Patent Description:
Fourier transform infrared spectroscopy (FTIR) has been known as a method of analyzing an object. <CIT> describes an exemplary Fourier transform infrared spectrophotometer for performing this method. The Fourier transform infrared spectrophotometer includes an infrared source. Infrared rays emitted from the infrared source pass through a prescribed optical system and thereafter a sample is irradiated therewith. Infrared rays that have passed through the sample are detected by a detector.

In an example where an object to be measured is provided as being contained in a liquid, filter paper is impregnated with this liquid and measurement is conducted with this filter paper being adopted as a sample. After the filter paper is impregnated with the liquid containing the object and before measurement with a Fourier transform infrared spectrophotometer is conducted, the filter paper is dried. Drying, however, causes wrinkles in the filter paper. The filter paper where wrinkles were caused has a significantly irregular surface. Therefore, in an attempt to conduct measurement on this surface with the Fourier transform infrared spectrophotometer, it is difficult to adjust the focus. In some cases, measurement has to be conducted with the focus not sufficiently being adjusted, which results in poor accuracy in measurement data. Further prior art documents are <CIT>, <CIT>, <CIT>, <CIT>, <CIT> and <CIT>.

<CIT> discloses a holder for a membrane, the holder comprising a body including a vertically extending tubular portion, an O ring fixing the membrane in a flat state under tension by being fitted over the membrane to surround an outer side of the tubular portion while the membrane is carried on the vertically extending tubular portion of body.

An object of the present invention is to provide a holder for drying, a method of manufacturing a measurement sample, and a measurement method that allow highly accurate measurement with Fourier transform infrared spectroscopy.

This object is achieved by the subject-matters of the independent claims. Further advantageous modifications and embodiments of the invention are subject-matters of the dependent claims.

A holder for drying in a first embodiment based on the present invention will be described with reference to <FIG>. <FIG> shows a holder for drying <NUM> in the present embodiment.

Holder for drying <NUM> includes a first member <NUM> and a second member <NUM>. <FIG> shows a plan view of first member <NUM>. First member <NUM> includes an opening <NUM>. First member <NUM> includes a first tubular portion <NUM> that protrudes like a tube. First tubular portion <NUM> is in a shape of a circular tube. First tubular portion <NUM> includes a surface 31a at an upper end. As shown in <FIG>, first member <NUM> includes a second tubular portion <NUM> that protrudes in a direction opposite to first tubular portion <NUM>, in addition to first tubular portion <NUM>. Second tubular portion <NUM> includes a surface 32a at a lower end. First member <NUM> includes an annular projecting portion <NUM> that projects outward around an outer peripheral surface. In an example shown here, projecting portion <NUM> includes an upper surface 4a and a lower surface 4b. First member <NUM> is in a shape symmetric in an upward/downward direction. Opening <NUM> in first member <NUM> may be a through hole.

Second member <NUM> includes an upper end 52a and a lower end 52b. In the example shown here, upper end 52a and lower end 52b are flat surfaces, however, upper end 52a is not necessarily a flat surface. <FIG> shows a plan view of second member <NUM>. Second member <NUM> is annular. Second member <NUM> includes an opening <NUM>. Opening <NUM> is a through hole.

<FIG> shows a perspective view of holder for drying <NUM>. <FIG> and <FIG> show how holder for drying <NUM> is used. In <FIG>, wet filter paper <NUM> is placed on first tubular portion <NUM>. Filter paper <NUM> is impregnated with a liquid containing an object. The object is, for example, a fine solid. As shown with an arrow <NUM> in <FIG>, second member <NUM> is applied from above. Thus, first tubular portion <NUM> enters opening <NUM> in second member <NUM> while it pushes to bend filter paper <NUM>. As application of second member <NUM> ends, a state shown in <FIG> is set. <FIG> is a cross-sectional view of a state in which filter paper <NUM> is fixed to holder for drying <NUM>. In this state, filter paper <NUM> is in a flat state as being pulled toward an outer periphery at least at the upper surface of first tubular portion <NUM> and opening <NUM>.

Second member <NUM> can thus fix filter paper <NUM> impregnated with the liquid containing the object as being flat under tension by being fitted over filter paper <NUM> to surround an outer side of first tubular portion <NUM> while filter paper <NUM> is carried on first tubular portion <NUM>.

Holder for drying <NUM> is a jig for drying filter paper <NUM> to set the filter paper into a state available as a sample. As shown in <FIG>, after wet filter paper <NUM> is fixed, it is dried with an appropriate method. Holder for drying <NUM> where filter paper <NUM> is fixed may be left stand for natural drying, or may be placed in some drying chamber for a certain time period or longer. For example, hot air may be sent toward holder for drying <NUM> where filter paper <NUM> is fixed.

Holder for drying <NUM> in the present embodiment can fix filter paper <NUM> under tension by sandwiching filter paper <NUM> between first member <NUM> and second member <NUM>. Consequently, filter paper <NUM> can be dried as being fixed in a flat state. Therefore, this holder for drying <NUM> can make a sample with a flat surface, and highly accurate measurement with Fourier transform infrared spectroscopy can be conducted.

As shown in the present embodiment, preferably, first tubular portion <NUM> is in a shape of a circular tube. By adopting this construction, at the upper surface of filter paper <NUM>, the filter paper can be pulled equally toward the entire perimeter. First member <NUM> can conveniently be used regardless of an orientation thereof, because first tubular portion <NUM> is in the shape of the circular tube. First tubular portion <NUM> is in the shape of the circular tube.

