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At least 1,063 records · Page 59Linked to original sources
PubMed2005

Simple and cost-effective liquid chromatographic method for determination of pyrimethamine in whole blood samples dried on filter paper.

A cost-effective HPLC method for determination of pyrimethamine (PYR) in human whole blood samples dried on filter paper (Whatman) is reported. Trimethoprim (TMP) was used as an internal standard. Whole blood spiked with PYR was transferred (100 microl) onto filter paper and dried at room temperature. Capillary blood samples (100 microl) after ingestion of three tablets of sulfadoxine-pyrimethamine (SP) by one subject were also tested. PYR and an internal standard (IS) TMP were extracted into di-isopropyl ether as bases and then re-extracted with 150 microl mobile phase. A C-18 column was used and the mobile phase consisted of phosphate buffer (0.05 M, pH 5):acetonitrile:concentrated perchloric acid (750:300:2.5, v/v/v). The absorbances of PYR and IS were monitored at 270 nm. The limit of quantification was 40 ng/ml. The within- and between-assay coefficient of variations were <10% at the limit of quantification.

Antimalarials↗
PubMed2004

Climate change policies and capital vintage effects: the cases of US pulp and paper, iron and steel, and ethylene.

Changes in material use, energy use and emissions profiles of industry are the result of complex interrelationships among a multitude of technological and economic drivers. To better understand and guide such changes requires that attention is paid to the time-varying consequences that technology and economic influences have on an industry's choice of inputs and its associated (desired and undesired) outputs. This paper lays out an approach to improving our understanding of the dynamics of large industrial systems. The approach combines engineering and econometric analysis with a detailed representation of an industry's capital stock structure. A transparent dynamic computer modeling approach is chosen to integrate information from these analyses in ways that foster participation of stakeholders from industry and government agencies in all stages of the modeling process-from problem definition and determination of system boundaries to generation of scenarios and interpretation of results. Three case studies of industrial energy use in the USA are presented-one each for the iron and steel, pulp and paper, and ethylene industry. Dynamic models of these industries are described and then used to investigate alternative carbon emissions and investment-led policies. A comparison of results clearly points towards two key issues: the need for industry specific policy approaches in order to effectively influence industrial energy use, fuel mix and carbon emissions, and the need for longer time horizons than have typically been chosen for the analysis of industrial responses to climate change policies.

Air Pollution↗
PubMed2005

How to reconcile environmental and economic performance to improve corporate sustainability: corporate environmental strategies in the European paper industry.

This paper discusses the relationship between environmental and economic performance and the influence of corporate strategies with regard to sustainability and the environment. After formulating a theoretical model, results are reported from an empirical analysis of the European paper manufacturing industry. New data are used to test hypotheses derived from the theoretical model, using environmental performance indices representing different corporate environmental strategy orientations. In particular, an emissions-based index largely reflecting end-of-pipe strategies and an inputs-based index reflecting integrated pollution prevention are distinguished. For the emissions-based index, a predominantly negative relationship between environmental and economic performance is found, whereas for the inputs-based index no significant link is found. This is consistent with the theoretical model, which predicts the possibility of different relationships. The results also show that for firms with pollution prevention-oriented corporate environmental strategies, the relationship between environmental and economic performance is more positive, thus making improvements in corporate sustainability more likely. Based on this last insight, managerial implications of this are discussed with regard to strategy choices, investment decisions and operations management.

Conservation of Natural Resources↗
PubMed2006

Preparation and sorption properties of porous materials from refuse paper and plastic fuel (RPF).

