Search

Destructive identification of ballpoint pen ink was performed using field desorption mass spectrometry (FDMS) to determine the basic dyes in ballpoint pen ink. Seven different brands of black, blue, and red ballpoint pen inks (total: 21 samples) were examined in this study. A 1-mm section was cut from an ink line drawn on paper and used as the sample. Extraction was performed with methanol. Analysis of each extract by FDMS showed the molecular ion peak of each dye and the black, blue, and red inks were then classified into 6, 6, and 6 types, respectively, based on the ions detected. The results indicated that it was possible to distinguish between manufacturers of ballpoint pens. This analysis of ballpoint pen inks was found to be effective and the method was applied to the analysis of an actual forensic sample.

We investigated the effects of morphological characteristics of cucumber, Cucumis sativus L., seedlings grown at different vapor pressure deficits (VPDs) on initial colonization of whitefly Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) biotype B. The seedlings were grown at a VPD of 3.8 or 0.4 kPa for 9 d at 30°C under a photoperiod of 12:12 (L:D) h. Pairs of seedlings, one grown at high VPD and the other at low VPD, were then installed in cages with a VPD of 1.3 kPa, and adults of B. tabaci between 150 and 200 were released. Leaves of high-VPD seedlings had fewer B. tabaci than those of low-VPD seedlings 24 h after release. They also had higher relative chlorophyll content, were thicker and tougher, and had abaxial trichomes with higher density. Water stress caused by the high VPD probably decreased the initial colonization of B. tabaci through changes in these leaf morphological characteristics.