As shown in the present embodiment, first member <NUM> includes annular projecting portion <NUM> around the outer peripheral surface and projecting portion <NUM> is arranged such that filter paper <NUM> is sandwiched between lower end 52b of second member <NUM> and upper surface 4a of projecting portion <NUM>. By adopting this construction, filter paper <NUM> can firmly be fixed by being sandwiched. Though an example in which lower end 52b of second member <NUM> is the flat surface is shown in the present embodiment, a similar effect not according to the invention is achieved even when lower end 52b of second member <NUM> is not the flat surface.

Though an example in which filter paper <NUM> impregnated with a liquid containing an object is prepared and second member <NUM> is fitted over filter paper <NUM> to surround the outer side of first tubular portion <NUM> while filter paper <NUM> is carried on first tubular portion <NUM> is described, this is merely by way of example. The order of operations is not limited as such. For example, filter paper <NUM> that has not yet been impregnated with a liquid containing an object may be prepared and second member <NUM> may be fitted over filter paper <NUM> to surround the outer side of first tubular portion <NUM> while filter paper <NUM> is carried on first tubular portion <NUM>. Thus, after filter paper <NUM> is fixed to holder for drying <NUM> and becomes flat, filter paper <NUM> may be impregnated with a liquid containing an object. Even in such a case as well, filter paper <NUM> can be dried while it is fixed in a flat state and a sample with a flat surface can be made.

The inventors prepared two types of filter paper <NUM> each impregnated with a liquid containing an object. From one type, a sample was made by drying with the use of holder for drying <NUM> in the present embodiment. From the other type, a sample was made by drying with a conventional method without the use of the holder. These two samples were used and subjected to measurement with Fourier transform infrared spectroscopy, and obtained data was compared. <FIG> shows measurement data obtained from the two samples. <FIG> shows a graph of absorbance for data A and B. Data A originated from the sample obtained with the use of holder for drying <NUM>. Data B originated from the sample obtained by drying with the conventional method. Data A was sufficient in intensity of absorbance, and a peak was readily observed. Data B was low in intensity of absorbance, and a peak tended to be ambiguous.

As set forth above, it could be confirmed that highly accurate measurement with Fourier transform infrared spectroscopy could be conducted by drying with holder for drying <NUM> in the present embodiment.

A method of manufacturing a measurement sample in a second embodiment based on the present invention will be described with reference to <FIG> shows a flowchart of the method of manufacturing a measurement sample in the present embodiment. The method of manufacturing a measurement sample in the present embodiment includes a step S1 of fixing filter paper to a holder for drying, a step S2 of impregnating the filter paper with a liquid containing an object, and a step S3 of drying the filter paper while the filter paper is held by the holder for drying. The "holder for drying" herein includes a first member including a first tubular portion that protrudes like a tube and an annular second member that can fix the filter paper in a flat state under tension by being fitted over the filter paper to surround an outer side of the first tubular portion while the filter paper is carried on the first tubular portion. The "holder for drying" herein may be, for example, holder for drying <NUM> described in the first embodiment.

According to the method of manufacturing a measurement sample in the present embodiment, the filter paper impregnated with a liquid containing an object can be dried in a flat state under tension, and therefore a sample with a flat surface can be obtained. Therefore, highly accurate measurement with Fourier transform infrared spectroscopy can be conducted.

A measurement method in a third embodiment based on the present invention will be described with reference to <FIG> shows a flowchart of the measurement method in the present embodiment. The measurement method in the present embodiment includes a step S1 of fixing filter paper to a holder for drying, a step S2 of impregnating the filter paper with a liquid containing an object, a step S3 of drying the filter paper while the filter paper is held by the holder for drying, and a step S4 of conducting analysis by Fourier transform infrared spectroscopy by irradiating the filter paper with infrared rays while the filter paper is held by the holder for drying after the drying step. The "holder for drying" herein includes a first member including a first tubular portion that protrudes like a tube and an annular second member that can fix the filter paper in a flat state under tension by being fitted over the filter paper to surround an outer side of the first tubular portion while the filter paper is carried on the first tubular portion. The "holder for drying" herein may be, for example, holder for drying <NUM> described in the first embodiment.

According to the measurement method in the present embodiment, after the filter paper impregnated with a liquid containing an object is dried while it is fixed in a flat state, analysis by Fourier transform infrared spectroscopy is conducted, which hence enables highly accurate measurement. Therefore, highly accurate measurement with Fourier transform infrared spectroscopy can be conducted.

As set forth here, not only a sample may be made by drying filter paper <NUM> while it is fixed to holder for drying <NUM> but also analysis by Fourier transform infrared spectroscopy may be conducted by irradiation of filter paper <NUM> with infrared rays while filter paper <NUM> remains fixed to holder for drying <NUM>. Thus, time and efforts for moving a sample to another holder can be saved. Thus, the sample can preferably more reliably be maintained in the flat state.

A ratio of a dimension of the holder for drying shown in <FIG> is merely by way of example, and it is not necessarily as such. The holder for drying does not have to include, for example, projecting portion <NUM>.

Some features in embodiments above may be adopted as being combined as appropriate.

Claim 1:
A holder (<NUM>) for drying a filter paper (<NUM>) comprising:
a first member (<NUM>) including a first tubular portion (<NUM>) that protrudes like a tube; and
an annular second member (<NUM>) that can fix the filter paper (<NUM>) in a flat state under tension by being fitted over the filter paper (<NUM>) to surround an outer side of the first tubular portion (<NUM>) while the filter paper (<NUM>) is carried on the first tubular portion (<NUM>), wherein
the first member (<NUM>) includes an annular projecting portion (<NUM>) around its outer peripheral surface, and the projecting portion (<NUM>) is arranged such that the filter paper (<NUM>) is sandwiched between a lower end (52b) of the second member (<NUM>) being a flat surface and an upper surface (4a) of the projecting portion (<NUM>).