CN Concentration Research Articles

Priority pollutants and associated constituents in untreated and treated discharges from coal mining or processing facilities in Pennsylvania, USA

Clean sampling and analysis procedures were used to quantify more than 70 inorganic constituents, including 35 potentially toxic or hazardous constituents, organic carbon, and other characteristics of untreated (influent) and treated (effluent) coal-mine discharges (CMD) at 38 permitted coal-mining or coal-processing facilities in the bituminous coalfield and 4 facilities in the anthracite coalfield of Pennsylvania. Of the 42 facilities sampled during 2011, 26 were surface mines, 11 were underground mines, and 5 were coal refuse disposal operations. Treatment of CMD with caustic soda (NaOH), lime (CaO or Ca(OH)2), flocculent, or limestone was ongoing at 21%, 40%, 6%, and 4% of the facilities, respectively; no chemicals were added at the remaining facilities. All facilities with CMD treatment incorporated structures for active or passive aeration and settling of metal-rich precipitate.The untreated influent samples had wide ranges of pH (2.8–7.6), hot acidity (−600 to 8000mg/L as CaCO3), specific conductance (SC; 253–13,000μS/cm), total dissolved solids (TDS; 168–18,100mg/L), and associated dissolved (<0.45-μm pore-size filter) constituents, including SO4 (14.7–10,700mg/L), Fe (<0.01 to 4100mg/L), Mn (0.02–136mg/L), Al (<0.01 to 128mg/L), and Zn (<0.003 to 18.8mg/L). Concentrations of Ag (<1μg/L), Hg (<1μg/L), Sn (<0.5μg/L), and CN (<0.01mg/L) were below detection limits. Only one influent sample met permitted mine effluent (PME) limits plus dissolved-constituent criteria maximum concentration (CMC) thresholds for the protection of freshwater aquatic organisms.The pH of the treated effluent samples ranged from 5.5 to 11.9 and was greater than or equal to the pH of the corresponding influent at all sites. All the effluent samples met CMC levels for dissolved concentrations of Ag, As, Ba, Cd, Cl, Cr, Pb, Ni, Sb, Se, Tl, V, NH3, NO2, NO3, and CN; however, nine violated one or more of the PME limits for pH (<6, n=1), net acidity (>0, n=3), Fe (>7mg/L, n=1), or Mn (>5mg/L, n=8), plus one or more exceeded CMC levels for Al (>0.75mg/L, n=2), Co (>95μg/L, n=5), Zn (>307μg/L, n=1), Cu (>7.4μg/L, n=1), or Se (>12.8μg/L, n=3). Although CMC exceedances for Co and Zn were attributed to samples also violating the PME limit for pH or Mn, the samples that exceeded the CMC for Al, Cu, or Se met applicable PME limits for pH, Fe, and Mn. Furthermore, many of the pH-compliant effluents did not meet reference criteria for SO4 and related measures of ionic strength, including TDS, SC, and osmotic pressure.The Wilcoxon matched-pair signed-ranks statistic was used to test if the overall difference between the effluent and influent pairs was equal to zero. Constituents that statistically were the same for effluent and influent (p>0.05) included flow rate, SC, osmotic pressure, hardness, alkalinity, total organic carbon (TOC), K, Cl, NO3, PO4, Sb, Sr, Br, Se, Mo, and V. Although temperature, dissolved oxygen, pH, Ca, and Na were greater in the effluent than the influent, most constituents decreased as a result of treatment, including TDS, acidity, SO4, Al, Fe, Mn, Mg, As, Ba, Be, Cd, Cr, Co, Cu, F, Pb, Ni, NH3, Tl, Ti, U, Zn, Zr, total phenols, total inorganic carbon (TIC), biological oxygen demand (BOD), and chemical oxygen demand (COD). Nevertheless, some constituents that decreased, such as SO4, still did not meet reference criteria.Findings from this study suggest that typical chemical or aerobic treatment of CMD to pH>6 with removal of Fe to <7mg/L and Mn to <5mg/L may provide a reasonable measure of protection for aquatic life from priority pollutant metals and other toxic or hazardous constituents in effluent but may not be effective for achieving permissible or background levels for TDS, SC, osmotic pressure, or concentrations of SO4 and some other pollutants, including Se, Br, and Cl, if present.

