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出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2014/01/07 01:18:22」(JST)

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A fluorometer or fluorimeter is a device used to measure parameters of fluorescence: its intensity and wavelength distribution of emission spectrum after excitation by a certain spectrum of light.^[1] These parameters are used to identify the presence and the amount of specific molecules in a medium. Modern fluorometers are capable of detecting fluorescent molecule concentrations as low as 1 part per trillion.

Fluorescence analysis can be orders of magnitude more sensitive than other techniques. Applications include chemistry/biochemistry, medicine, environmental monitoring. For instance, they are used to measure chlorophyll fluorescence to investigate plant physiology.

Components and Design[edit]

A simplistic design of the components of a fluorometer

Typically fluorometers utilize a double beam. These two beams work in tandem to decrease the noise created from radiant power fluctuations. The upper beam is passed through a filter or monochromator and passes through the sample. The lower beam is passed through an attenuator and adjusted to try and match the fluorescent power given off from the sample. Light from the fluorescence of the sample and the lower, attenuated beam are detected by separate transducers and converted to an electrical signal that is interpreted by a computer system.

Within the machine the transducer that detects fluorescence created from the upper beam is located a distance away from the sample and at a 90-degree angle from the incident, upper beam. The machine is constructed like this to decrease the stray light from the upper beam that may strike the detector. The optimal angle is 90 degrees. There are two different approaches to handling the selection of incident light that gives way to different types fluorometers. If filters are used to select wavelengths of light, the machine is called a fluorometer. While a spectrofluorometer will typically use two monochromators. However, some spectrofluorometers may use one filter and one monochromator, they are still called a spectrofluorometer.

Sources for fluorometers are often dependant on the type of sample being tested. Among the most common source for fluorometers is the low-pressure mercury lamp. This provides many excitation wavelengths, making it the most versatile. However, this lamp is not a continuous source of radiation. The xenon arc lamp is used when a continuous source of radiation is needed. Both of these sources provide a suitable spectrum of ultraviolet light that induces chemiluminescence. These are just two of the many possible light sources.

Glass and silica cells are often the vessels in which the sample is placed. The scientist must be very careful to not leave fingerprints or any other sort of mark on the outside of the cell.

Uses[edit]

Fluorimetry is widely used by the dairy industry to verify pasteurization has been successful. This is done using a reagent which is hydrolysed to a fluorophore and phosphoric acid by alkaline phosphatase in milk.^[2] If pasteurization has been successful then alkaline phosphatase will be entirely denatured and the sample will not fluoresce. This works because pathogens in milk are killed by any heat treatment which denatures alkaline phosphatase.^[3]^[4]

Fluorophos assays are required by milk producers in the UK to prove successful pasteurization has occurred,^[5] so all UK dairies contain fluorimetry equipment.

Fluorometer types[edit]

There are two basic types of fluorometers, the filter fluorometer and the spectrofluorometer. The difference between them is the way they select the wavelengths of incident light. A filter fluorometer will use filters while a spectrofluorometer will use grating monochromators. Filter fluorometers are often purchased/built at a lower cost but are less sensitive and less resolute than spectrofluorometers.

Filter fluorometer
Spectrofluorometer
Handheld fluorometer

References[edit]

^ "Fluorescence Spectrophotometry". Encyclopedia of Life Sciences. Macmillan Publishers Ltd. 2002.
^ Langridge, E W. The Determination of Phosphatase Activity. Quality Management Ltd. Retrieved 2013-12-20.
^ Kay, H. (1935). "Some Results of the Application of a Simple Test for Efficiency of Pasteurisation". The Lancet 225 (5835): 1516–1518. doi:10.1016/S0140-6736(01)12532-8. edit
^ Hoy, W. A.; Neave, F. K. (1937). "The Phosphatase Test for Efficient Pasteurisation". The Lancet 230 (5949): 595. doi:10.1016/S0140-6736(00)83378-4. edit
^ BS EN ISO 11816-1:2013

English Journal

Development of new methods for determining the heparanase enzymatic activity.

Melo CM1, Tersariol IL2, Nader HB3, Pinhal MA4, Lima MA3.
Carbohydrate research.Carbohydr Res.2015 Aug 14;412:66-70. doi: 10.1016/j.carres.2015.04.020. Epub 2015 May 5.
INTRODUCTION: Heparanase is a mammalian endo-β-glucuronidase. Notwithstanding its importance in various pathological and non-pathological events few straightforward methods for heparanase enzymatic activity has been stated. The aim of this study was to develop two heparanase activity assays to cove
PMID 26062789

Sensitive detection of active Shiga toxin using low cost CCD based optical detector.

Rasooly R1, Balsam J2, Hernlem BJ3, Rasooly A4.
Biosensors & bioelectronics.Biosens Bioelectron.2015 Jun 15;68:705-11. doi: 10.1016/j.bios.2015.01.065. Epub 2015 Jan 29.
To reduce the sources and incidence of food-borne illness there is a need to develop affordable, sensitive devices for detection of active toxins, such as Shiga toxin type 2 (Stx2). Currently the widely used methods for measuring Shiga toxin are immunoassay that cannot distinguish between the active
PMID 25677808

Combined effects of graphene oxide and Cd on the photosynthetic capacity and survival of Microcystis aeruginosa.

Tang Y1, Tian J2, Li S2, Xue C2, Xue Z2, Yin D2, Yu S2.
The Science of the total environment.Sci Total Environ.2015 Jun 9;532:154-161. doi: 10.1016/j.scitotenv.2015.05.081. [Epub ahead of print]
In this work, the combined effects of graphene oxide (GO) and Cd2+ solution on Microcystis aeruginosa were investigated. Chlorophyll fluorescence parameters were measured by a pulse-amplitude modulated fluorometer. GO at low concentrations exhibited no significant toxicity. The presence of GO at low
PMID 26070025

Japanese Journal

紫外線発光ダイオードを光源とする可搬型蛍光光度計の開発及びそのCOD推定への応用

鈴木保任,菊田吉弘,山田和広 [他],北出和久,丸田俊久,市田淳一,川久保進
分析化学 63(11), 895-902, 2014
海水や河川水試料の化学的酸素要求量を簡便な方法で推定するため，光源に紫外線発光ダイオード（UV-LED），検出器に光電子増倍管モジュールを使用する可搬型蛍光光度計を開発した．試料水の蛍光強度（励起波長340 nm，蛍光波長450 nm）を測定し，公定法により得られた100℃ における過マンガン酸カリウムによる酸素消費量（CODMn）の値との相関を求めた．試料の採取地点ごとに蛍光強度とCODMnの相 …
NAID 130004712997

Diurnal patterns of the effective quantum yield of the magnificent sea anemone Heteractis magnifica in Pulau Tioman, Malaysia

,
Galaxea, Journal of Coral Reef Studies 15(Supplement), 133-137, 2013
… In this study, the photosynthetic performance in three individuals of Heteractis magnifica was being evaluated using a submersible pulse modulated amplitude fluorometer (Diving PAM). …
NAID 130004953712

Intracellular calcium ion concentrations in endothelial cells in preeclampsia

, , , , ,
Hypertension Research in Pregnancy 1(2), 93-97, 2013
… [Ca2+]i values were measured in ECs treated with sera from 29 normal pregnant women, 7 PE patients, and 10 non-pregnant women by monitoring fluorescence using a CAM 220 fluorometer.Results: [Ca2+]i values were significantly higher in ECs treated with sera from normal pregnant women compared to those from non-pregnant women, and the effects were even stronger when ECs were treated with sera from pregnant women who were in later stages of pregnancy. …
NAID 130004638244