• Journal of Preventive Medicine and Public Health
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• v.41 no.3
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• pp.195-199
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• 2008

Objectives : Malondialdehyde (MDA), a lipid peroxidation by-product, has been widely used as an indicator of oxidative stress. Urinary 2-naphthol, a urinary PAH metabolite, is used as a marker of ambient particulate exposure and is associated with lung cancer and chronic obstructive pulmonary disease. However, the stability and intra-individual variation associated with urinary MDA and 2-naphthol have not been thoroughly addressed. The objective of this study was to assess the stability and intra-individual variation associated with urinary MDA and 2-naphthol. Methods : Urine samples were collected from 10 healthy volunteers (mean age 34, range $27{\sim}42$ years old). Each sample was divided into three aliquots and stored under three different conditions. The levels of urinary MDA and 2-naphthol were analyzed 1) just after sampling, 2) after storage at room temperature ($21^{\circ}C$) for 16 hours, and 3) after storage in a $-20^{\circ}C$ freezer for 16 hours. In addition, an epidemiological study was conducted in 44 Chinese subjects over a period of 3 weeks. The urinary MDA and 2-naphthol were measured by HPLC three times. Results : There was no difference in the levels of urinary MDA and 2-naphthol between the triplicate measurements (n=10, p=0.84 and p=0.83, respectively). The intra-class correlation coefficients (ICC) for urinary MDA and 2-naphthol were 0.74 and 0.42, respectively. However, the levels of PM2.5 in the air were well correlated with the levels of both MDA and 2-naphthol in the epidemiological study. Conclusions : These results suggest that urinary MDA and 2-naphthol remain stable under variable storage conditions, even at room temperature for 16 hours, and indicate that these markers can be used in epidemiological studies involving various sample storage conditions. The intra-CC of urinary 2-naphthol and MDA were acceptable for application to epidemiological studies.

• Analytical Science and Technology
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• v.10 no.4
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• pp.256-263
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• 1997

The new naphthol-containing hexadentate ligands, 1,12-bis (2-naphthol)- 2,5,8,11-tetraazadodecane 4HCl (nptr) and 1,14-bis(2-naphthol)- 2,6,9,13- tetraazatetradodecane .4HCl (npptr) were synthesized and characterized by elemental analysis, IR, NMR, and mass spectrometry. Acid dissociation constants and stability constants of Co(II), Ni(II). Cu(II), and Zn(II) complexes were determined at $25.0^{\circ}C$ and ionic strength ($\mu$)=0.10M($KNO_3$) by potentiometry. The relationship between basicity and stability constants of ligands containing aliphatic amines and 2-naphthol were studied.

• Journal of Environmental Science International
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• v.14 no.5
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• pp.499-511
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• 2005

This study was performed to determine the effects of genetic polymorphisms, such as glutathione S-transferase ${\mu}1(GSTM1)$, glutathione S-transferase ${\Theta}1\;(GSTM1)$, glutathione S-transferase ${\pi}l (GSTP1)$, aryl hydrocarbon N-acetyltransferase 2 (NAT2), cytochrome P450 2E1 (CYP2E1), cytochrome P450 1A1 (CYP1A1) on the concentrations of urinary 1-hydroxypyrene (1-OHP) and 2-naphthol in general population with no occupational exposure to polycyclic aromatic hydrocarbons (PAHs). Study subjects were 257 men who visited a health promotion center in Susan. A questionnaire was used to obtain detailed data about age, smoking, drinking, body fat mass, intake of fat etc. Urinary l-OHP and 2-naphthol concentration were analyzed by HPLC system with a fluorescence detector. A multiplex PCR method was used to identify the genotypes for GSTM1 and GSTT1. The polymorphisms of GSTP1, NAT2, CYP1A1 and CYP2E1 were determined by the polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) method. Urinary 1-OHP concentration was higher in deleted genotype of GSTM1, increased as smoking and alcohol drinking increased. Urinary 2-naphthol concentration was also rely on the age and smoking. Neither genetic polymorphism nor drinking-related factors were significantly related to urinary 2-naphthol concentration. No significant relation was found between physical characteristics and concentrations of urinary PAHs metabolites in the subjects, but the geometric mean of urinary 1-OHP and 2-naphthol was higher in the group with higher value compared to median value. These data suggest that in general population occupationally not exposed to PAHs, urinary concentration of PAHs metabolites is influenced by smoking, alcohol drinking and deleted genotype of GSTM1 in 1-OHP and smoking in 2-naphthol.

