Standard Methods for the Examination of Water and Wastewater Practice Flashcards

Comprehensive vocabulary flashcards covering Standard Methods for Inorganic Nonmetallic Constituents including analytical techniques like Ion Chromatography, SFA, FIA, CIE, and specific tests for Boron, Cyanide, and Chlorine.

Ion Chromatography

A single instrumental technique used for the rapid, sequential measurement of common anions such as $Br^-$, $Cl^-$, and $F^-$ by distinguishing between halides and oxy-ions using ion exchangers.

Chemical Suppression

A process in ion chromatography where a suppressor converts separated anions into highly conductive acid forms and transforms the carbonate-bicarbonate eluent into weakly conductive carbonic acid.

Water Dip

A negative contribution corresponding to the elution of water in ion chromatography, which makes fluoride ($F^-$) difficult to quantitate at low concentrations.

Segmented Flow Analysis (SFA)

An automated wet chemical analysis method described as a 'conveyor belt' system where reagents are added in a 'production-line' manner and liquid segments are separated by air bubbles.

Longitudinal Dispersion

A carryover process in segmented flow analysis that occurs as a result of laminar flow; it is minimized by the use of air bubble segmentation.

Flow Injection Analysis (FIA)

An automated method of introducing a precisely measured portion of liquid sample into a continuously flowing carrier stream, forming an asymmetric Gaussian gradient in analyte concentration.

Capillary Ion Electrophoresis (CIE)

An instrumental technique where anions are separated in a 75-μm-ID silica capillary based on differences in their mobility within an electric field.

Electroosmotic Flow Modifier (OFM)

A substance, such as tetradecyltrimethyl ammonium bromide ($TTAB$), used in capillary ion electrophoresis to fill the silica capillary and modify flow characteristics.

Indirect UV Detection

A detection method where anions are identified as they displace a UV-absorbing electrolyte anion like chromate, causing a net decrease in UV absorbance.

Borism

A clinical syndrome resulting from the protracted ingestion of large amounts of boron, which can affect the central nervous system.

Curcumin Method

An analytical procedure for boron where an acidified sample is evaporated in the presence of curcumin to form a red-colored product called rosocyanine.

Carmine Method

A method for boron determination in the $1$ to $10\,mg/L$ range where carmine or carminic acid in concentrated sulfuric acid ($H_2SO_4$) changes from bright red to bluish red or blue.

Simple Cyanides

Cyanide compounds represented by the formula $A(CN)_x$, where A is an alkali or a metal and the $CN$ group is present as $CN^-$ or molecular $HCN$.

Complex Cyanides

Alkali-metallic cyanides typically represented by $A_yM(CN)_x$, where $M$ is a heavy metal such as iron, cadmium, copper, or nickel.

Cyanogen Chloride ($CNCl$)

A highly toxic gas formed as the first reaction product during the chlorination of cyanide compounds; it later hydrolyzes to the cyanate ion ($CNO^-$).

Cyanide Amenable to Chlorination

Form of cyanide determined by the difference in total cyanide between an unchlorinated sample and one that has been chlorinated to destroy dissociable forms.

Weak Acid Dissociable (WAD) Cyanide

Cyanide species liberated from a slightly acidified sample ($pH\,4.5$ to $6.0$) under prescribed distillation conditions, excluding tight complexes like those of iron.

Free Chlorine

Aqueous chlorine existing as molecular chlorine, hypochlorous acid ($HOCl$), and hypochlorite ion ($OCl^-$) in pH- and temperature-dependent proportions.

Combined Chlorine

Chlorine forms such as monochloramine, dichloramine, and nitrogen trichloride that result from the reaction of free chlorine with ammonia or nitrogenous compounds.

Amperometric Titration

A standard method of comparison for free or combined chlorine that uses the polarographic principle and a noble-metal electrode to detect the titration end point.

DPD Method

Specifically the N,N-diethyl-p-phenylenediamine method, which uses ferrous ammonium sulfate ($FAS$) and DPD indicator to differentiate chlorine species.

Phenylarsine Oxide ($PAO$)

A standard reducing reagent used in chlorine titrations; it is characterized as a severe poison and a suspected carcinogen.