Reference

Haloacetonitrile excretion as thiocyanate and inhibition of dimethylnitrosamine demethylase: a proposed metabolic scheme

Haloacetonitrile excretion as thiocyanate and inhibition of dimethylnitrosamine demethylase: a proposed metabolic scheme. Pereira, Michael A.; Lin, Luan Ho C.; Mattox, Joan K. (Health Effects Res. Lab., U.S. Environ. Prot. Agency, Cincinnati, OH 45268, USA). J. Toxicol. Environ. Health, 13(4-6), 633-41 (English) 1984. CODEN: JTEHD6. ISSN: 0098-4108. DOCUMENT TYPE: Journal CA Section: 4 (Toxicology) Haloacetonitriles, contaminants present in chlorinated drinking water, were administered orally to rats, and the urinary excretion of thiocyanate was measured as an index of CN release. The urinary excretion of thiocyanate accounted for 14.2% of the dose of monochloroacetonitrile [107-14-2]; 7.7-12.8% of the dose of bromochloro- [83463-62-1], dichloro- [3018-12-0], and dibromoacetonitrile [3252-43-5]; and 2.25% of the dose of trichloroacetonitrile [545-06-2]. The haloacetonitriles inhibited rat liver microsomal dimethylnitrosamine demethylase (I) [9075-31-4] in an in vitro assay system. Dibromo- and bromochloroacetonitrile were the most potent inhibitors of I, with Ki = 3-4 ′ 10-5M; dichloro- and trichloroacetonitrile were the next most potent, with Ki = 2 ′ 10-4M; and monchloroacetonitrile was the least potent inhibitor, with Ki = 9 ′ 10-2M. Trichloroacetonitrile, but not dibromoacetonitrile, when administered orally inhibited hepatic I activity. The relative capacity of the haloacetonitriles to inhibit I and to be excreted as thiocyanate did not correlate.

The removal of organic halide precursors by preozonation and alum coagulation

The removal of organic halide precursors by preozonation and alum coagulation. Reckhow, David A.; Singer, Philip C. (Dep. Environ. Sci. Eng., Univ. North Carolina, Chapel Hill, NC 27514, USA). J. - Am. Water Works Assoc., 76(4), 151-7 (English) 1984. CODEN: JAWWA5. ISSN: 0003-150X. DOCUMENT TYPE: Journal CA Section: 61 (Water) Alum coagulation of an aquatic fulvic acid soln. removed all org. halide precursors tested (i.e., of trihalomethanes (THM's), total org. halides (TOH's), trichloroacetic acid (I) [76-03-9], dichloroacetic acid (II) [79-43-6], dichloroacetonitrile (III) [3018-12-0], and 1,1,1-trichloroacetone (IV) [918-00-3]) to a significant extent. The percentage removals showed the same trends as, but were not identical to, those for total org. C (TOC) and UV absorbance. TOC was removed to a lesser extent than all but IV precursors. UV absorbance was removed to a greater extent than all precursors. Ozonization at pH 7 with typical O3 dosages at typical HCO3- levels removed THM's, TOH's, I, and III precursors, but did not change II and increased IV precursors. UV absorbance was destroyed to a greater extent during preozonization than THM, TOH, or I precursors. Ozonization with 0.3 and 1.2 mg O3/mg C at natural HCO3- levels and pH 7 hindered coagulation of org. precursors, TOC, and UV-absorbing substances, thereby decreasing overall removal of halide precursors from both the fulvic acid soln. and a moderately colored raw drinking water.