Arkray, Inc.

Kyoto Daiichi Kagaku Co., Ltd.

Toshihisa Inoue

Hisashi Sakamoto

Takeshi Sakura

Norimasa Noda

Kaori Kurata

The ion activity-measuring device of the present invention is provided with a hydrophobic bridge of which portion contacting with a liquid reservoir is hydrophilic. The hydrophobic bridge is made of, for example, at least one selected from the group consisting of polyester, nylon, polypropylene, rayon and polyethylene, and is produced by treating a portion contacting with the liquid reservoir with a spreading accelerator. The spreading accelerator is at least one selected from the group consisting of a surfactant and a hydrophilic polymer. There is also provided a method for producing the above ion activity-measuring device, comprising embedding nonwoven fabric in the cover plate to bond the nonwoven fabric to the cover plate.

Ion activity-measuring device and method for producing the same

The present invention provides a reagent composition for measurement of ionic strength of liquid samples (especially for measurement of specific gravity of urine), which contains at least one phosphoric diester, at least one pH buffering agent, and at least one pH indicator. The present invention also provides a test tool containing the reagent composition which may be a test strip made by impregnation, coating, or printing of the composition. The reagent composition and the test tool are convenient and less susceptible to pH and temperature of the samples, measurement timing, etc. The compounds shown by the following general formula (1): ##STR1## wherein R.sub.1 and R.sub.2 in the formula (1) represent straight or branched alkyl groups containing 4-20 carbon atoms, phenyl groups which may be substituted, benzyl groups which may be substituted, or groups containing polyalkylene glycol chains, are preferable as a phosphoric diester.

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Kyoto, Japan

Toshihisa Inoue