• Korean Chemical Engineering Research
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• v.46 no.2
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• pp.279-285
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• 2008

The etherification of 2-naphthol with ethanol has been carried out over various solid acid catalysts. CNS, CNSWS, SCMS, MCF, and SBA-15 with and without sulfonic acid were used in this study as solid acid catalysts. The conversion of 2-naphthol and the selectivity of 2-naphthyl ethyl ether were obtained at reaction temperature = $180^{\circ}C$, $LHSV=1h^{-1}$, ethanol/2-naphthol molar ratio = 20 using a fixed-bed down flow reactor. The conversion of 2-naphthol and the selectivity of 2-naphthyl ethyl ether over silica group catalysts were higher than them over carbon group catalysts. The conversion of 2-naphthol was 70-90% and the selectivity of 2-naphthyl ethyl ether was more than 90% over silica group solid acid catalysts. It was performed XRD, SEM, TEM, and $NH_3-TPD$ to characterize solid acid catalysts.

• Journal of Korean Society of Environmental Engineers
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• v.28 no.5
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• pp.535-542
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• 2006

In this study, removals of 1-naphthol by oxidative-coupling reaction using birnessite, one of natural Mn oxides present in soil, was investigated in various experimental conditions(reaction time, Mn oxide loadings, pH, etc). Removal efficiency of 1-naphthol by birnessite was high in all the experimental conditions, and UV-vis. and mass spectrometric analyses on the supernatant after reaction confirmed that the reaction products were oligomers formed by oxidative-coupling reaction. Pseudo-first order rate constants, f, for the oxidative transformation of 1-naphthol by birnessite was derived from the kinetic experiments under various amount of birnessite loadings, and using the observed pseudo-first order rate constants with respect to birnessite loadings, surface area-normalized specific rate constant, $k_{surf}$ was also determined to be $9.31{\times}10^{-4}(L/m^2{\cdot}min)$ for 1-naphthol. In addition, the oxidative transformation of 1-naphthol was found to be dependent on solution pH, and the pseudo-first order rate constants were increased from 0.129 at pH 10 to 0.187 at pH 4.

• Journal of the Korean Chemical Society
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• v.30 no.2
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• pp.152-158
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• 1986

The dissociation constants of 4-Cl-1-naphthol, 6-Br-2-naphthol and $8-NH_2-2-naphthol$ in aqueous solution were measured by spectroscopic method in the temperature range from 25 to 40${\circ}C$ and pressure up to 2000bar. The dissociation constants were decreased as the substituents were inserted in naphthol f rom $4.4{\times}10^{-10}\;to\;5.82{\times}10^{-11}$ as chloride compound and $2.5{\times}10^{-10}\;to\;3.44{\times}10^{-11}\;or\;4.21{\times}10^{-11}$ as bromine or amino compounds, respectively. This decrease can be explained with the I-or R-effects of substituents. From the dissociation constants various thermodynamic properties were calculated and discussed the characteristics of the dissociation reaction.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2005.04a
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• pp.49-52
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• 2005

In this study, abiotic transformation of 1-naphthol via oxidative-coupling reaction was evaluated using Mn oxide which is ubiquitous in natural soils. The transformation of 1-naphthol catalyzed by synthetic birnessite $({\delta}-MnO_2)$ followed pseudo-lst order reaction, and the rate constants was in the range of $0.053{\sim}0.13\;min^{-1}$ with birnessite loadings of $12.5{\sim}50\;mg/20\;mL$. Since the oxidation of 1-naphthol was occurred on the reactive surface of the oxide particles, the rate constants with various birnessite loadings were correlated with birnessite surface area concentration. The correlation showed a strong linearity, which confirms the supposition of the surface reaction. From the correlation, therefore, the surface area normalized rate constant, $k_{surf}$, was determined to be 0.032 $L/m^2\;min$.

