Anions from Disinfection

An electrospray ion source enlarges the range of analytes accessible to IMS, field asymmetric IMS (FAIMS), or DMS measurements, and ESI-FAIMS-MS was used in the determination of aqueous-based haloacetic acids, a class of disinfection by-products regulated by the U.S. EPA. The method of ESI-FAIMS effectively discriminated against background ions resulting from the electrospray of tap water solutions containing the haloacetic acids, and this simplified mass spectral response. The selectivity of ESI-MS was improved, and the limits of detection were lowered for six 

Anions have also been determined using conventional IMS with an FSI ion source and included arsenate, phosphate, sulfate, nitrate, nitrite, chloride, formate, and acetate. Distinct peak patterns and reduced mobility constants were observed for respective anions. Application to authentic water samples for the determination of nitrate and nitrite demonstrated the feasibility of using FSI-IMS as a rapid analytical method for monitoring nitrate and nitrite in water systems. The method was used for on-site measurement by exchanging air for nitrogen as the drift gas without complications. The linear dynamic range was 1,000, and detection limits were 10 ppb for nitrate and 40 ppb for nitrite. 

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There are two reasons why the concentration of quaternaries is beheved to remain at a low level in sewage treatment systems. First, quaternaries appear to bind anionic compounds and thus are effectively removed from wastewater by producing stable, lower toxicity compounds (205). Anionic compounds are present in sewer systems at significantly higher concentrations than are cations (202). Second, the nature of how most quaternaries are used ensures that their concentrations in wastewater treatment systems are always relatively low but steady. Consumer products such as fabric softeners, hair conditioners, and disinfectants contain only a small amount of quaternary compounds. This material is then diluted with large volumes of water during use. 

Wu Q, Zhang T, Sun H, Kannan K (2010) Perchlorate in drinking water, groundwater, surface waters and bottled water from China, and its association with other inorganic anions and with disinfection byproducts. Arch Environ Contam Toxicol 58 543-550... 

It is widely employed as a disinfectant in medicine (Povidone-iodine) because of its mildness, low toxicity, and water solubility. According to the U.S. Pharmacopeia, l ovidone-iodme is a free-flowing, brown powder dial contains from 9-12% available iodine. 11 is soluble in water and lower alcohols. When dissolved in water, the uncomplexed free iodine level is very low however, tine complexed iodine acts as a reservoir and by equilibrium replenishes the free iodine lo the equilibrium level. This prevents free iodine from being deactivated because the free form is continually available at effective biocidal levels from this large reservoir. PVP will interact with other small anions and resembles serum albumin and other proteins in this regard. It can be salted in with anions such as NaSC.N or out with NasSOa much like water-soluble proteins. 

In the early part of2004 there was a problem in the UK caused by low levels ofbromate in a branded bottled water. This arose from the presence of low levels of bromide in the water that was then disinfected by treatment with ozone. The bromate ions formed were at levels above the EU and EPA limit of lOpg/l for drinking water. The analysis of this anion at trace levels is demanding and should be left to a specialist laboratory. However, Dionex have published four methods that can be used for the analysis of bromate ions in water and the application notes (81, 101, 136 149) are available from the Dionex website (http /www. dionex. com/)... 

Ion exchangers can be used for removal of Fe " and Mn " " ions from water, as weU as for removal of fluorides, ammonia and oxygen. For water disinfection, silver-impregnated anion exchangers with sterilizing effects can be used. For water dechlorination, resistant cation exchangers in the NH3 form are recommended. Trials of ion exchangers for removal of phenols from water have also been carried out. 

Isopropyl alcohol is widely used as a solvent, an antiseptic, and a disinfectant and is commonly available in the home as a 70% solution (rubbing alcohol). It Is often ingested by alcoholics as a cheap substitute for liquor. Unlike the other common alcohol substitutes methanol and ethylene glycol, isopropyl alcohol is not metabolized to highly toxic organic acids and therefore does not produce a profound anion gap acidosis. Hospitals sometimes color isopropyl alcohol with blue dye to distinguish it from other clear liquids this has led abusers to refer to it as blue heaven. ... 

Treated waters for domestic use are routinely analyzed using IC for both naturally present common inorganic anions and trace anionic contaminants, several classes of which actually originate as by-products of the treatment processes themselves. Oxyhalides, which originate from various drinking water disinfection processes, such as chlorination and ozonation, can be found present in finished drinking... 

The past two decades have seen the establishment of a very extensive literature on the application of boron-doped diamond electrodes for the decoloration and the removal of COD and TOC from effluents, the disinfection and quality improvement of water, and the complete oxidation of particular organic molecules [26, 38, 39, 71-75]. There can be no doubt that boron-doped diamond anodes allow the effective killing of microorganisms and the complete oxidation of a wide range of organic compounds to carbon dioxide (and other inorganic fragments). Both direct and indirect mechanisms have been invoked. The direct mechanisms involve electron transfer and oxidation via weakly adsorbed OH radicals, while the indirect mechanisms have seen a role for solution-free OH radicals, ozone, sulfate radicals, or chlorine compounds if suitable anions are present or added. Indirect routes via ozone [20, 21] and sulfate radicals [40, 74, 76-78] can, of course, become dominant with appropriate selection of the conditions. This literature has been extensively reviewed and the interested reader is referred to these reviews [26, 38, 39, 71-75]. 

The latest postcolumn derivatization method for the analysis of disinfection by-product anions such as bromate and chlorite has been published as Method 326.0 by the US EPA [68,69]. This method was developed as an alternative to Method 317.0, because o-dianisidine has been identified as a potential human carcinogen [70]. Method 326.0 uses a postcolumn reaction that generates hydro-iodic acid (HI) in situ, from an excess of potassium iodide that combines with bromate from the column effluent to form the tri-iodide anion, I3. The reaction product can then be detected photometrically at 352 nm. Most published EPA... 

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