Porous materials consisting of activated carbon and amorphous CaO-Al(2)O(3)-SiO(2) (CAS) compound were prepared from refuse paper and plastic fuel (RPF), (a mixture of old paper and plastic) by carbonizing and/or activating treatments. Samples formed by chemical activation using K(2)CO(3) showed a high specific surface area (S(BET)) of 1330 m(2)/g but a lower ash content due to being washed after activation. By contrast, samples prepared by physical activation using steam showed rather lower S(BET) (510 m(2)/g) due to higher ash contents. The physically activated samples showed much higher uptake properties for Ni(2+) (a representative heavy metal) and phosphate ions (a representative of a harmful oxyanion) than the chemically activated samples because of the higher content of amorphous CAS in the former samples. By contrast, the chemically activated samples showed higher uptake for methylene blue (MB, a representative organic material) than the physically activated samples because of the higher activated carbon content of higher surface area. Although differences in the sorption properties for Ni(2+), phosphate ion and MB were found between the physically and chemically activated samples, both samples show excellent multiple sorption properties for cation-anion combinations and inorganic-organic sorbents.

Adhesives↗
PubMed2004

Evaluation of a norovirus sampling method using sodium dodecyl sulfate/EDTA-pretreated chromatography paper strips.

Noroviruses are the most common cause of nonbacterial gastroenteritis outbreaks. A novel method was tested that utilizes sodium dodecyl sulfate (SDS)/EDTA-pretreated chromatography paper strips to collect and transport norovirus-containing fresh stool samples. As confirmation, the strips were infected with different dilutions of human norovirus-containing faeces and stored at different temperatures (-80, -20, 4 degrees C, room temperature and 37 degrees C). Reverse transcription (RT)-PCR analysis was carried out after storage of the strips for 1, 7, 14, 60, and 120 days. The presence of amplifiable norovirus RNA on the strips was inversely correlated with the duration of storage and the storage temperature. Norovirus RNA remained detectable for a sufficient amount of time at room temperature or even in warmer climatic conditions to allow transportation of the samples from a field site to a reference laboratory using regular postal mail. To prove that viral infectivity was lost upon contact with the SDS/EDTA-treated strips, feline calicivirus F9 (10(7) TCID(50)/ml) was loaded onto the strips. After elution and dialysis, no cytopatic effect could be observed upon incubation on Crandell-Reese feline kidney cells. The SDS/EDTA-pretreated chromatography filter paper strips are an inexpensive, biosafe and adequate method to collect, transport and store norovirus samples.

Antiviral Agents↗
PubMed2004

A low-resolution non-invasive NMR characterization of ancient paper.

The use of a portable NMR device allows a non-invasive investigation of the paper in order to assess the state of conservation of books and documents of historical or artistic interest. The NMR investigation has been found mainly on relaxation measurements whose results seem compatible with different relaxation rates in crystalline and amorphous cellulose domains. By a simplified physical picture based on spin-diffusion it appears possible to detect the alteration of the crystalline/amorphous cellulose balance and therefore to get information on some deterioration processes of paper. The use of a portable NMR device shows great potentiality because of its safe and simple in situ approach to Cultural Heritage documents. In this work, we present a research carried out on a 17th century manuscript.

Anthropology, Cultural↗
PubMed2005

Combustion characteristics of paper mill sludge in a lab-scale combustor with internally cycloned circulating fluidized bed.

After performing a series of batch type experiments using a lab-scale combustor, consideration was given to the use of an internally cycloned circulating fluidized bed combustor (ICCFBC) for a paper mill sludge. Operation parameters including water content, feeding mass of the sludge, and secondary air injection ratio were varied to understand their effects on combustion performance, which was examined in terms of carbon conversion rate (CCR) and the emission rates of CO, C(x)H(y) and NO(x). The combustion of paper mill sludge in the ICCFBC was compared to the reaction mechanisms of a conventional solid fuel combustion, characterized by kinetics limited reaction zone, diffusion limited reaction zone, and transition zone. The results of the parametric study showed that a 35% water content and 60 g feeding mass generated the best condition for combustion. Meanwhile, areal mass burning rate, which is an important design and operation parameter at an industrial scale plant, was estimated by a conceptual equation. The areal mass burning rate corresponding to the best combustion condition was approximately 400 kg/hm(2) for 35% water content. The secondary air injection generating swirling flow enhanced the mixing between the gas phase components as well as the solid phase components, and improved the combustion efficiency by increasing the carbon conversion rate and reducing pollutant emissions.

