関: mEq

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one-thousandth of an equivalent (同)meq

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出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2014/07/16 16:10:00」(JST)

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The equivalent (symbol: eq ), sometimes termed the molar equivalent, is a unit of electrical charge used in chemistry and the biological sciences. It could be converted to Coulombs 'C' (SI unit) using Faraday's constant F in 'C/mol', where 1 'eq' = F 'C'.

The equivalent of substance A is the amount of substance A multiplied by its valence.

The equivalent could be also formally defined through the amount of substance which will either:

react with or supply one mole of hydrogen ions (H⁺) in an acid–base reaction; or
react with or supply one mole of electrons in a redox reaction.^[1]^[2]

The mass of one equivalent of a substance is called its equivalent weight.

A historical definition, used especially for the chemical elements, describes an equivalent as the amount of a substance that will react with one gram of hydrogen, or with eight grams of oxygen, or with 35.5 grams (1.25 oz) of chlorine, or displaces any of the three.^[3]

In practice, the amount of a substance in equivalents often has a very small magnitude, so it is frequently described in terms of milliequivalents (mEq or meq), the prefix milli denoting that the measure is divided by 1000. Very often, the measure is used in terms of milliequivalents of solute per litre of solvent (or milliNormal, where mEq/L = mN). This is especially common for measurement of compounds in biological fluids; for instance, the healthy level of potassium in the blood of a human is defined between 3.5 and 5.0 mEq/L.

A certain amount of univalent ions provides the same amount of equivalents while the same amount of divalent ions provides twice the amount of equivalents. For example, 1 mmol of Na⁺ is equal 1 mEq, while 1 mmol of Ca⁺⁺ is equal 2 mEqs.

References

^ IUPAC, Compendium of Chemical Terminology, 2nd ed. (the "Gold Book") (1997). Online corrected version: (2006–) "equivalent entity".
^ International Union of Pure and Applied Chemistry (1998). Compendium of Analytical Nomenclature (definitive rules 1997, 3rd. ed.). Oxford: Blackwell Science. ISBN 0-86542-6155. section 6.3.
^ "Atome", Grand dictionnaire universel du XIXe siècle 1, Paris: Pierre Larousse, 1866, pp. 868–73 . (French)

External links

A dictionary of units of measurement

English Journal

Prediction of drinking water intake by dairy cows.

Appuhamy JA1, Judy JV2, Kebreab E3, Kononoff PJ2.
Journal of dairy science.J Dairy Sci.2016 Sep;99(9):7191-205. doi: 10.3168/jds.2016-10950. Epub 2016 Jun 16.
PMID 27320675

Effect of chitosan on shelf life of restructured fish products from pangasius (pangasianodon hypophthalmus) surimi during chilled storage.

Jeyakumari A1, George Ninan2, Joshy C G2, Parvathy U1, Zynudheen A A2, Lalitha K V2.
Journal of food science and technology.J Food Sci Technol.2016 Apr;53(4):2099-107. doi: 10.1007/s13197-016-2174-3. Epub 2016 Apr 20.
PMID 27413240

Effect of dietary cation-anion difference on ruminal metabolism, total apparent digestibility, blood and renal acid-base regulation in lactating dairy cows.

Martins CM1, Arcari MA1, Welter KC2, Gonçalves JL1, Santos MV1.
Animal : an international journal of animal bioscience.Animal.2016 Jan;10(1):64-74. doi: 10.1017/S1751731115001548. Epub 2015 Aug 20.
PMID 26289745

Japanese Journal

Preparation and Evaluation of Eudragit Gels. V. Rectal Gel Preparations for Sustained Release and Avoidance of First-Pass Metabolism of Lidocaine

金洛瑞,梅島啓之,伊藤隆弘,内田享弘,後藤茂
Chemical & pharmaceutical bulletin 40(10), 2800-2804, 1992-10-25
… The release rate of lidocaine from hydrogel and xerogel increased with the increase in the amount of sodium hydroxide incorporated within the range of 3 to 7 milliequivalent (meq). …
NAID 110003654919

Preparation and evaluation of rectal gel preparations for controlled release of pentoxifylline used as new hemorrheologic agent in cerebrovascular diseases.

金洛瑞,川田昌和,後藤茂
Ｄｒｕｇ　Ｄｅｌｉｖｅｒｙ　Ｓｙｓｔｅｍ 5(4), 231-236, 1990
… release rate of pentoxifylline from hydrogels was much the same as that found for Witepsol S-55 suppository and could he controlled by modifying the milliequivalent (mEq) of NaOH per unit weight of the polymer materials and the percentages of the polymer materials added to the hydrogels. …
NAID 130000747536

飼料作物栽培に関する沖縄土壌の施肥管理 : II. 暗赤色土におけるローズグラスのカリ施用に対する反応(農芸化学科)

大屋一弘,石嶺行男,宮城盛時,前当正範
琉球大学農学部学術報告 35, 17-26, 1988-12-05
本研究は暗赤色土(通称島尻マージ)におけるカリ施用に対するローズグラス(Chloris gayana Kunth, Culti. var. ELMBA)の反応, カリ施用に伴うローズグラスのカリ, カルシウム, マグネシウムの吸収及び土壌肥沃度に及ぼすローズグラス栽培の影響などを圃場条件下で調べることを目的とした。ローズグラスは農学部附属農場No.17圃場(暗赤色土)で栽培されているものを用いたが …
NAID 110000219717