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This study reports a new membrane filtration-based cleanup method for the analysis of pesticides. Recovery and cleanup by membrane filtration using 11 different membranes, classified by their molecular weight cut-off, pore size, and material, were examined. Three different eluent mixtures were also examined. The results indicated that membranes with a 0.1-μm pore size were the most effective among those tested. In particular, hydrophobic polyvinylidene difluoride and hydrophobic polytetrafluoroethylene gave better recoveries and cleanup than other membranes. Results from GC chromatograms and matrix effects showed that membrane filtration afforded better cleanup than the modified QuEChERS method. Furthermore, over 90% of the 89 pesticides tested had acceptable recoveries using these two membranes, according to an acceptable recovery range of 70–120%. Therefore, this technique has potential as an effective cleanup method.

The recovery and purification characteristics of membrane filtration for pesticide analysis of agricultural products were investigated. Eight different types of membranes classified by their molecular weight cut off (MWCO) and material were used. The results showed that the recovery and purification characteristics varied according to the eluting solvent used, as well as the membrane's MWCO and material. The recovery increased as the MWCO increased, and the purification increased when the eluting solvent contained water. A GK membrane with acetonitrile-water (1:1, v/v) was the most effective membrane filtration method among those tested. The pesticide analysis of spinach using the GK filtration method indicated that this method results in better purification than the modified QuEChERS method.

This research was conducted with the goal of clarifying the required conditions of water-saving showerheads. In order to this, the research analyzes the mutual relationship between water usage flow, the level of satisfaction and the physical properties of spray of showerheads. The physical properties of spray were measured using physical properties test apparatus of standard or scheme for water-saving showerheads issued in several water-saving countries, and satisfaction evaluation data was acquired through bathing experiments. The evaluated showerheads were separated into three groups according to usage water flow and the level of satisfaction. The relationships between usage water flow, the level of satisfaction and physical properties were compared. The results identified that Spray Force and Spray Force-per-Hole were physical properties that influence usage water flow. Spray force-per-hole, water volume ratio in Spray Patterns within φ 100 and φ 150, Temperature Drop and Spray Angle were identified as physical properties that influenced the level of satisfaction. The level of satisfaction and usage water flow has a spurious correlation through the physical properties of Spray Force-per-Hole and Temperature Drop. It is possible to improve the level of satisfaction independent of amount of water usage through designs that set an appropriate value for water volume ratio and Spray Angle for Spray Patterns within φ 100 and φ 150.

The purpose of this study was to construct a scheme that makes it possible to compare the relationship between water usage, satisfaction, and physical properties in three countries. The physical properties of the shower were measured using physical properties testing apparatus of water-saving standard or scheme for showerheads issued in several water-saving countries and data for users satisfaction evaluation was acquired through bathing experiments. In this paper, we analyzed the result from Taiwanese and Vietnamese individuals to compare them to of Japanese subjects analyzed in the previous study. We compared the physical properties of showers assessed low in satisfaction by Taiwanese, Vietnamese and Japanese subjects. It was assumed that spray pattern tends to decrease satisfaction when the water volume ratio within 100 mm and 150 mm of a measuring device is located a 450 mm distance from the showerhead is low, and that, because all three countries showed the same value, it was imagined that there were no differences in the water volume ratio of high-satisfaction showerheads among three countries. On the other hand, the values of Spray Force-per-Hole, Temperature Drop, and Spray Angle were different among three countries. We speculated that these differences are affected respectively by ethnic differences in pain tolerance, thermoregulatory response and bathing habit.