• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.25 no.3
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• pp.312-321
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• 2015

Objectives: The purpose of this study was to determine the best method to analyze PAHs at extremely low concentrations. To this end, 16 PAHswere analyzed simultaneously by GC/MS, HPLC/FLD and HPLC/UVD, and the analytical characteristics of HPLC and GC/MS were compared. Methods: This study was conducted by GC/MS and HPLC/FLD/UVD, and evaluated linearity, precision and detection limit. Standard solutions were prepared for 21 samples in the range of $0.00001{\sim}1.0{\mu}g/mL$ and the samples were divided into four groups. All samples were made in three sets and analysis was replicated seven times. Results: Sixteen PAHs could be simultaneously separated by HPLC and GC/MS, and the adequate equipment was HPLC/FLD. The retention times by HPLC were shorter than GC/MS, and HPLC had better separation for most PAHs than GC/MS. The peaks of naphthalene and naphthalene-D8 partially overlapped for GC/MS. HPLC/FLD had a 20-2000 times lower limit of detection than GC/MS and UVD. However FLD was not adequate for analyzing acenaphthylene because it has too low a fluorescence quantum yield to be detected. The precision of HPLC/FLD/UVD and GC/MS showed less than 20% at $0.001{\mu}g/mL$ PAHs and when the concentration was higher, the coefficient of variation was decreased. HPLC/FLD was better for the overall detection of limits. Conclusions: The results indicate that the HPLC/FLD method has good linear range, precision and a detection of limits from $0.00001{\sim}0.0001{\mu}g/mL$ for all 16 PAHs. This study contributes to providing useful data for analysis technology and can be applied to occupational exposure measurement for PAHs in workplaces.

• Journal of Life Science
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• v.23 no.2
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• pp.306-310
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• 2013

We compared the efficacy of the competitive ELISA method for measuring the level of urinary aflatoxin M1 (AFM1) with that of the HPLC-fluorescence detector (HPLC-FLD) method. The recovery rate of AFM1 with the ELISA method was 105% (73-124%), and the coefficient of variation of the analysis was 6.85%. The ELISA method showed a 0.20 pg/ml and 0.62 pg/ml limit of detection and limit of quantitation, respectively. In correlation analysis, the two methods showed a very strong and statistically significant correlation (R=0.96, p<0.01). However, in spite of the strong correlation, the ELISA method tended to overestimate the urinary AFM1 concentration compared to the HPLC-FLD method. These results suggest that the competitive ELISA method may be a useful technique for measuring the AFM1 level in high-throughput urine samples, but it needs to be corrected with a regression equation from regression analysis with the HPLC-FLD method.

• Journal of Soil and Groundwater Environment
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• v.14 no.6
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• pp.35-44
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• 2009

Naphthalene and TNT (2,4,6-trinitrotoluene) are defined by U.S. EPA as possible carcinogenic compounds known to have detrimental effects on the aquatic ecosystem and human body. There are, however, few researches on methods of analyzing micro-levels of naphthalene and TNT dissolved in groundwater. This study introduces and evaluates the newly developed analytical methods of measuring naphthalene and TNT in groundwater by using HPLC-FLD (Fluorescence detector) and MSD (Mass detector). The MDL, LOQ and salt effect of these methods, respectively, are compared with those of conventional methods which use HPLC-UV. For the analysis of naphthalene, HPLC-FLD was set in the maxima wavelength (Ex: 270 nM, Em: 330 nM) obtained from 3D-Fluorescence to be compared with HPLC-UV in 266 nM wavelength. The MDL ($0.3\;{\mu}g/L$) and LOQ ($2.0\;{\mu}g/L$) of naphthalene by using HPLC-FLD were approximately 80 times lower than those analyzed by HPLC-UV (MDL: $23.3\;{\mu}g/L$, LOQ: $163.1\;{\mu}g/L$). HPLC-MSD were used in comparison with HPLC-UV in 230 and 254 nM wavelength for the analysis of TNT. The MDL ($0.13\;{\mu}g/L$) and LOQ ($0.88\;{\mu}g/L$) of TNT analyzed by using HPLC-MSD were approximately 130 times lower than those obtained by using HPLC-UV in 230 nM (MDL: $16.8\;{\mu}g/L$, LOQ: $117.5\;{\mu}g/L$). The chromatogram of TNT analyzed by using HPLC-UV in 230 nM displayed elevated baseline as the concentration of ${NO_3}^-$ increases beyond 21 mg/L, while the analysis using HPLC-MSD did not demonstrate any change in baseline in presence of ${NO_3}^-$ of 63.7 mg/L which is 3.5 times higher than average concentration in groundwater. In conclusion, HPLC-FLD and HPLC-MSD may be used as suitable methods for the analysis of naphthalene and TNT in groundwater and drinking water. These methods can be applied to the monitoring of naphthalene and TNT concentration in groundwater or drinking water.