Highly selective and sensitive nanoprobes for cyanide based on gold nanoclusters with red fluorescence emission.

We report a novel and environmentally friendly fluorescent probe for detecting the cyanide ion (CN(-)) using L-amino acid oxidase (LAAOx)-protected Au nanoclusters (LAAOx@AuNCs) with red emission. The fluorescence-based sensing behaviour of LAAOx@AuNCs towards anions was investigated in buffered aqueous media. Among the anions studied, CN(-) was found to effectively quench the fluorescence emission of AuNCs based on CN(-) induced Au core decomposition. Excellent sensitivity and selectivity toward the detection of CN(-) in aqueous solution were observed. The CN(-) detection limit was determined to be approximately 180 nM, which is 15 times lower than the maximum level (2700 nM) of CN(-) in drinking water permitted by the World Health Organization (WHO). A linear relationship between the fluorescence intensity and CN(-) concentration was observed in two ranges of CN(-) concentration, including 3.2 × 10(-6) to 3.4 × 10(-5) mol L(-1) and 3.81 × 10(-5) to 1.04 × 10(-4) mol L(-1). The high sensitivity and selectivity to CN(-) among the 17 types of anions make the AuNCs good candidates for use in fluorescent nanoprobes of CN(-).

Preparation and optical properties of highly luminescent colloidal single-layer carbon nitride

Thermal treatment of graphitic carbon nitride (g-CN) in aqueous solutions of tetraethyl ammonium hydroxide at ∼100 °C yields colloidal solutions retaining stability at a CN concentration of up to 50 g L−1 and upon dilution by a factor of 103.

Aircraft measurements of the vertical distribution and activation property of aerosol particles over the Loess Plateau in China

For the first time, comprehensive aircraft measurements of atmospheric aerosols and cloud condensation nuclei (CCN) were made over the Loess Plateau in Shanxi, China. Data from six flights in July and August 2013 were analyzed. Fine aerosols were predominant over the region. On the one hazy day, the fraction of fine particles in the total aerosol load was the greatest. Aerosol number concentration decreased exponentially with altitude. Inversion layers caused low-level aerosol accumulation zones. The mean aerosol particle size increased with altitude, and the larger particles were mainly found above 2km. Aerosol number size distributions at different height ranges showed two or three peaks. The aerosol number size distribution from 0.01μm to 20μm can be fitted with three log-normal distribution functions. The number concentration of CCN (NCCN) decreased with altitude. NCCN was linearly related to the CN concentration (NCN). The fraction of CCN to CN (fCCN/CN) at 0.3% SS was half of that at 0.4% SS. The fCCN/CN on the hazy day was lower than on the clear days. Vertical profiles of fCCN/CN and the effective diameter (ED) were similar, although the fCCN/CN increased with altitude.

Electrofluorochromic detection of cyanide anions using a nanoporous polymer electrode and the detection mechanism.

An electrofluorochromic (EFC) conjugated copolymer (PEFC) containing carbazole and benzothiadiazole (BTD) moieties is synthesized through Suzuki coupling followed by electrochemical polymerization, resulting in a nanoporous EFC polymer electrode. The electrode exhibits high sensitivity and selectivity in the EFC detection of cyanide anions (CN(-)) in largely aqueous electrolyte (67 vol % water) because electrochemical oxidation of PEFC leads to significant fluorescence quenching, and the presence of different concentrations (1 to 100 μM) of CN(-) in the electrolyte can weaken the oxidative quenching to substantially different extents. Although PEFC is hydrophobic in the neutral state, it is converted to radical cation/dication states upon oxidation, rendering the PEFC some hydrophilicity. Moreover, its nanoporous morphology provides a large surface area and short diffusion distance, facilitating the movement of CN(-) in the electrolyte into the PEFC film to interact with receptors. Density functional theory calculations show that the noncovalent interaction between electron-deficient BTD and nucleophilic CN(-) is energy favorable in the oxidized states in both aqueous and organic media, suggesting that the specific π(-)-π(+) interaction plays the main role in the CN(-) detection.

