| 释义 |
reagent|riːˈeɪdʒənt|
[re- 2 a; cf. react v.1]
1. Chem. Orig., a substance employed as a test to determine the presence of some other substance by means of the reaction which is produced. Now, any substance employed in chemical reactions (cf. sense 2).
1797Hatchett in Phil. Trans. LXXXVIII. 115 The liquor..being examined by the re-agents commonly used, afforded no trace of matter in solution. 1812Sir H. Davy Chem. Philos. 27 Boyle..introduced the use of tests or reagents, active substances for detecting the presence of other bodies. 1880Darwin in Life & Lett. (1887) III. 346 Injecting various reagents into the tissues of leaves. 1904L. W. Riggs Elem. Man. Chem. Laboratory iii. 82 Any positive ion..when separated from other cations..will exhibit with reagents certain phenomena characteristic of that ion. 1929C. R. Hayward Dict. Metall. Pract. xxii. 487 Recarburizing..may be accomplished by adding the reagents to the converter. 1948Currier & Rose Gen. & Appl. Chem. xix. 151 Nitric acid..is a very important substance: in the laboratory as an oxidizing reagent, and in industry for the manufacture of explosives. 1964N. G. Clark Mod. Org. Chem. v. 65 Traditional reagents and reaction conditions rarely affect the paraffins, but they exhibit useful reactivity at high temperatures. 1973Materials & Technol. VI. viii. 545 To make a bonded joint, the PTFE is first etched with a reagent.
2. A reactive substance, force, etc. (Sometimes directly transf. from prec.)
1856Emerson Eng. Traits, Race 27 Civilization is a re⁓agent, and eats away the old traits. 1865M. Pattison Serm. 109 Mind is a reagent against society. 1880W. MacCormac Antis. Surgery 113 The antiseptic method is not the mere employment of any single reagent.
3. Comb. reagent grade, a grade of commercial chemicals characterized by a high standard of purity; freq. attrib.; reagent paper, paper treated with a reagent for use in chemical tests.
1935Jrnl. Amer. Chem. Soc. LVII. 408/2 Baker and Adamson CuSO4.5H2O, Reagent Grade, was recrystallized twice from distilled water. 1945Ibid. LXVII. 1096/1 Reagent grade ammonium sulfate was heated at 75° for several days. 1966A. S. Prasad Zinc Metabolism xv. 275 Six of..[the patients] received reagent grade zinc sulfate 90 mg daily, and three received reagent grade ferrous sulfate 1 gm orally daily. 1973Jrnl. Amer. Chem. Soc. XCV. 1913/1 All reagents and solvents used were reagent grade and, unless noted otherwise, were used without further purification.
1908Practitioner Mar. 410 A pea-sized piece being rubbed up with 2 c.c. of water, and the reagent-paper dipped into this. |