• Journal of the Korean Chemical Society
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• v.27 no.1
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• pp.24-30
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• 1983

The polarographic behavior of 1-(2-pyridylazo)-2-naphthol (PAN) in acetonitrile as an aprotic solvent has been investigated. The reduction of PAN in $10^{-2}$ molarity of tetraethyl-ammonium perchlorate acetonitrile solution proceeds along two one-electron steps to give the corresponding hydrazo compound. Every reduction wave was diffusion controlled and considerably reversible. The reduction mechanism of PAN in acetonitrile is estimated as follows;

• Journal of Korean Society of Environmental Engineers
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• v.29 no.9
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• pp.989-996
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• 2007

In this study, abiotic transformation of 1-naphthol(1-NP) via oxidative-coupling reaction and its reaction products were investigated in the presence of Mn oxides. The reaction products were characterized for their relative polarity using solvent extraction experiment and reverse-phase HPLC, and for structure using CCMS and LC/MS, and for absorption characteristics using UV-Vis spectrometry. The reaction products present in aqueous phase were more polar than parent naphthol and comprised of 1,4-naphthoquinon(1,4-NPQ) and oligomers such as dimers and trimers. Hydrophilic component present in water phase after solvent$(CH_2Cl_2)$ extractions was identified as naphthol polymerized products having molecular weight(m/z) ranging from 400 to 2,000, and showed similar UV-Vis. absorption characteristics to that of foil fulvic acid. Transformation of 1,4-NPQ, which is non-reactive to Mn oxide, to the polymerized products via cross-coupling reaction in the presence of 1-NP was also verified. In this experimental conditions(20.5 mg/L, 1-NP, 2.5 g/L $MnO_2$, pH 5), the transformation of 1-NP into the oligomers and polymerized products were about 83% of initial 1-NP concentrations, and more than 30% of the reaction products was estimated to be water insoluble fractions, not extracted by $H_2O$ methanol. Results from this study suggest that Mn oxide-mediated treatment of naphthol contaminated soils can achieve risk reduction through the formation of oligomers md polymer precipitation.

• Bulletin of the Korean Chemical Society
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• v.30 no.7
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• pp.1516-1520
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• 2009

A sensitive technique for the determination of trace Co(II) in various samples after column preconcentration by adsorbing onto silica gel loaded with 1-nitroso-2-naphthol was developed. Several experimental conditions, such as pH of sample solution, the amount of silica gel loaded with 1-nitroso-2-naphthol, the flow rate for adsorption and so forth, were optimized. The interfering effects of diverse concomitant ions were investigated. Fe(III) interfered with more than any other ions, but the interference by Fe(III) was completely eliminated by adjusting the amount of silica gel loaded with 1-nitroso-2-naphthol to 0.30 g. The dynamic range, the correlation coefficient ($R^2$), and the detection limit obtained by the proposed technique were 3.0-140.0 ng m$L^{-1}$, 0.9942, and 1.81 ng m$L^{-1}$, respectively. For validating the technique, the aqueous samples (tap water, reservoir water, stream water, and wastewater) and the plastic samples were used as real samples. Recovery yields of 93.0-107.0% were obtained. These measured data were not different from ICP-MS data at the 95% confidence level by F test. Based on the results of the experiment, it has been found that the proposed technique can be applied to the determination of Co(II) in various real samples.