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Volume 65, Issue 8
Special Articles : The First Papers of Prospective Analytical Chemists
Displaying 1-8 of 8 articles from this issue
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Research Papers
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Mai FURUKAWA, Hideyuki KATSUMATA, Tohru SUZUKI, Satoshi KANECOArticle type: Research Papers
2016 Volume 65 Issue 8 Pages 419-424
Published: August 05, 2016
Released on J-STAGE: September 06, 2016
JOURNAL FREE ACCESSThe developed method is a novel pre-concentration technique in which cadmium (Cd) is concentrated to activated carbon (AC) at the same time while sodium dodecyl sulfate (SDS) is modified to it by stirring. After the Cd species has been concentrated onto the sorbent, it is subsequently eluted by a nitric acid solution, followed by analysis with flame atomic absorption spectrometry (FAAS). The effect of the analytical parameters, such as the adsorption time, initial pH of the sample solution, type and volume of the eluent and interfering ions on the enrichment factor (EF) of Cd was optimized for the preconcentration. The formation of sodium dodecyl sulfate–loaded activated carbon (SDS/AC) was evaluated by scanning electron microscope (SEM), transmission electron microscope (TEM), fourier transform infrared spectrometry (FT-IR) and nitrogen adsorption/desorption isotherm (BET) methods. Little interference on the preconcentration of Cd by the matrix elements was observed in the present method. The detection limits (3S/N) were found to be 66 pg mL−1 for the Cd element. The relative standard deviation for a Cd solution (10 ng mL−1) was 3.1 % for ten measurements. The developed method was validated by the analysis of Cd ion in environmental samples.View full abstractDownload PDF (842K) -
Naoya TOMIYASU, Makoto NAMIKAWA, Hideji TANAKA, Masaki TAKEUCHIArticle type: Research Papers
2016 Volume 65 Issue 8 Pages 425-432
Published: August 05, 2016
Released on J-STAGE: September 06, 2016
JOURNAL FREE ACCESSThis paper describes a simultaneous analytical system used for atmospheric water-soluble acidic gases and anions in PM2.5. The analytical system, consisting mainly of a parallel-plate wet denuder, mist chamber−hydrophobic filter based particle collector, and ion chromatograph provides automatically two acidic gas and two PM2.5 data with in one hour. We applied the system to the continuous measurement of air pollutants at Tokushima, Japan in the winter of 2015, and obtained meaningful data in 97.9 % of the sampling period. The average acidic gas concentration and anion concentration in the PM2.5 were, respectively, 4.85±3.08 nmol m−3 for HCl, 22.19±18.47 nmol m−3 for HONO, 9.54±2.52 nmol m−3 for HNO3, 101.57±71.99 nmol m−3 for SO2, 3.78±6.48 nmol m−3 for Cl−, 3.37±1.99 nmol m−3 for NO2−, 25.16±31.49 nmol m−3 for NO3−, and 92.61±55.33 nmol m−3 for SO42−. Characteristic diurnal patterns were observed in several gases. The concentration of HCl fluctuated with changes in the temperature with a 2-hour time-lag. The concentration of HONO peaked in the morning and middle of the night, and its behavior showed a similar pattern of NO2 concentration. Backward trajectory analysis suggested that a high concentration of SO2 that was emitted from China was transported to the sampling site, Tokushima, Japan.View full abstractDownload PDF (954K) -
Masato SASAKI, Tokuo SHIMIZU, Nobuo UEHARAArticle type: Research Papers
2016 Volume 65 Issue 8 Pages 433-438
Published: August 05, 2016
Released on J-STAGE: September 06, 2016
