Ppm In Water Research Articles

Determination of chlorobenzenes in environmental samples using solid phase microextraction, thermal desorption and analysis by gas chromatography coupled to FID, ECD, MSD, IRD detectors

A complex method was developed for the determination of chlorobenzenes in soil and groundwater samples. Samples were taken at two sites in Baranya county, where a mixture of chlorobenzene waste was deposited, causing severe contamination in the environment. Clean-up of these sites demands modern and reliable analytical methods. Several sample preparation techniques were used, such as solid phase microextraction (SPME), supercritical fluid extraction (SFE), and a recently developed thermal desorption method. The applicability of various sample preparation methods was compared by measuring recovery percentages, relative standard deviations and by investigating the matrix dependency of these values. Gas chromatography was used for quantitative determination of chlorobenzenes, using MS, IR, FID and ECD detection techniques. Detection levels were as low as 1 ppt in water, and 10 ppt in soil samples. Chlorobenzene concentration was in the range 1 ppt-1 ppm in water and 100 ppb-100 ppm in soil samples. Identification and calibration of these compounds were performed by quantitative standards. This complex analytical method can be used for rapid and precise quantitative and qualitative determination of chlorobenzenes.

Experimental pressure-volume-temperature data and an equation of state for trifluoroiodomethane (CF 3I) in gaseous phase

Some 175 pressure-volume-temperature data points in gaseous phase for trifluoroiodomethane (CF 3I) have been measured using Burnett/isochoric methods. Burnett expansion measurements were made both at 353.15 K and at 323.15 K. Based on the pressure-volume relationships established both at 353.15 K and at 323.15 K isotherms, data were collected along isochores. Data along eight isochores were measured at the temperature range from 323.15 K to 393.15 K. Data along five isochores were measured at the temperature range from 278.15 K to 323.15 K. The pressure range is from 0.19 to 1.75 MPa. The maximum total temperature uncertainty in this work is estimated to be within ± 10 mK, the maximum total pressure uncertainty in this work is estimated to be within ± 500 Pa. The present data have been correlated with a virial equation of state. This equation has a root-mean-square deviation (RMS) deviation of 0.11 % in pressure and a RMS deviation of 0.12% in density. The purity of the sample used in this work is 99.95 wt.% with 3.4 ppm of water.

Experimental vapor pressure data and a vapor pressure equation for trifluoroiodomethane (CF 3I)

Sixty four vapor pressure data points for trifluoroiodomethane (CF 3I) have been measured for the temperature range from 243.15 to 393.15 K. The maximum total pressure uncertainty of these data is estimated to be within ± 1.0 kPa. The purity of the sample used in this work is 99.95% with 3.4 ppm of water. Based on this data set, a vapor pressure equation for CF 3I has been developed. This equation contains four coefficients and correlates the measured vapor pressures within ± 0.03%.

Deletrocephalus dimidiatus Infestation in an Adult Rhea (Pterocnemia pennata)

Infection with the nematode Deletrocephalus dimidiatus was found in the distal small and proximal large intestines of a 30-month-old female rhea that had died after a prolonged illness. Numerous strongyle-like eggs were found on fecal flotation. Possible treatments include fenbendazole (60 ppm in water) and ivermectin (200 mg/kg). Preventive measures such as artificial incubation, segregation of chicks from adults, and placing chicks in uncontaminated environments may help slow or stop the transmission of the parasite.

Lipase-catalyzed enantiomeric synthesis of citronellyl butyrate

Lipases from Candida rugosa, Pseudomonas fluorescens and Rhizopus japonicus were employed in direct esterification of the different optical isomers of citronellol with butyric acid both with and without additional organic solvent. In systems with C. rugosa lipase and without addition of organic solvent, the highest ester yields in 18 h reaction were 98% for R(+)-citronellol at 12% water content and 67% for S(−)-citronellol at 18% water content, respectively. In comparison, a yield of only 65% was obtained with at otherwise similar conditions but with an optimum water content of about 18%. No ester synthesis took place in ‘dry’ n-hexane of about 1.2 ppm of water. When water content was increased to 0.1% in n-hexane system, rapid esterification occurred also in n-hexane with all three substrates, but there was little enantioselectivity. Both P. fluorescens and R. japonicus lipases exhibited somewhat higher initial rates for citronellyl butyrate synthesis, with greater than 80% yield with R(+)-citronellol in 4 h.