Development and application of CN PLIF for single-shot imaging in turbulent flames

A laser-induced fluorescence concept for improved interference-free imaging detection of the cyano radical (CN), an intermediate species in nitrogen combustion chemistry, has been investigated. Both a standard Nd:YAG-pumped dye laser and a solid-state alexandrite laser were employed for excitation of CN B–X (1–0) lines near 359nm in combination with detection of the (1–1) band near 387nm, providing a direct comparison of interferences and achievable detection sensitivity. Measurements in ammonia-doped premixed methane–air flames showed that the alexandrite laser, with longer pulse duration (∼30ns) and broader line width (2.5cm−1), can provide around 4 times stronger CN signal than that achievable with conventional Nd:YAG pumped dye laser system. Enhanced CN detection using alexandrite laser excitation is demonstrated that signal-to-noise ratio ∼5 is achieved for single-shot fluorescence imaging at conditions with CN concentration levels experimentally estimated to be a few hundred ppbs. This improved detection sensitivity, however, might still not be sufficient for pure methane/air flames due to low CN concentration. Observations of local extinction, represented by CN layer dis-continuation, in turbulent flames suggest that the improved CN detection will be useful for deepened understanding of interactions between fuel-nitrogen chemistry and local turbulent transport in combustion.

Primary and secondary aerosols from an urban site (Kanpur) in the Indo-Gangetic Plain: Impact on CCN, CN concentrations and optical properties

The number concentrations of cloud condensation nuclei (CCN) and submicron aerosols (CN), along with their chemical composition and optical properties, have been studied during October 2008, October–November 2009 and November 2010 from an urban (Kanpur) site in the Indo-Gangetic Plain (IGP). The concentrations of CCN and CN and their optical properties vary with primary emission and secondary aerosol formation. The CCN (at 0.38% super-saturation) and CN concentrations varied from ∼3900 to 15,000 cm−3 and ∼23,000 to 99,000 cm−3, respectively. The diurnal variability of CCN and CN show peak concentrations during early morning hours (6:00–9:00 AM) and nighttime (7:00–10:00 PM), attributable to variability in source strength of carbonaceous aerosols and secondary aerosol formation. The CCN and CN concentrations are ∼50% higher during nighttime with simultaneous increase in organic carbon (OC), elemental carbon (EC) and NO3– mass concentrations. However, CCN/CN ratios are similar during day and nighttime suggesting their co-variability with primary and secondary aerosol formation. The CCN/CN ratios are relatively lower (range: 0.11–0.33) than global average value and those over urban areas (with similar chemical composition in China and around the world) suggesting suppressed activation and hygroscopic growth in highly polluted environment of the IGP. The average mass absorption efficiency of EC during daytime (11.7 ± 2.5 m2 g−1) is about factor of two higher than that during nighttime (5.7 ± 1.3 m2 g−1). These results have implications to study morphological features, mixing state and microphysical properties of aerosols under high acidic environment over northern India.

CCN closure results from Indian Continental Tropical Convergence Zone (CTCZ) aircraft experiment

In-situ aircraft measurements of cloud condensation nuclei (CCN) and aerosol size distribution were carried out over the region spanning from 24.78 °N to 29.5 °N and 78.1 °E to 85.0 °E from June 29 to July 3, 2009 during the Indian Continental Tropical Convergence Zone (CTCZ) campaign, consisting of total 9 flight sorties. CCN measurements were conducted at a constant supersaturation (SS) of 0.84%. It was found that at higher altitudes (4.7–6.7km), 30nm sized particles were dominating while at lower altitudes (0.6–3.7km), 50nm particles. Overall, CCN closure ratio (CCNpredicted/CCNmeasured) at different altitudes using Köhler theory and assuming pure ammonium sulfate was 1.375 (R2=0.80). For each sortie, the closure ratio varied with height and depended greatly on measured CN concentrations. A case study of Khajuraho sortie showed that the closure ratio increased from 1.07 to 1.40 as the CCN concentration increased from 1000cm−3 to 4000cm−3. Results of CCN closure improved significantly (overprediction improved by 37.5% and 34.6% for Pantnagar and Gaya, respectively) with the assumption of internally mixed aerosols composed of ammonium sulfate and insoluble organics. Hygroscopicity parameter calculated for these two sorties (κ=0.51 and 0.5) indicates the presence of moderately hygroscopic organic species along with some inorganic content.