Air Pollutants↗
PubMed2006

A review of secondary sludge reduction technologies for the pulp and paper industry.

The broader application of the activated sludge process in pulp and paper mills, together with increased production, have amplified sludge management problems. With sludge management costs as high as 60% of the total wastewater treatment plant operating costs, and increasingly stringent environmental regulations, it is economically advantageous for pulp and paper mills to reduce their biosolids production. In order to provide a state-of-the-art review of secondary sludge reduction technologies, we have considered the scenarios of lower sludge production through process modifications, and waste-activated sludge reduction through post-treatment. A critical evaluation of all candidate reduction technologies indicates that sludge reduction through treatment process changes appears more appealing than post-treatment alternatives. The former approach offers a clear advantage over the latter in that the treatment process changes reduce sludge production in the first place, thus decreasing sludge management cost. Although it is technically feasible to eliminate the need for sludge disposal, it is unlikely to be economically feasible at this time.

Anaerobiosis↗
PubMedDate not supplied

Efficacy of tear eosinophil cationic protein level measurement using filter paper for diagnosing allergic conjunctival disorders.

PURPOSE: We investigated the efficacy of the tear sampling method using a filter paper to evaluate eosinophil cationic protein (ECP) levels in patients with allergic disorders. METHODS: Subjects were an allergic group comprising patients with allergic conjunctivitis, vernal keratoconjunctivitis, or atopic keratoconjunctivitis, a Sjögren group comprising patients with secondary Sjögren syndrome, and a control group comprising healthy volunteers. Tears were sampled using the Schirmer Method I and the sample was eluted from the filter paper in 50 microL of elution solution containing phosphate buffer solution with 0.5 M NaCl + 0.1% Tween 20. Then the ECP concentration in the elution sample was determined by the enzyme-linked immunosorbent assay method. RESULTS: Tear ECP level in the allergic group was significantly higher than the levels in the other two groups (P <.01 for the Sjögren group and P <.001 for the control). Furthermore, the tear ECP level of each allergic disease subgroup in the allergic group was significantly higher than that in the control group. CONCLUSIONS: This method of determining tear ECP concentration is useful not only to diagnose allergic conjunctival disorders but also to evaluate their clinical stages.

Adolescent↗
PubMed1981

Paper chromatographic separation of phosphate esters, tricarboxylic cycle acids and amino acids in extracts from malaria parasites.

A paper chromatographic method for the separation and identification of complex mixtures of phosphate esters, tricarboxylic cycle acids and amino acids in biological extracts is described. The method has been applied to the investigation of carbohydrate metabolism pathways in the intraerythrocytic, simian malaria parasite Plasmodium knowlesi; on treatment of parasitized erythrocytes with [U-C14]glucose, a perchloric acid extract was prepared and separated by chromatography on Whatman 31 ET filter-paper. A simple procedure for the measurement of the specific activities of radioactive compounds without prior elution from the chromatographic support is also described.

Amino Acids↗
PubMed1978

Separation of radioactive histamine and some of its metabolites by one-dimensional paper chromatography.

A simple one-dimensional paper chromatograph technique is described for the separation of radioactive histamine and some of its metabolites in blood and tissues. After removal of protein, the supernatant fluid (200 microliter) is subjected to two-stage one-dimensional paper chromatography. This enables large numbers of samples to be chromatographed simultaneously. Using this technique in conjunction with liquid scintillation counting, it was possible to monitor the small amounts (0.02 nCi) of radioactive histamine and its metabolites in serial blood samples.

Animals↗
PubMed2001

Qualitative detection of selenium in fortified soil and water samples by a paper chromatographic-carboxyl esterase enzyme inhibition technique.

