A dehydrated space-weathered skin cloaking the hydrated interior of Ryugu

Without a protective atmosphere, space-exposed surfaces of airless Solar System bodies gradually experience an alteration in composition, structure and optical properties through a collective process called space weathering. The return of samples from near-Earth asteroid (162173) Ryugu by Hayabusa2 provides the first opportunity for laboratory study of space-weathering signatures on the most abundant type of inner solar system body: a C-type asteroid, composed of materials largely unchanged since the formation of the Solar System. Weathered Ryugu grains show areas of surface amorphization and partial melting of phyllosilicates, in which reduction from Fe3+ to Fe2+ and dehydration developed. Space weathering probably contributed to dehydration by dehydroxylation of Ryugu surface phyllosilicates that had already lost interlayer water molecules and to weakening of the 2.7 µm hydroxyl (–OH) band in reflectance spectra. For C-type asteroids in general, this indicates that a weak 2.7 µm band can signify space-weathering-induced surface dehydration, rather than bulk volatile loss

Determination of Alpha-and Beta-cryptoxanthins, and Alpa-and Beta Carotenes in Buah Merah Oil by HPLC-UV Detection

A high-performance liquid chromatography-UV detection method for determination of Alpha-and Beta-cryptoxanthins and, Alpha-and Beta-carotenes in Buah Merah oil was developed. The separation of the four carotenoids was achieved by a combination of a Handy ODS column (150x4.6 mm, i.d.) and a Develosil Combi-RP-5 (50x4.6 mm, i.d.) via a 3-port switching valve. The mobile phase used was a mixture of CH3CN/CH3OH/ethyl acetate (=68:23:9, v/v/v). The retention times of Alpha-and Beta-cryptoxanthins and, Alpha and Beta-carotenes were 18, 20 53 and 60 min, respectively. The clean-up of Buah Merah oil was performed by liquid-liquid extraction after saponification with 13.5 M KOH solution. The calibration curves of the carotenoids showed good linearity (r> 0.000. The detection limits of four carotenoids at a signal-to noise of 3 were from 0.36 to1.14 ng/mg. Furthermore, the proposed method could be successfully applied to determine the carotenoids in 10 Buah Merah oil samples