Detail of "139-89-9"

Reference

Aqueous acid descaling solution

Aqueous acid descaling solution. Frenier, Wayne W.; Wilson, David A. (Dow Chemical Co., USA). U.S. US 4430128 A 7 Feb 1984, 5 pp. (English). (United States of America). CODEN: USXXAM. CLASS: IC: C23G001-02. NCL: 134003000. APPLICATION: US 80-213280 5 Dec 1980. DOCUMENT TYPE: Patent CA Section: 55 (Ferrous Metals and Alloys) Hydroxyethylethylenediaminetriacetic acid (I) [150-39-0] in hot aq. solns. at pH <3 is used to remove Fe-rich oxide scale by a chelating mechanism.Several reagents with their cas registry numbers 150-39-0 and 139-89-9 are used here. Typical aq. solns. contain 1-8% I, corrosion inhibitor, and optional mineral acid. Spent I soln. is neutralized with an aq. base, esp. NH4OH, to pH 8-10, oxidized with air or alkali metal nitrite, and used for passivation of ferrous alloy surfaces free from of oxide scale. Thus, I tri-Na salt [139-89-9] was dissolved in water to give 3% I and contacted with 98% H2SO4 to give a pH of 1.2-1.6. A com. amine-based corrosion inhibitor Dowell A175 [88025-95-0] was added at the 0.3% level. Scale removal tests were made on a rusted water pipe section in closed loops at 100°F with 400 mL I soln. pumped at 200 mL/min for 8 h. The pipe was ~90% clean, and the dissolved Fe content in the soln. was 3840-4240 ppm. Control tests with inhibited aq. EDTA at pH 5 showed only 1200 ppm Fe in soln. and resulted in inferior scale removal. .

Automated apparatus for nitrate ion determination

Automated apparatus for nitrate ion determination. (Meidensha Electric Mfg. Co., Ltd., Japan). Jpn. Kokai Tokkyo Koho JP 58066048 A2 20 Apr 1983 Showa, 5 pp. (Japanese). (Japan). CODEN: JKXXAF. CLASS: IC: G01N027-44. APPLICATION: JP 81-164438 15 Oct 1981. DOCUMENT TYPE: Patent CA Section: 79 (Inorganic Analytical Chemistry) Section cross-reference(s): 60, 61 An automated app. is claimed for NO3- detn. employing a polarog. method involving the pre-electrolysis reactions: Cr3+ + e- ? Cr2+ and Cr2+ + Ox ? Cr3+ + Red and the NO3- electroredn. reactions: Cr(III)-hedta + e- ? Cr(II)-hedta and 6 Cr(II)-hedta + NO3- + 8 H+ ? 6 Cr(III)-hedta + NH3OH+ [sic] + 2 H2O [hedta = (NaO2CCH2)2NCH2CH2N(CH2CH2OH)(CH2CO2Na)]. The app. is useful in the detn. 139-89-9 and 7440-47-3 which are cas registry numbers of substances are two of reagents here. of NO3- in aq. media, e.g. river water and sewer water. .