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Volume 62 (2008)
- Issue 6 Pages 258-
- Issue 5 Pages 234-
- Issue 4 Pages 179-
- Issue 3 Pages 128-
- Issue 2 Pages 72-
- Issue 1 Pages 3-
Volume 62, Issue 3
Displaying 1-6 of 6 articles from this issue
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Methylation in the Environment and Analysis Using GC/ICP-MSMichiko KURIHARA, Shinya HASHIMOTO2008 Volume 62 Issue 3 Pages 128-133
Published: 2008
Released on J-STAGE: February 19, 2013
JOURNAL FREE ACCESSIn the late 1960s, organotin compounds began to be used extensively as antifouling agents in marine paints because of their excellent antifouling properties. However, these compounds can adversely affect nontarget marine organisms; the leaching of organotin compounds from marine paints has caused extensive marine pollution. Although regulations have been enforced in most countries, organotins are still found throughout the world's oceans because of the long-term persistence of tributyltin (TBT) compounds in sediment and their diffusion from large vessels. In our study, trace levels of organotin compounds were found even in the Southern Ocean, approximately 1,000 km from Antarctica. Currently, highly sensitive analytical procedures including gas chromatography/inductively coupled plasma mass spectrometry (GC/ICP-MS) are used for the analysis of organotin compounds. GC/ICP-MS can detect organotin compounds in seawater at concentrations in the order of pg Sn/L and can detect trace organotin compounds such as tributylmonomethyltin (TBMMT). TBMMT, a volatile organotin compound that might be volatilized from seawater, is believed to originate from the degradation of TBT. TBMMT-to-TBT ratios show a positive correlation between sediment and bottom seawater, suggesting that TBMMT in seawater elutes from sediment. Furthermore, the major routes of decomposition of TBT in marine sediment seem to include not only debutylation but also methylation. The International Maritime Organization has approved a convention prohibiting the use of TBT in antifouling paints (entry into force: 17 Sep 2008). However, the fate of TBT in the marine environment should be monitored to ascertain the decrease in TBT levels after 2008, because TBT has long-term persistence and toxicity.View full abstractDownload PDF (4751K) -
Mitsuru HIGA, Megumi NISHIMURA2008 Volume 62 Issue 3 Pages 134-138
Published: 2008
Released on J-STAGE: February 19, 2013
JOURNAL FREE ACCESSThe concentration of fluoride and nitrate ions in ground water increases recently because of ground water mining and heavy usage of nitrogen fertilizers in agriculture, respectively. Excessive fluoride and nitrate ions in drinking water cause a multiplicity of ill effects for human health. Thus, removal of these ions from ground water is needed for improving the quality of drinking water. The concentration of bromide ion is one of the problems in salt producing process from the sea water. In order to improve the quality of drinking water and edible salts, development of an anion-exchange membrane that has high permselectivity between anions with the same sign and the same valence is needed. Permselectivity of specific anions through anion exchange membranes depends mainly on the balance of hydoration energy of anions with hydrophilicity of the membranes and partially on the balance of the hydrated ionic size of the anions with the degree of the cross-linking of the membranes. The permselectivity can be controlled by increasing cross-linkage of the membranes, by formation of tight surface layers on the membranes, and by changing the hydrophilicity of the anion-exchange groups and membrane matrix.View full abstractDownload PDF (3888K) -
Katsunari YAMAMOTO2008 Volume 62 Issue 3 Pages 139-147
Published: 2008
Released on J-STAGE: February 19, 2013
JOURNAL FREE ACCESSSalt is an essential material for mankind. Japan has been self-sufficient in terms of the supply of edible salt for domestic consumption since ancient times by concentrating and boiling down sea water. Nowadays most edible salt in Japan is made by means of the membrane concentration method, is a Japanese technology. The membrane concentration method eliminates virtually all marine pollutants and so is a very safe salt production method.
In 1997, the monopoly status of the salt industry in Japan was abolished, and the Salt Monopoly Law was replaced by the Salt Industry Law. In order to ensure a stable supply of high quality salt, production standards and check systems are needed on a voluntary basis.
The Japan Salt Industry Association, which is an organization of major edible salt manufacturers in Japan, established “The Safety and Sanitary Guidelines for Food Salt” to meet the deregulation and the diversification of supply source. The guidelines are in accordance with the Codex Standard for Food Grade Salt, HACCP and ISO22000, and then adapts to “the positive list system”, maximum residue limits for agricultural chemicals in foods.View full abstractDownload PDF (6896K) -
Yasushi NODA2008 Volume 62 Issue 3 Pages 148-151
Published: 2008
Released on J-STAGE: February 19, 2013
JOURNAL FREE ACCESSIn order to ensure the safety of edible salt, the Salt Industry Center of Japan has examined the basis of applying legal restrictions on the safety of food. Recently, a manufacturing standard, as one of the voluntary standards for ensuring safety of food has been established by this center. This manufacturing standard enables the verification that not only the product but also raw sea water and the manufacturing process are safe. In addition, we performed a study applying the CODEX standard, which is an international standard, to the specifications of salt, and we are also working on the correspondence of the Japanese Positive List System concerning residual agricultural chemicals in food.View full abstractDownload PDF (3159K) -
Hydrotalcite Like CompoundsTakayuki MURAKAMI, Kosuke ARAKAWA, Hisamitsu OHSHIMA, Tomoyuki KUWABAR ...2008 Volume 62 Issue 3 Pages 152-156
Published: 2008
Released on J-STAGE: February 19, 2013
JOURNAL FREE ACCESSThis paper discussed the adsorption and the removal capacity of Mg-Al Cl form hydrotalcite (HT) to fluorine and boron for solving the risk problem of fluorine and boron in the water environment and the resource problem of fluorine and boron at the same time.
The obtained results were as follows. HT rapidly adsorbed fluorine ion and borate ion at the anion concentrations of 1 to 10mg/L. The selectivity of HT for fluorine ion over borate ion is high. The removal mechanism of HT for fluorine ion was the ion exchange for chloride ion. And the removal mechanism of HT for borate ion was adsorption on aluminum hydroxide that dissolved from HT. These results showed that HT is an effective adsorbent to remove fluorine and borate ions in the waste water.View full abstractDownload PDF (3969K) -
Kyoko ISHIKAWA, Hiroyoshi SATO, Rie USAMI, Masanori KUMAGAI, Ryuji MAT ...2008 Volume 62 Issue 3 Pages 157-162
Published: 2008
Released on J-STAGE: February 19, 2013
JOURNAL FREE ACCESSFor four samples of salt that were produced using different processes and which had different contents of inorganic components, we used a sensory evaluation to study their respective effects on the tastes of four foods: lemon water, rice gruel, sweet bean-paste soup, and asazuke of turnip. The sourness of lemon water was influenced by differences in inorganic components among salt samples. The different inorganic components among salt samples affected the saltiness of rice gruel. A salt sample with high concentration of bittern components weakened the saltiness. The addition of salt samples enhanced the sweetness of sweet bean-paste soup, but differences among salt samples were not observed. For asazuke, the bittern components did not affect the saltiness, but enhanced other tastes such as bitterness. These results suggest that inorganic components in commercial salts strongly affect food tastes.View full abstractDownload PDF (4544K)
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