Sodium nitroprusside is not associated with metabolic acidosis during intraoperative infusion in children

BackgroundSodium nitroprusside (SNP) is a potent vasodilator that has been used to induce deliberate hypotension in children during surgery involving significant blood loss, including craniofacial and spinal fusion procedures. SNP metabolism liberates cyanide, which may cause interference with cellular energy metabolism, leading to metabolic acidosis and central nervous system injury. We performed a retrospective, case–control study to determine whether the short-term intra-operative use of SNP for deliberate hypotension is associated with metabolic acidosis in children undergoing surgical procedures for craniofacial or spinal anomalies. Cyanide and thiocyanate concentrations were also recorded in patients who received SNP.MethodsData from 166 children undergoing craniofacial and spinal fusion surgery between 2005 and 2010 at Lucile Packard Children's Hospital (LPCH) at Stanford were analyzed. Records from 60 patients who received SNP (SNP group) as part of a multicenter, randomized, double-blind study were compared with records from 106 eligible patients who had blood pressure reduction using anesthetic agents and did not receive SNP (control group). Metabolic acidosis was defined as serum bicarbonate (HCO3) < 18.5 mEq/L. Whole blood CN, plasma thiocyanate and urinary thiocyanate concentrations were measured in patients in the SNP group. Differences in metabolic acidosis rates between the SNP and control groups were assessed through a test of noninferiority in the rate for the SNP group with a noninferiority threshold of 0.2. A z-test was used to test the null hypothesis. The alternative hypothesis was that the difference in these rates was less than 0.2. The same noninferiority threshold of 0.2 was also used to perform separate, secondary tests for noninferiority in the proportion of patients with HCO3 levels below 18.5 mEq/L and the proportion of patients who required HCO3 administration.ResultsFewer patients in the SNP group experienced metabolic acidosis compared to the control group (31.7% vs. 36.8%, respectively; p < .001). No whole blood CN levels above the lower limit of quantification were detected in any of the 51 patients with validated CN data. Plasma and urinary thiocyanate levels were also low.ConclusionsOur findings suggest that SNP, when used for short-term deliberate hypotension, does not cause an increased incidence of metabolic acidosis compared with the use of anesthetic agents alone.Trial registrationTrial registration number: NCT00135668

In Vitro Absorption of Atmospheric Carbon Monoxide and Hydrogen Cyanide in Undisturbed Pooled Blood

Blood samples from aircraft accident victims are analyzed for carboxyhemoglobin (COHb) and cyanide ion (CN(-)). Such victims often suffer open wounds near the autopsy blood collection sites. Many aircraft crashes result in fires that fill the victim's atmosphere with smoke that is rich in carbon monoxide (CO) and hydrogen cyanide (HCN). It is important to determine whether pooled blood in those wounds may have absorbed these gases after death, which could lead one to erroneously conclude that the presence of COHb and CN(-) in blood was the result of breathing in these gases. A laboratory desiccator was used as a chamber to establish whether CO or HCN may be absorbed in undisturbed, pooled blood. COHb levels were 4.3-11.0% after exposure to CO (5,532, 8,298, 11,064, 22,129 and 33,193 ppm) for 30 and 60 min. Blood CN(-) concentrations (1.43-5.01 µg/mL) increased with exposure to HCN at 100 and 200 ppm, each at 15, 30, 45 and 60 min. The observed COHb increases do not exclude the possibility for higher COHb levels in blood exposed to highly CO-rich atmospheres, but there is a strong potential for CN(-) levels to increase by the absorption of atmospheric HCN. Thus, postmortem COHb and CN(-) levels should be carefully interpreted.