Thevetia peruviana seed carboxyl esterase was employed as a biosensor for the detection of selenium compounds by an enzyme inhibition technique on paper chromatograms. The selenium compounds (sodium selenite and selenium dioxide) appeared as white spots on a magenta background due to the inhibition of Thevetia peruviana seed carboxyl esterase (substrate 1-naphthyl acetate, coupling reagent Fast blue B salt). The minimum detectable amounts were about 5 microg of sodium selenite and 5 microg of selenium dioxide. Many other animal and plant carboxyl esterases gave no inhibition spot under the same conditions. Soil and water samples were fortified with sodium selenite and selenium dioxide. A procedure for preparing test solutions and conditions for paper chromatography was established.

Apocynaceae↗
PubMed1978

Qualitative detection of placidyl (ethchlorvynol) alone or in combination with poly-drugs in drug abuse urine screening programs using ion-exchange paper and/or liquid-liquid extraction.

Two procedures for the detection of ethchlorvynol are presented. Procedure I involves the use of SA-2-cation-exchange resin loaded paper. The use of multiple ion-exchange resin papers is proposed in a sequence that enables the detection of amphetamines, barbiturates, phenothiazines, propoxyphene (Darvon), phencyclidine, cocaine (benzoyl ecgonine), pentazocine (Talwin) and benzodiazepines in addition to ethchlorvynol. This procedure discusses the details of detecting ethchlorvynol in combination with the entire array of drugs of abuse depending on the needs of a clinical program. Procedure II involves the principle of liquid-liquid extraction using either raw or spent urines.

Chromatography, Ion Exchange↗
PubMed2002

Determination of toxic compounds in paper-recycling process waters by gas chromatography-mass spectrometry and liquid chromatography-mass spectrometry.

Three analytical methods were developed for the determination of toxic compounds in recirculating waters of a paper-recycling industry. Three main groups of compounds were considered: (i) wood extractives originated from the raw material; (ii) biocides added during the production process and (iii) surfactants and other adjuvants present in the formulates of these biocides. Wood extractives considered in this study included fatty and resin acids. They were analysed by liquid-liquid extraction using methyl tert.-butyl ether, followed by gas chromatography-mass spectrometry for previous formation of the respective trimethylsilyl esters. Water samples were also extracted with Oasis HLB (copolymer [poly(divinylbenzene-co-N-vinylpyrrolidone]) solid-phase extraction cartridges of 60 mg and analysed by liquid chromatography-electrospray mass spectrometry for the determination of additives and biocides. Using these two approaches levels up to 15 mg/l for total resin and fatty acids, 5 mg/l for alkylbenzene sulfonates and 2-(thiocyanomethylthio)benzotiazol, 100 microg/l for bisphenol A and 2,2-dibromo-3-nitrilepropionamide, and 300 microg/l for nonylphenol ethoxycarboxylate were detected in process waters at different production treatment stages. These levels are of relevance since poor water quality affects the paper-recycling process, the primary water treatment process and eventually, the environmental water quality.

Chromatography, Liquid↗
PubMed2003

Preparation of cellulose samples for size-exclusion chromatography analyses in studies of paper degradation.

Hydrolytic degradation of cellulose was shown to take place during the activation procedure in distilled water during the dissolution procedure of cellulose samples from papers for size-exclusion chromatography analyses in the lithium chloride-N,N-dimethylacetamide (DMAc) solution system. The use of dilute aqueous sodium hydroxide solution in the activation procedure prevents hydrolytic degradation of cellulose during the dissolution procedure, especially in the case of samples of aged papers with low pH. The use of the freeze-drying technique provides samples of cellulose ready-made for dissolution in lithium chloride-N,N-dimethylacetamide solution.

Cellulose↗
PubMed2001

The ecology of "fecal indicator" bacteria commonly found in pulp and paper mill water systems.