Evaluation of a rodent peroxisome proliferator in two species of freshwater fish: Rainbow trout ( Onchorynchus mykiss) and Japanese medaka ( Oryzias latipes)

Rainbow trout ( Onchorynchus mykiss) and Japanese medaka ( Oryzias latipes) were exposed to the hypolipidemic drug gemfibrozil, a known rodent peroxisome proliferator. Trout were injected (i.p.) daily for 2 weeks at doses of 0, 46, 87, or 152 mg/kg/day. Medaka were exposed to the nominal concentrations of 0, 1.25, 2.5, or 5 ppm in water for 2 weeks in a static-renewal system. Peroxisome proliferation was assessed by measuring fatty acyl-CoA oxidase (FAO) activity, peroxisomal bifunctional enzyme (PBE) quantity, and changes in liver-to-body weight ratios (LWR). Results indicate that a mild peroxisome proliferative response was observed in rainbow trout (significant increases in FAO activity at all dose levels and in LWR at the highest dose level). Medaka demonstrated a significant increase in PBE at the highest dose level, while nonsignificant increases in FAO activity were observed at the mid- and high-dose levels.

The efficacy of ivermectin jetting fluid for control of blowfly strike on sheep under field conditions

Seventeen trials involving 5737 sheep were conducted to test the efficacy of ivermectin jetting fluid (30 ppm in water) for the control of blowfly strike when applied to sheep either by standard hand jetting or through an automatic jetting race. Sheep were observed for up to 14 weeks after treatment and all strikes recorded. The level of fly challenge varied between trials, resulting in strike rates in untreated sheep ranging between 0 and 94%. At 12 weeks after treatment there were 93% fewer strikes in hand jetted sheep and 84% fewer strikes in machine jetted sheep when compared with untreated sheep. At this time and point there was a 90%, 86% and 93% reduction in poll, body and breech strikes, respectively, when hand jetting was used, whereas machine jetting reduced poll, body, breech and pizzle strikes by 84%, 81%, 79% and 100%, respectively.

Age dependence of O6-methylguanine-DNA methyltransferase activity and its depletion after carcinogen treatment in the teleost medaka (Oryzias latipes)

O6-Methylguanine-DNA methyltransferase (O6-MT) is considered to play an important role in the repair of DNA lesions induced by alkylating carcinogens in a wide range of animals. The activity of O6-MT was compared in liver extracts from the teleost medaka (Oryzias latipes) at various ages (3–5 years old) reared under natural conditions. O6-MT activity decreased significantly with advancing age.When medaka were exposed continuously to the alkylating agent methylazomethanol (MAM) acetate at levels of 0.1, 0.15 and 0.3 ppm in water, O6-MT activity was markedly reduced from days 1 to 7, with a slight increase thereafter. Furthermore, when fish were exposed to MAM acetate at levels of 1–2 ppm for 1 h and then maintained in normal tap water, O6-MT activity remained suppressed for 2 weeks, followed by a partial recovery.

Leachability and Biodegradation of High Concentrations of Phenol and o-Chlorophenol

ABSTRACT The treatability of phenol and o-chlorophenol by solidification/stabilization and phenol by biodegradation was investigated. The effect of two concentrations, 0.1 and 2% of contaminant in cement (equivalent to 2,000 and 40,000 ppm in water), on the setting and solidification process of Type I Portland cement was studied. Leachability of these phenolic compounds from the solidified cement matrix, cured up to 180 days, was evaluated using the U.S. EPA recommended Toxicity Characteristic Leaching Procedure (TCLP) and the American Nuclear Society's ANS 16.1 leaching test. Changes in microstructure of the cement due to the addition of phenol was studied using the X-ray diffraction technique. A power law has been proposed to quantify the phenol leached from the solidified cement matrix during the TCLP test. The phenolic compounds affected the setting time and strength of the solidified cement. Biodegradation of phenol up to 1500 ppm was investigated in batch reactors using an acclimated sludge. The act...