Calculated and Experimental Regularities of Cloud Microstructure Formation and Evolution

Based on the model of regular condensation it was found that at low concentrations of CN (LC mode) at a height of about 10 m from the condensation level narrow spectra of cloud drop are formed. Their dispersion quickly decreases with increasing height. For high concentrations (HC mode) broad spectra are formed immediately due to the absence of separation into growing drops and CN covered with water. The process of spectra evolution is conducted at a constant height results, in all the cases, in the appearance of asymptotic spectra with a relative width rb ≥ 0.215. To approximate these calculated asymptotic spectra, the modified gamma-distribution with the fixed parameter α = 3 and a variable parameter γ are most suitable. For the intermediate spectra applicable are the simpler mirror-transformed known distributions. The comparison of the above distributions with the experimental spectra of a fog artificially formed in the Big Aerosol Chamber (BAC) of RPA “Typhoon” and the spectra of the morning fog and super cooled stratiform clouds demonstrated their good agreement. The phenomenon of multimodal spectra formation at a sharp rise of stratiform clouds with the velocity more than 0.1 - 0.3 m/s was theoretically shown and experimentally confirmed. The effect of CN high concentrations, evolution processes and sharp fluctuations of vertical velocities on the formation of cloud spectra observed in nature is discussed.

Ferrate and Alkaline Chlorination Treatment of Cyanide-Heavy Metal Maritime Wastewater

AbstractFerrate [Fe(VI)] and alkaline chlorination (AC) were investigated for the treatment of a maritime wastewater (CN, Cd, Cu, Ni, Pb, and Zn) in a seawater matrix. AC reduced CN concentrations but large dosages were required (0.018–0.056 mol CN consumed/mol HOCl). Metal removal occurred during the first stage (pH>10) but the amount of sludge produced was large due to Mg(OH)2(S) formation. Fe(VI) was effective in oxidizing CN and removing heavy metals to low levels without pH adjustment. Fe(VI) requirements [0.12 mol CN/mol Fe(VI)] were higher than those observed for other wastes but are considered more manageable compared with HOCl. Metal removal occurred by adsorption and coprecipitation with Fe(III) oxide, which results from the oxidation of Fe(VI). During staged treatment, metal removal and CN destruction increased [2× for Cd, 3× for Cu, 2.7× for Ni, 0.12 to 0.18 mol CN consumed/mol Fe(VI)]. Fe(III) oxide was relatively easy to separate using ultrafiltration tubular membranes and the amount of slu...

Nano-structured cellulose nanocrystals-xyloglucan multilayered films for the detection of cellulase activity

Multilayered cellulose nanocrystals-xyloglucan (CN-XG) films were assembled by spincoating at two CN concentrations inducing different structural colourations. Internal structure of both films was probed by neutron reflectometry (NR) revealing different thicknesses and architectures. The impact of film structure on degradation process by cellulases was revealed by a change in colours of the films, as CN and XG are both sensitive to cellulolytic enzymes.

Rapid and highly selective dipchecking for cyanide ions in aqueous media

This article reports a simple dipping method for the detection of cyanide ions in water and biological samples, such as blood, using chitosan-gold nanoparticle (CH-Au NP) composite films prepared using CH-Au NP colloids. Here, gold nanoparticles were generated by heating (to ~80 °C) a solution of chitosan and gold chloride, where chitosan plays the dual role of reducing and stabilizing agent. The well-known chemistry of leaching of gold by cyanide is exploited here to detect cyanide ions. The CH-Au films showed the localized surface plasmon resonance (LSPR) absorption, similar to the CH-Au colloidal solution, at 534 nm. Gold nanoparticles (Au NPs) in the films are found to be dissolved quantitatively, causing a proportional decrease in intensity of the LSPR peak. Color change was observable by the naked eye above a concentration of 2 mg L(-1) of CN(-) in solution. We found a good correlation between the reduction in intensity of the absorption peak at 534 nm and concentrations of CN(-) ions as low as 0.06 mg L(-1). Most of the previously reported methods for cyanide detection involve tedious chemistry, demand the use of sophisticated instruments and still are not suitable for on-site cyanide monitoring. Our reported approach is rapid, eco-friendly, low cost, easy to use, and highly selective for cyanide detection in aqueous solution. We feel that this simple, low cost, novel and portable method is suitable particularly for third world countries, where more sophisticated aids are not so common.