Coliform bacteria have long been used to indicate fecal contamination of water and thus a health hazard. In this study, the in-mill water and external effluent treatment systems of seven typical Canadian pulp and paper mills were all shown to support the growth of numerous coliforms, especially Klebsiella Spp., Escherichia coli. Enterobacter spp., and Citrobacter spp. In all mills and most sampled locations, klebsiellas were the predominant coliforms. Although all but one of the mills had no sewage input and most disinfected their feed (input) water, all contained the most typical fecal indicator bacterium, E. coli. Many of the mill coliforms were classified as fecal coliforms by standard "MPN" and metabolic tests, but this was shown to be due to their thermotolerance, not their origin. Mill coliforms were shown not to be just simple transients from feedwater or furnish (wood), but to be continuously growing, especially in some of the primary clarifiers. Isolated mill coliforms grew very well on a sterilized raw combined mill effluent. The fecal streptococci (enterococci), alternative indicators of fecal health hazards, were common in all mills in the absence of sewage. Ten strains of E. coli isolated from four mills were all shown to be non-toxigenic strains of harmless serotypes. No salmonellas were found. Therefore, the use of total coliform, fecal coliform, enterococci, or E. coli counts as indicators of fecal contamination, and thus of health hazard in pulp and paper mill effluents or biosolids (sludges) known to be free of fecal input is invalid.

Bioreactors↗
PubMed2002

Bioaugmentation with the resin acid-degrading bacterium Zoogloea resiniphila DhA-35 to counteract pH stress in an aerated lagoon treating pulp and paper mill effluent.

Efficient and reliable removal of resin acids such as dehydroabietic acid (DhA), which are the major toxicants in pulp and paper mill effluents and form pitch interfering with papermaking, is critically important to prevent toxicity discharge and failure of paper machines. Low- and high-pH stresses sometimes occur in effluent treatment systems due to the use of large amounts of acids and alkalines in the pulping processes. We found that both low- and high-pH stresses (pH 3 and 10, respectively) decreased the removal of total organic carbon and completely inhibited the removal of DhA by the biomass of an aerated lagoon treating pulp mill effluent. The pH stresses caused changes in the bacterial community structure as assessed by ribosomal intergenic spacer length polymorphism. The pH stresses greatly reduced the indigenous DhA-degrading populations in the lagoon community. Bioaugmentation with Zoogloea resiniphila DhA-35, a DhA-degrading bacterium originally isolated from a pulp mill treatment system, restored the DhA removal by both the low- and high-pH-stressed lagoon biomass. This bacterium was persistent after introduction into the lagoon microbial community, and its cellular rRNA:rDNA ratio increased during the period of DhA removal. The introduction of strain DhA-35 changed the microbial community structure, but did not adversely affect the TOC removal by the community. This study suggests that it is feasible and potentially useful to use bioaugmentation with resin-acid-degrading bacteria such as DhA-35 to restore and enhance resin acid removal by aerated lagoon microbial communities.

Biodegradation, Environmental↗
PubMed2003

Metal ion removal from water by sorption on paper mill sludge.

Chromatographic columns packed with paper mill sludge are employed for metal ion recovery from water. The breakthrough curves show that cadmium, copper, lead and silver are removed from acid solutions (pH 2, 4); the affinity series is Pb(II)>Cu(II)>Ag(I)>Cd(II). Both the amount of metal retained and the metal-matrix interaction are pH dependent; the sorptive capacity increases with increasing pH. When the metals are present together at the same initial concentrations a competition among the different ions occurs although the affinity order remains unchanged. In metal recovery from the paper mill sludge column, the total amount of the cadmium and copper is displaced by HCl 1.0 M, 65% of the lead by HCl 0.1 M and 75% of the silver by HNO(3) 0.1 M. More than 95% of copper and lead and less than 20% of cadmium were recovered with HCl 0.1 M when the metals were present at the same time.

Industrial Waste↗