrum, a first discrimination step S3 in which between gasoline type and non-gasoline type is discriminated by comparing the difference in absorbance between two wavelengths existing in the vicinities of respective attribute wavelengths of predetermined chemical bonds with 0.

Abstract: It is an object of the present invention to provide an electrochemical sensor which can prevent occurrence of cracks at the welding portion between a support tube made of lead-free glass and a sensitive glass membrane or ceramics, and a method for manufacturing the same. The electrochemical sensor 100 has a configuration such that the sensitive glass membrane 2A is welded to the support tube 1 made of lead-free glass with a lead glass layer 3A between the sensitive glass membrane 2A and the support tube 1. According to the present invention, there is also provided the electrochemical sensor in which the ceramics 2B for a junction is welded to the support tube 1 made of lead-free glass with a lead glass layer 3B between the ceramics 2B and the support tube 1.

Abstract: A method and an apparatus are provided for measuring trace ingredients in water, which make it possible to perform detection and quantitative determination of silica, phosphorus or arsenic in a sample solution. The method includes adding a molybdate ion to a sample solution under an acidic condition, then adding a fluorescent counter cationic pigment thereto, and measuring the time required for the fluorescence emitted by the resultant solution to be attenuated to a prescribed intensity. The measuring apparatus includes an excitation light source which irradiates excitation light to the above-modified solution; a fluorescence detector which detects the fluorescence emitted by the solution; means for measuring the time required for the fluorescence detected by the fluorescence detector to be attenuated to a prescribed intensity; and control means for determining the concentration of silica, phosphorus or arsenic in the sample solution from the time measurement.

Abstract: The present invention relates to a method and apparatus for measuring the organic carbon content (TOC) in a test liquid by irradiating the test liquid, such as ultrapure water, with ultraviolet radiation and measuring the conductivity of the test liquid that changes due to the produced organic acids and carbon dioxide. After the test liquid is irradiated for a fixed time interval with ultraviolet light in an oxidization process vessel, the irradiation is stopped. The flow rate of the test liquid is such that a portion of test liquid is present that has received the complete irradiation from the commencement to the extinguishing of the lighting of the ultraviolet light source.