MANAGAKI SATOSHI

In the present study, the dehydration process of caffeine hydrate (CAH) was investigated by calibrating the moisture content in the caffeine tablet using backscattering Raman spectroscopy (BRS) and transmission Raman spectroscopy (TRS). The detectable depth of BRS is limited by its shallow laser penetration, while TRS is a powerful tool to determine the content of active pharmaceutical ingredients in a tablet. Our results suggest that the accuracy of a TRS-based calibration model falls beyond that of a BRS-based model. Based on the calibration used, the model was built by calculating the differences in the crystalline structures between hydrate and anhydrous caffeine. Moreover, it was demonstrated that the dehydration process occurred by switching water molecules between hydration sites of caffeine. (C) 2017 Elsevier B.V. All rights reserved.

Hexabromocyclododecane (HBCD) and its lower brominated derivatives were measured in both surface water and sediment samples from three Japanese rivers; Tsurumi River, Yodo River, and Kuzuryu River. The concentration level of Sigma HBCD (sum of alpha-, beta-, and gamma-HBCD) was in the order of Kuzuryu > Yodo > Tsurumi Rivers, reflective of the different emission sources for each basin. The highest Sigma HBCD concentration (7800 ng g(-1)) was detected in the sediment sample from the Kuzuryu River that receives effluents from textile industries, which use HBCD in flame retardant finishes. A different diastereomeric pattern of alpha-, beta-, and gamma-HBCD of each river was investigated, indicating the level of HBCD in these rivers is directly influenced by emission source. Enantiomer fractions of HBCDs in water and sediment samples were also determined. Racemic mixtures were observed in the water samples, whereas enantiomeric enrichment of (-) gamma-HBCD and (+) alpha-HBCD was observed in the sediment samples. Some lower brominated HBCD derivatives such as pentabromocyclododecenes were detected in both the water and sediment samples, and their concentration ranged from below the detection limit to 15 ng L-1 and 20 ng g(-1) dw, respectively. (C) 2014 Elsevier Ltd. All rights reserved.

Perfluorooctane sulfonate (PFOS) was quantified in seawater and sediment samples collected from Tokyo Bay, Japan, ranging from 2.0 to 7.3ng/L for surface seawater, 2.2 to 5.7ng/L for intermediate seawater, 1.5 to 5.7ng/L for bottom seawater, and 0.3 to 0.9ng/g dry wt. for sediment. In addition, a 3-D chemical fate prediction model (National Institute of Advanced Industrial Science and Technology - Risk Assessment Model: AIST-RAM) has been applied to determine the accuracy of estimating PFOS in Tokyo Bay. A decreasing trend of PFOS from the northwestern part (i.e., the closed-off section of Tokyo Bay) to the mouth of the bay was observed, and the trend obtained from the actual surveys in this study was accurately represented by simulation with appropriate input parameters for AIST-RAM. From the comparison of observed concentrations with estimated concentrations, AIST-RAM showed a high degree of accuracy in estimating the concentrations of PFOS in seawater, whereas the estimations of PFOS concentrations in sediment had a relatively larger margin of error than those in seawater. However, our results indicate that AIST-RAM allows estimation of PFOS concentrations in seawater and sediment in Tokyo Bay with satisfactory accuracy.

Persistence and dispersal of antibiotic resistance genes (ARGs) are important factors for assessing ARG risk in aquaculture environments. Here, we quantitatively detected ARGs for sulphonamides (sul1 and sul2) and trimethoprim (dfrA1) and an integrase gene for a class 1 integron (intI1) at aquaculture facilities in the northern Baltic Sea, Finland. The ARGs persisted in sediments below fish farms at very low antibiotic concentrations during the 6-year observation period from 2006 to 2012. Although the ARGs persisted in the farm sediments, they were less prevalent in the surrounding sediments. The copy numbers between the sul1 and intI1 genes were significantly correlated suggesting that class 1 integrons may play a role in the prevalence of sul1 in the farm sediments through horizontal gene transfer. In conclusion, the presence of ARGs may limit the effectiveness of antibiotics in treating fish illnesses, thereby causing a potential risk to the aquaculture industry. However, the restricted presence of ARGs at the farms is unlikely to cause serious effects in the northern Baltic Sea sediment environments around the farms.