The recoveries of 16 isomers of chlorophenols (CPs) from the adsorbent (XAD-2) of the MM5 train are affected by hydrochloric acid (HCl) present in the incinerator flue gas. At 2.05 and 5.53 mg/L in flue gas, HCl caused desorption of CPs from XAD-2. The desorption is dependent upon the number of chloro substituents in the CPs. The Soxhlet extraction behaviors of CPs from XAD-2 in the presence or the absence of HCl were also studied in the laboratory. The results explain the previously reported low recovery of pentachlorophenol from XAD-2 when the flue gas contained none or very low concentrations of HCl. An extraction procedure for complete CPs recoveries from XAD-2 is proposed that involved two sequential extractions:  first with dichloromethane and then with the addition of 1.0 mL of 1.0 M aqueous HCl on XAD-2 and followed by the subsquent extraction with dichloromethane. This procedure does not affect other semivolatile compounds on XAD-2 and leads to [13C6]pentachlorophenol surrogate recovery of 90 ± 6%. An extraction anomaly of CPs using dichloromethane from the combined synthetic acidic condensate and acidic ethylene glycol is presented. Toluene is suggested as the solvent for complete CPs extraction from the combined liquids. This acid effect led to a suggestion of using at least one surrogate isomer for each CP group on XAD-2 of the MM5 train.

1,2-Benzdiyne equivalents possess the unique property that they can react with two arynophiles through iteratively generated 1,2- and 2,3-aryne intermediates. Upon rational modification on the second leaving group of these aryne precursors, a domino aryne annulation approach was developed through a nucleophilic-ene reaction sequence. Various benzo-fused N-heterocyclic frameworks were achievable under transition metal-free conditions with a broad substrate scope.

The effect of hydrochloric acid (HCl) at 0.17, 2.05, and 5.53 mg/L in incineration flue gas on the recoveries of 16 polycyclic aromatic hydrocarbons (PAHs) from XAD-2 adsorbent of the MM5 (Modified Method 5) train was investigated. At constant concentrations of moisture (14%), carbon dioxide (7%), and oxygen (10%), 2.05 and 5.53 mg/L HCl decreased the recoveries of benzo[a]pyrene, perylene, anthracene, and acenaphthylene. At 5.53 mg/L HCl, only 6, 8, 32, and 46% of these PAHs, respectively, were recovered from XAD-2. The recoveries of other PAHs were 88-112% with relative standard deviations of 3-13% at all acid concentrations in flue gas. Acid effect occurred primarily during sampling of flue gas, and a smaller acid effect occurred during sample processing, in which the XAD-2 containing HCl, PAHs, and moisture was Soxhlet extracted using dichloromethane. The hypothesis is that these PAHs formed cation radicals in the presence of HCl, which was followed by subsequent reaction with water to yield quinones. The extraction of PAHs from synthetic acidic condensate and acidic ethylene glycol of the MM5 train was not dependent on pH. Extractions from various acidities of these combined solutions gave recoveries of 76-102% with relative standard deviations of 4-13%. The implications of all the above-mentioned effects on the selection of surrogates and interpretation of analytical results for MM5 sampling and analysis are discussed.

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An analytical method has been developed to determine arsenlc(V) In ferric chloride-hydrochloric acid leaching media using Ion chromatography with conductivity detection. Oxidation of As(III) by aqua regia allows arsenlc(III) to be determined by difference. The method Involves a preseparation of trace quantities of arsenic from the relatively large concentrations of ferric chloride and hydrochloric acid prior to the Ion chromatography measurement. Iron(III) Is separated by passing the sample through a hydrogen-form cation exchange column, and arsenlc(III) and arsenlc(V) are then eluted with water. The effect of the concentration of acid In this separation Is discussed. The effluent collected from the cation exchange column Is evaporated to remove the hydrochloric acid. The accuracy and precision of the method were determined from the analysis of various synthetic solutions and are discussed; an accuracy of ±4% was obtained even at arsenlc(V) concentrations as low as 10 ppm. The extent of oxidation of arsenic(III) In acidic ferric chloride solution and the reduction of arsenic(V) In acidic ferrous chloride solution were measured. The results obtained by Ion chromatography are compared to the values realized using colorimetry after the preseparation step.