Rapid and Sensitive Screening Method for the Determination of Carbaryl and Propoxur Using p-Nitroaniline

Abstract A rapid screening method for the determination of carbaryl and propoxur using p-nitroaniline is described. Carbaryl and propoxur are determined spectrophotometrically: carbaryl forms a stable blue coloured species with diazotized p-nitroaniline in a fairly alkaline medium while propoxur forms a purple coloured species with the same reagent under similar conditions. The blue and purple coloured species are extracted into 3-methyl-1-butanol showing absorbance maxima at 605 and 540 nm, respectively. The relationship between absorbance and concentration is linear in the range of 0.12 - 0.96 ppm and 0.19–1.5 ppm, respectively for carbaryl and propoxur. The method can successfully be applied for the determination of carbaryl and propoxur to levels as low as 0.04 and 0.06 and 0.12 and 0.19 ppm in water and grain samples, respectively.

Spectroelectrochemical study of the anion effect on the transient redox behavior of poly( N-methylpyrrole) in anhydrous acetonitrile

Polymerization of N-methylpyrrole and the transient redox behaviour of the polymeric film were studied by spectroelectrochemical methods in the presence of BF 4 −, ClO 4 − and PF 6 − in an acetonitrile solution containing 10 ± 1 ppm of water. The doping levels and the rate of absorbance changes at different potentials were determined and compared with those obtained for polypyrrole. In poly( N-methylpyrrole) BF 4 − behaves in a similar way to ClO 4 −, in contrast with polypyrrole. This is interpreted as evidence that the BF 4 −-polymer interaction in polypyrrole occurs via the NH bonds which are absent in poly( N-methylpyrrole).

Liquid Chromatographic Determination of Acifluorfen in Soil and Water

An analytical method based on the use of a liquid chromatograph equipped with a UV detector was developed for the determination of acifluorfen in soil and water. Acifluorfen was extracted from soil in methanol-0.10N NaOH (80 + 20 v/v) and from water by partition with dichloromethane. Solvent partitioning and solid-phase extraction were used to separate acifluorfen from major interfering sample components. Average recoveries from soil at 1, 0.1, and 0.01 ppm fortification levels were 95.1 +/- 3.4, 92.6 +/- 2.9, and 73.9 +/- 3.0%, respectively. Recoveries from water spiked at levels from 0.01 to 1 ppm averaged 96.5 +/- 5.4%. Method limits of detection were 0.006 ppm in soil and 0.003 ppm in water.

Wire Aging of Hydrocarbon Gases with TMAE Additions

We report on experimental results describing wire aging properties of the CRID/RICH detectors in the TMAE gas environment. This test used 7, μm and 33 μm diameter carbon fibers, and 20 μm diameter gold-plated tungsten wires as sense wires, and operated in gas mixtures of either CH4 or C2H6 at 1 atm, together wth 0.6 Torr of the photoionizing vapor TMAE (tetrakis dimethylamino ethylene), which serves as a photocathode in the CRID detectors. The wires were damaged by the Fe55 X-rays. This paper is based on irradiation of 20 wires, each being a separate test. The gas purity was consistent with requirements of CRID detectors (< 1 ppm of oxygen, < 1 ppm of water). The test explored the aging as a function of wire diameter, wire material, gas flow, gas temperature, rate of radiation and gas type. Several chemical analyses of the deposit samples were performed (FTIR, ESCA and GC-MS techniques).

The effect of gibberellins A4+7 on fruit set and seed set in unpollinated and pollinated ‘Sonia’ roses

The effect of GA4+7 (GA) on fruit and seed set of ‘Sonia’ roses unpollinated and pollinated with ‘Ilona’, was studied. GA at 0, 10, 50, 250 or 1250 ppm in water with 25% iso-propyl alcohol was applied 0, 7 or 14 days after emasculation. In general, GA improved fruit and seed set, and induced heavier, earlier ripening fruits. In the unpollinated and pollinated categories fruit weight and the number of achenes per fruit in comparable treatments were about the same. In the unpollinated category all achenes were parthenocarpic. In the pollinated category, 10 and 50 ppm GA after 14 days more than doubled the number of achenes per pollinated flower. Achenes with or without an embryo are a probable condition for fruit set. Effects of GA are discussed.

Composition of Surface Layers on Li Electrodes in PC, LiClO4 of Very Low Water Content

Surface layers formed on Li in PC, with less than 1 ppm of water have been analyzed by use of IR spectroscopy, SIMS, ESCA, low angle x‐ray diffraction, and SEM. Electrodeposited Li showed a highly porous micromorphology with surface layers containing primarily a partially chlorinated hydrocarbon polymer and lithium carbonate. The carbonate is mostly present in the inner film regions, the polymer in the outer. Perchlorate decomposes to chlorine compounds of lower valences, with higher‐valent chlorine found in the outer film regions and lower‐valent in the inner.