• Journal of environmental and Sanitary engineering
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• v.23 no.4
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• pp.37-44
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• 2008

In this study we developed the analytical methods for the determination of three neurotoxin; anatoxin-a, saxitoxin and neosaxitoxin using HPLC/FLD system and this analytical methods were applied to real sample; algae culture and algae extracts. For the HPLC/FLD analysis of anatoxin-a samples were concentrated on WCX(Weak Cation Exchanger) SPE and then anatoxin-a in concentrate was derivatized with NBD-F solution. Supernatant was injected on HPLC system. For the HPLC/FLD analysis of saxitoxin and neosaxitoxin samples were separated on the column and then derivatizied by post column reactor for fluorescen detection. For post column reaction of saxitoxin we feed two kinds of reaction solution; Oxidizing Reagent of which composition was periodic acid(7mM) in 50mM potassium phosphate buffer, pH 9 and acidifying reagent of which Composition was 0.5M acetic acid. The LOD value for anatoxin-a, saxitoxin and neosaxitoxin in HPLC/FLD method was 24.3 ng. $35{\mu}g/L$, $27{\mu}g/L$ respectively. We determined the anatoxin-a content of lyophilized anabaena flos-aquae and $20{\mu}g/g$ d.w. of anatoxin-a was detected. We analyzed saxitoxin and neosaxitoxin in algae culture media and extracts of lypopyllized algal cell cultured and that of Deachung reservior. Saxitoxin and neosaxitoxin in real sample were below the limit of detection. Although there are various water treatment processes for removing neurotoxins were suggested no process give simultaneous and complete removal of neurotoxins. It was cocluded that nanofiltration which reject material by size can be a process for removal of neurotoxins.

• Biomedical Science Letters
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• v.3 no.1
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• pp.29-35
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• 1997

Cardiovascular disease has been the leading cause of death among patients with chronic renal failure. Many reports have been described that homocysteine is one of the independent risk factor to the occulsive vascular disease. In this study, HPLC/FLD (high performance liquid chromatography-fluorescence detector) technique was used to measure homocysteine level in patients with chronic renal failure and normal control group. The detection limit and recovery of total plasma homocysteine using HPLC/FLD were 98.6$\pm$5.8% and 0.2 nmol/ml, respectively. The linearity of this method was established in concentration range of 2~50 nmol/ml (correlation coefficient=0.9997). The concentrations of total plasma homocysteine were 6.81$\pm$1.54 nmol/ml and 27.28$\pm$14.94 nmol/ml in normal control (n=20) and patient group (n=90), respectively (p<0.05). In this study, the HPLC/FLD method showed high sensitivity and reproducibility for a routine clinical laboratory testing. Moreover determination of homocysteine level in plasma might be useful for a biochemical marker for predicting the cardiovascular diseases and for monitoring of therapeutic effect of lowering homocysteine in patients with chronic renal failure.

• Analytical Science and Technology
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• v.12 no.1
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• pp.28-33
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• 1999

Glutathione(GSH) in biological samples was determined by high performance liquid chromatographic(HPLC) method with fluorescence detector(FLD) after monobromobimane(MBB) or 4-fluoro-7-sulfobenzofurazan(SBD-F) derivatization. The detection limit of $0.03{\mu}g/mL$ was obtained after MBB derivatization, derivative of MBB was about 200 times more sensitive than that of SBD-F. N-acetylcysteine was used as internal standard and tetrabutylammonium ion as counter ion for better separation. The determination by ion-pairing chromatography after MBB derivatization was characterized by linearity in the range between $0.08{\sim}8.33{\mu}g/mL$ with a good correlation coefficient of 0.998. By precision test appeared relative standard deviation at less than 5% at three different concentrations. This method can be used for the analysis of GSH in plasma and tissue.