Thermodynamic Analysis of Doped Titanium Dioxide Powders by Coprecipitation-Coating Process

On the basis of the mechanism of ions precipitation reaction equilibrium, the thermodynamic analysis of Men+(La3+, Ni2+, Fe3+, Al3+)-CO32--NH3•H2O system was discussed in this paper. The relation curves between total concentrations of each metal ion and pH values at different total ammonia concentrations cN and total carbon concentrations cC were obtained. The suitable pH value of the complete precipitation reaction for all metal ions was also determined. It shows that when cN = 0.010 mol•L-1 and cC = 1.000 mol•L-1, the optimal pH is 9.0 to prepare the doped titanium dioxide powders by coprecipitation-coating process and using NaHCO3 and NH3•H2O as the precipitants.

Impact of new particle formation on the concentrations of aerosols and cloud condensation nuclei around Beijing

[1] New particle formation (NPF) is one of the most important processes in controlling the concentrations of aerosols (condensation nuclei, CN) and cloud condensation nuclei (CCN) in the atmosphere. In this study, we introduce a new aerosol model representation with 20 size bins between 1 nm and 10 μm and activation-type and kinetic nucleation parameterizations into the WRF-chem model (called NPF-explicit WRF-chem). Model calculations were conducted in the Beijing region in China for the periods during the Campaign of Air Quality Research in Beijing and Surrounding Region 2006 (CARE-Beijing 2006) campaign conducted in August and September 2006. Model calculations successfully reproduced the timing of NPF and no-NPF days in the measurements (21 of 26 days). Model calculations also reproduced the subsequent rapid growth of new particles with a time scale of half a day. These results suggest that once a reasonable nucleation rate at a diameter of 1 nm is given, explicit calculations of condensation and coagulation processes can reproduce the clear contrast between NPF and no-NPF days as well as further growth up to several tens of nanometers. With this reasonable representation of the NPF process, we show that NPF contributed 20%–30% of the CN concentrations (>10 nm in diameter) in and around Beijing on average. We also show that NPF increases CCN concentrations at higher supersaturations (S > 0.2%), while it decreases them at lower supersaturations (S < 0.1%). This is likely because NPF suppresses the increases in both the size and hygroscopicity of preexisting particles through the competition of condensable gases between new particles and preexisting particles. Sensitivity calculations show that a reduction of primary aerosol emissions, such as black carbon (BC), would not necessarily decrease CCN concentrations because of an increase in NPF. Sensitivity calculations also suggest that the reduction ratio of primary aerosol and SO2 emissions will be key in enhancing or damping the BC mitigation effect.

Influences of potassium ferrocyanide on lipid oxidation of salted cod (Gadus morhua) during processing, storage and rehydration

The effects of added potassium ferrocyanide (CN) in different concentrations (2.5ppm, 7.5ppm and 100ppm), in salt, on lipid oxidation in cod during salting, storage and rehydration were examined in this study. An increase in CN concentration accelerated lipid oxidation of the salted cod, as observed by increases in lipid hydroperoxides (PV) and thiobarbituric acid-reactive substances (TBARS), as well as in the development of fluorescence compounds (δFor and δFaq). A yellow discolouration (higher b∗ value) of salted cod was associated with higher levels of oxidation derivatives. High correlation between PV, TBARS and free fatty acid (FFA), as well as between FFA and δFor, was found. The results of principal component analysis showed that TBARS, b∗ value and δFor were the strongest indicators of lipid oxidation during salting and storage.