JOURNAL FREE ACCESSA simple and selective method for the speciation of sub μg L−1 levels of inorganic chromium species in water samples is described. The proposed method is based on micro solvent extraction with an in situ extractant formation method using ethanol, and graphite furnace atomic absorption spectrometry. By mixing carbon disulfide and dioctylamine in ethanol prior to use, dioctyldithiocarbamic acid (DODC) forms. The extraction behaviors of Cr(III) and Cr(VI) into micro droplets, consist of unreacted carbon disulfide and dioctylamine, caused by a variation of the pH was investigated. At pH 3.0, Cr(VI) was selectively extracted from co-existing Cr(III) as a DODC complex after warming. At pH 6.5, both Cr(III) and Cr(VI) were simultaneously extracted as a DODC complex after warming. After the phase separation, the organic phases were dissolved into 500 μL of ethanol. A 20 μL aliquot of the diluted organic phase was injected into a graphite furnace treated by tungsten carbide. Under a 50-fold preconcentration factor by using 25 mL of water sample, a linear calibration curve of Cr(VI) was obtained over the range of 0 to 0.4 μg L−1 with a detection limit (3σ) of 4.9 ng L−1. Under a 40-fold preconcentration factor by using 20 mL of water sample, a linear calibration curve of total Cr [Cr(III)] was obtained over the range of 0 to 0.8 μg L−1 with a detection limit (3σ) of 11 ng L−1. The proposed method was successfully applied to river water samples.View full abstractDownload PDF (602K)
Technical Papers
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Ken-ichi SUGIE, Mamoru AKUTSU, Koichi SAITOArticle type: Technical Papers
2016 Volume 65 Issue 8 Pages 439-446
Published: August 05, 2016
Released on J-STAGE: September 06, 2016
JOURNAL FREE ACCESSIn recent years NPS abuse has become a serious social problem. To solve this problem the rapid analysis of drugs contained in NPS is required. In this study, a rapid and quantitative analysis that uses DART-TOF-MS was examined, in which a sample was injected directly into the ion source at atmospheric pressure. DART-TOF-MS with the conventional sample injection technique was not suitable for quantitative analysis because of the low reproducibility. Therefore, we developed a quantitative method with high-accuracy by introducing a micro syringe injection technique. Using α-PVP as the model compound and α-PBP as the internal standard, LOD was 0.03 μg mL−1, LOQ was 0.1 μg mL−1, and the calibration curve showed good linearity with the correlation coefficient of 0.999 in the range of 0.1 to 50 μg mL−1. α-PVP in liquid NPS was analyzed using the developed method and the conventional GC-MS method. The quantitative values obtained by the two methods were almost the same. On the basis of those results, the results suggest that the newly developed method enables simple, fast as well as high-accuracy quantitative analysis of α-PVP in liquid NPS.View full abstractDownload PDF (736K) -
Nobuhiko WADA, Tatsuo MORIMOTO, Shiroh TAKADA, Masanobu MORI, Hideyuki ...Article type: Technical Papers
2016 Volume 65 Issue 8 Pages 447-455
Published: August 05, 2016
Released on J-STAGE: September 06, 2016
JOURNAL FREE ACCESSWe describe the effect of a soil restoration material created using natural zeolite on the suppression of Cd uptake by agricultural crops in a Cd-contaminated farmland. The natural zeolite material (particle size < 1 mm), produced in the Kyushu area in Japan, demonstrates quantitative adsorption of Cd in test solutions. In this study, we prepared a restoration material consisting of the natural zeolite as a main metal-adsorbent, magnesia lime as a regulator of soil pH, and volcanic weathered clay to assist in homogeneously mixing them, for use in a test field. We refer to this prepared restoration material as a zeolite supplement. To determine the effect of applying this zeolite supplement on Cd uptake into crop, we performed tests in a double cropping farmland of rice and wheat for four consecutive years. Our results showed that Cd content was lower by 41 % and 86 %, respectively, in rice and wheat harvested from divisions where zeolite supplement was applied than the Cd content of crops in the control division where the zeolite supplement was not applied. Interestingly, the suppression of Cd uptake not only maintained for four years without further application of the zeolite supplement, but application of the supplement also resulted in the harvest of good quantities of rice and wheat. Thus, our study shows that this cultivation practice does not repeat application of large quantities of the supplement each year and is consequently a low-cost countermeasure for agricultural land contaminated with heavy metals.View full abstractDownload PDF (1117K) -