Thin -layer Chromatographic Separation and Identification of Carbofuran and Two Carbamate Metabolites and their Dinitrophenyl Ethers

Abstract Residues of carbofuran and its 2 carbamate metabolites in fortified fresh water, a sandy loam soil, and plant tissues were extracted with HCl, partitioned into methylene chloride and cleaned up on deactivated Florisil. Aliquots of extracts were chromato-graphed on silica gel G and GF plates and carbofuran, 3-hydroxycarbofuran, and 3-ketocarbofuran were hydrolysed into their 7-phenols with KOH spray. Spots were visualized with either p-nitrobenzenediazonium fluoroborate or 2,6-dibromobenzo-quinone-4-chloroimine. The characteristic color of spots before and after spraying with KOH or with either of the chromogenic reagents in ordinary light and under UV light helped in identification and differentiation of the compounds. As low as 0.05ppm in water and 0.2ppm in soil or strawberry, lettuce, carrots, peas and potatoes could be detected. 3-Hydroxycarbofuran in the remaining extracts was converted into 3-ethoxycarbofuran and the compounds were converted into their dinitrophenols and chromatographed on silica gel GF. Good separation of compounds was obtained but the limit of detection was 0.1 ppm in water and 0.3 ppm in soil and plant tissues. The procedures were applicable to field-treated rutabaga samples and useful in identity confirmation.

Analysis of liquid samples by capillary gas chromatography and helium ionization detection

Misunderstandings and misconceptions have held back the use of the sensitive helium ionization detector, particularly for the analysis of liquid samples. Some recent work on this detector and the development of fused-silica capillary columns have led to new applications utilizing both tools. In this report we evaluated helium ionization detector applications for the analysis of liquid samples. The water content of various solvents and reagents was determined using a split injection technique and a Carbowax fuxed-quartz column. We used both isothermal and temperature-programmed conditions. Concentrations as low as 2 ppm of water were detected. The system is linear up to 700 ppm although the lower detection level is dependent upon the water present in the system blank. Other potential applications as well as the advantages and limitations of the helium ionization detector will be discussed.

Breast Milk and Fluoride

It is recommended that full fluoride dosage (0.25 mg/day) be given to babies that are completely breast-fed (regardless of local water fluoride content) because significant amounts are not passed in breast milk. However, if the infant drinks "some" fluoridated water how much is significant to affect the safety of exogenous fluoride dosage? I have not seen this question referred to in the literature. Calculations are shown in the Table. See table in the PDF file Based on these calculations, if an infants drinks approximately 8 oz per day of 1 ppm of water, no fluoride should be used.

Drag Reducing Polymer in Helicoidal Flow

A novel flow configuration was explored for the study of the behavior of drag reducing polymers. A screw pump consisting of a smooth cylinder and a concentrically placed screw was used to create a strongly three-dimensional but essentially laminar flow. In the first phase of the study, the static pressure head developed by the screw pump was measured as a function of polymer concentration (polyox 10 to 100 ppm in water). A large increase of the developed head was observed that behaved in an analogous manner to drag reduction as far as concentration and straining of the polymer solution was concerned. In the second phase of the study, a new apparatus was constructed and the additional parameter of a superimposed through flow was included and the degree of failure of the superposition principle was established. Sensitivity of the phenomenon to chemicals like HCl, HNO3, and NaOH in the polymer solution was also studied. When the effect of these chemicals on the polymer solution flow behavior was presented in terms of the pH value of the polymer solution, it showed a similar trend to those observed in drag reduction.

Application of Large Bore Coated (LBC) Columns to Flavor Analysis of Beverages and Confections

ABSTRACTA large bore coated (LBC) column consisting of 25 ft ×¼ in. o.d. aluminum tubing internally coated with silicone rubber can extract flavors from beverages and dissolved confections. The beverage or solution is simply poured through the column. The column is washed with water, dried with nitrogen, and the trapped organics transferred with heat and nitrogen to a porous polymer pre‐column sized to fit the tube oven attached to the injector of the gas chromatograph. A model system of peppermint oil at 2.5 ppm in water showed that quantitative recovery of components in the ppb range was possible. Recovery factors were investigated, revealing interference from colloidal systems as in milk and beer. The LBC column method for flavors in carbonated beverages was compared with solvent extraction and nitrogen sparging methods. Results were comparable.