• Analytical Science and Technology
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• v.28 no.6
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• pp.370-376
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• 2015

An analytical method for determining phenol considered priority pollutants of the US EPA and precursor of toxic phenolic compounds by solid-phase extraction (SPE) and high performance liquid chromatographic systems (HPLC) equipped with fluorescence and mass selective detectors have been developed. The SPE process for sample preconcentration was performed on a commercially available Oasis HLB cartridge packed with polymeric sorbents. The effect of pH, elution solvent, and elution volume on the recoveries of the analytes were investigated with HPLC/FLD. Average recovery of >87.0% was achieved with 60 mg sorbents using 5 mL of methanol as an elution solvent at pH=3.

• Korean Journal of Food Science and Technology
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• v.39 no.5
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• pp.488-493
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• 2007

A survey for total aflatoxins (aflatoxins $B_1$, $B_2$, $G_1$, and $G_2$) was conducted on 245 cereals and processed cereal products, and 148 nuts and processed nut products in Korea, for a total of 393 commercialized ed samples. The total aflatoxins were quantified by the immunoaffinity column clean-up method with high performance liquid chromatography (HPLC) - fluorescence detection (FLD), and were confirmed by liquid chromatography tandem mass spectrometry (LC-MS/MS). Total aflatoxins(AFs) were detected in 37 samples (9.4% incidence), including 2 millet samples, 1 mixed cereal (sunsik), 1 powdered malt sample, 2 processed cereal products, 6 peanut samples, 22 peanut butter samples, and 1 sample each of almonds, adlay tea, and a processed nut product. The contamination levels were $0.04-2.65{\mu}g/kg$ for aflatoxin $B_1$, and $0.04-5.51{\mu}g/kg$ for total aflatoxins. Finally, LC-MS/MS analysis of the contaminated samples was conducted to confirm the detected aflatoxins, and all 37 samples showing aflatoxins by HPLC-FLD were confirmed by LC-MS/MS.

• Korean Journal of Food Science and Technology
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• v.40 no.3
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• pp.354-359
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• 2008

A survey for zearalenone contamination was conducted on 27 soy bean samples, 27 red bean samples, 16 black bean samples, 19 seoritae samples, 14 seomoktae samples, for a total of 127 commercial Korean samples. Zearalenone was quantified by the immunoaffinity column clean-up method with high performance liquid chromatography-fluorescence detection (HPLC-FLD), and was confirmed by liquid chromatography tandem mass spectrometry(LC-MS/MS). The limits of detection and quantification were $2.0{\mu}g/kg$ and $6.0{\mu}g/kg$, respectively. The recovery in the beans ranged from 82.2 to 98.4%. According to HPLC-FLD, zearalenone was detected in 13 samples (10.2% incidence), including 1 soybean and 12 red bean samples. The zearalenone contamination levels were in the range of 8.01${\sim}38.98{\mu}g/kg$. Finally, LC-MS/MS analysis was conducted in the contaminated samples to verify the results of HPLC-FLD. The LC-MS/MS results confirmed the presence of zearalenone in all 13 samples. The contamination level was lower than that of EU, which is below $100{\mu}g/kg$ for raw grains.

• Journal of Microbiology and Biotechnology
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• v.16 no.4
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• pp.643-646
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• 2006

Because of potential health hazards of aflatoxins for humans, the present study was conducted to monitor aflatoxin $B_1\;(AFB_1)$ in livestock feeds. A total of 249 samples of feeds collected in Korea were analyzed by DC-ELISA for qualitative analysis of $AFB_1$. Then, 27 samples that were verified to contain $AFB_1$ by DC-ELISA were quantitated by HPLC/FLD. HPLC/FLD analysis revealed that only one sample collected from a farm contained 11 ppb of $AFB_1$, whereas the other samples collected from feed companies did not contain $AFB_1$. The presence of $AFB_1$ was further confirmed by LC/MS analysis. TLC analysis indicated that the result of the DC-ELISA was most likely due to possible contamination of other mycotoxins rather than $AFB_1$. In conclusion, HPLC/FLD analysis following DC-ELISA is necessary for rapid and accurate detection of $AFB_1$.