Yuma HIRANO, Yuki OHSHIMA, Masashi KOMATA, Naofumi OHTSUArticle type: Technical Papers
2016 Volume 65 Issue 8 Pages 457-463
Published: August 05, 2016
Released on J-STAGE: September 06, 2016
JOURNAL FREE ACCESSTo obtain accurate quantitative analytical results of Ag, Cu, and Ni in phosphate buffered saline (PBS) solutions by using graphite furnace atomic absorption spectrometry (GF-AAS), the effect of the PBS solution on the linear dynamic range and sensitivity were investigated in detail. For this purpose, the calibration curves of these metals in nitric acid (HNO3) and PBS solutions were constructed using both pyro-coated and uncoated graphite tubes. In the case of Ag, the sensitivity in the PBS with the pyro-coated tube was reduced by ca. 30 % against the HNO3 case, whereas such a reduction was not observed when using an uncoated tube. In the case of Cu, the sensitivity in the PBS was lower than that in the HNO3, regardless of the tube types. In the case of Ni, in contrast, a decrease in the sensitivity was hardly observed in both tubes. To determine the Ag, Cu and Ni concentrations exceeding their linear dynamic ranges, a sample solution should be measured after being diluted adequately. However, in the case of Ag in PBS, Ag chloride precipitates generated in the concentration range exceeding 400 μg L−1, lowered the analytical precision. Similarly, in the case of Cu in PBS, reductions of the accuracy and precision caused by the formation of Cu hydroxide precipitates were observed in the concentration range from approximately 200 to 500 μg L−1. Analysts should pay attention to the linear dynamic range and the sensitivity of GF-AAS in the quantitative analysis of Ag, Cu and Ni in a PBS. In addition, when analyzing these metals being out of the dynamic range, the solution should be diluted without the formation of precipitates and, otherwise, should be measured after decomposing the precipitates by a pretreatment.View full abstractDownload PDF (679K)
Notes
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Hideaki TOMITA, Noriaki SAMUKAWA, Mamiko ASANO, Takako YAMAGUCHI, Hito ...Article type: Notes
2016 Volume 65 Issue 8 Pages 465-470
Published: August 05, 2016
Released on J-STAGE: September 06, 2016
JOURNAL FREE ACCESSA novel spectrophotometric method was established for the determination of germanium(IV) and organogermanes. The method is based on ternary complex formation among germanium(IV), o-sulfophenylfluorone (SPF) and cetyltrimethylammonium chloride (CTAC). In the determination of germanium(IV), the absorbance at 530 nm obeyed Beer’s law in the range of 7.0−400 ng mL−1. The effective molar absorptivity at 530 nm and the relative standard deviation were 1.7 × 105 L mol−1 cm−1 and 0.96 % (n = 6), respectively. In the determination of propagermaniumu as organogermanes, the absorbance at 536 nm obeyed Beer’s law in the range of 30−1000 ng mL−1. The effective molar absorptivity at 536 nm and the relative standard deviation were 1.5 × 105 L mol−1 cm−1 and 1.13 % (n = 6), respectively. The recovery of germanium(IV) added to human urine was satisfactory being about 98 %. The proposed method requiring no solvent extraction should be useful for a simple and sensitive determinations of germanium(IV) and organogermanes.View full abstractDownload PDF (693K) -
Hiroki NAKAMURA, Shota MITANI, Makoto MOMOTANI, Mamiko ASANO, Takako Y ...Article type: Notes
2016 Volume 65 Issue 8 Pages 471-475
Published: August 05, 2016
Released on J-STAGE: September 06, 2016
JOURNAL FREE ACCESSSpectrophotometric determination of osmium(VIII) was accomplished with o-bromophenylfluorone (OBPF) in the presence of hexadecyltrimethylammonium chloride (CTAC). In the determination of osmium(VIII), Beer’s law was obeyed in the range of 0.02−1.4 μg mL−1, with an effective molar absorption coefficient (at 562 nm) and relative standard deviation of 1.22 × 105 L mol−1 cm−1 and 0.44 % (n = 10), respectively.View full abstractDownload PDF (650K)
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