Seasonal variations and vertical features of aerosol particles in the Antarctic troposphere

Abstract. Tethered balloon-borne aerosol measurements were conducted at Syowa Station, Antarctica during the 46th Japanese Antarctic expedition (2005–2006). The CN concentration reached a maximum in the summer, although the number concentrations of fine particles (Dp&gt;0.3 μm) and coarse particles (Dp&gt;2.0 μm) increased during the winter–spring. The CN concentration was 30–2200 cm−3 near the surface (surface – 500 m) and 7–7250 cm−3 in the lower free troposphere (&gt;1500 m). During the austral summer, higher CN concentration was often observed in the lower free troposphere, where the number concentrations in fine and coarse modes were remarkably lower. The frequent appearance of higher CN concentrations in the free troposphere relative to continuous aerosol measurements at the ground strongly suggests that new particle formation is more likely to occur in the lower free troposphere in Antarctic regions. Seasonal variations of size distribution of fine-coarse particles show that the contribution of the coarse mode was greater in the winter–spring than in summer because of the dominance of sea-salt particles in the winter–spring. The number concentrations of fine and coarse particles were high in air masses from the ocean and mid-latitudes. Particularly, aerosol enhancement was observed not only in the boundary layer, but also in the lower free troposphere during and immediately after Antarctic haze events occurring in May, July and September.

Determination of cyanide in blood by electrospray ionization tandem mass spectrometry after direct injection of dicyanogold

An electrospray ionization tandem mass spectrometric (ESI-MS-MS) method has been developed for the determination of cyanide (CN(-)) in blood. Five microliters of blood was hemolyzed with 50 μL of water, then 5 μL of 1 M tetramethylammonium hydroxide solution was added to raise the pH of the hemolysate and to liberate CN(-) from methemoglobin. CN(-) was then reacted with NaAuCl(4) to produce dicyanogold, Au(CN)(2)(-), that was extracted with 75 μL of methyl isobutyl ketone. Ten microliters of the extract was injected directly into an ESI-MS-MS instrument and quantification of CN(-) was performed by selected reaction monitoring of the product ion CN(-) at m/z 26, derived from the precursor ion Au(CN)(2)(-) at m/z 249. CN(-) could be measured in the quantification range of 2.60 to 260 μg/L with the limit of detection at 0.56 μg/L in blood. This method was applied to the analysis of clinical samples and the concentrations of CN(-) in the blood were as follows: 7.13 ± 2.41 μg/L for six healthy non-smokers, 3.08 ± 1.12 μg/L for six CO gas victims, 730 ± 867 μg for 21 house fire victims, and 3,030 ± 97 μg/L for a victim who ingested NaCN. The increase of CN(-) in the blood of a victim who ingested NaN(3) was confirmed using MS-MS for the first time, and the concentrations of CN(-) in the blood, gastric content and urine were 78.5 ± 5.5, 11.8 ± 0.5, and 11.4 ± 0.8 μg/L, respectively.

New trajectory-driven aerosol and chemical process model Chemical and Aerosol Lagrangian Model (CALM)

Abstract. A new Chemical and Aerosol Lagrangian Model (CALM) has been developed and tested. The model incorporates all central aerosol dynamical processes, from nucleation, condensation, coagulation and deposition to cloud formation and in-cloud processing. The model is tested and evaluated against observations performed at the SMEAR II station located at Hyytiälä (61° 51' N, 24° 17' E) over a time period of two years, 2000–2001. The model shows good agreement with measurements throughout most of the year, but fails in reproducing the aerosol properties during the winter season, resulting in poor agreement between model and measurements especially during December–January. Nevertheless, through the rest of the year both trends and magnitude of modal concentrations show good agreement with observation, as do the monthly average size distribution properties. The model is also shown to capture individual nucleation events to a certain degree. This indicates that nucleation largely is controlled by the availability of nucleating material (as prescribed by the [H2SO4]), availability of condensing material (in this model 15% of primary reactions of monoterpenes (MT) are assumed to produce low volatile species) and the properties of the size distribution (more specifically, the condensation sink). This is further demonstrated by the fact that the model captures the annual trend in nuclei mode concentration. The model is also used, alongside sensitivity tests, to examine which processes dominate the aerosol size distribution physical properties. It is shown, in agreement with previous studies, that nucleation governs the number concentration during transport from clean areas. It is also shown that primary number emissions almost exclusively govern the CN concentration when air from Central Europe is advected north over Scandinavia. We also show that biogenic emissions have a large influence on the amount of potential CCN observed over the boreal region, as shown by the agreement between observations and modeled results for the receptor SMEAR II, Hyytiälä, during the studied period.