Abstract This report describes the application of LC-MS/MS for the separation of dodecanol (C12OH) and homogenous fatty alcohols ethoxylated (AE) containing a dodecyl moiety and 1-9 ethoxy groups. These ethoxylates and free alcohol were derivatized for LC-MS/MS analysis with phenyl isocyanate (PIC). The derivatives of analytes with PIC were separated using a C18 column. Gradient elution with a ...

A powerful chromatographic method coupled to a fluorescence detector was developed to determine the phenolic compounds present in virgin olive oil (VOO), with the aim to propose an appropriate alternative to liquid chromatography-mass spectrometry. An excitation wavelength of 285 nm was selected and four different emission wavelengths (316, 328, 350 and 450 nm) were simultaneously recorded, wor...

Unlike most other bees, the long-tongued orchid bees ingest nectar using suction feeding. Although long tongues allow exploitation of flowers with deep spurs, the energy intake rate is optimal at 10-20% lower nectar sugar concentrations compared to that of lapping bees. This constraint might be compensated by a higher digestive throughput. Additionally, orchid bees might evaporate water from re...

Although pathogens such as nematodes are known to hijack nutrients from host plants, the mechanisms whereby nematodes obtain sugars from plants remain largely unknown. To determine the effects of nematode infection on host plant sugar allocation, soluble sugar (fructose, glucose, sucrose) content was investigated using high-performance liquid chromatography with refractive index detection and w...

BACKGROUND AND AIMS Variation in the composition of floral nectar reflects intrinsic plant characteristics as well as the action of extrinsic factors. Micro-organisms, particularly yeasts, represent one extrinsic factor that inhabit the nectar of animal-pollinated flowers worldwide. In this study a 'microbial imprint hypothesis' is formulated and tested, in which it is proposed that natural com...

Abstract. Fadhilla S, Hakim L, Agustian A, Lubis YS, Siregar AW. 2022. The diversity of utilizations, tapping flow discharge, and conservation sugar palm (Arenga longipes Mogea) cultivated in Langkat, North Sumatra, Indonesia. Biodiversitas 23: 122-132. Sugar is one the Non-Timber Forest Products (NTFPs) by forest community village Sei Limbat, Selesai Sub-district, Langkat District, Sumatra. It...

The common phenomenon of buoyancy-induced vapor bubble lift-off from a heated surface is of importance to many areas of science and technology. In the absence of buoyancy in zero gravity of space, non-departing bubbles coalesce to form a big dry patch on the heated surface and heat transfer deteriorates despite the high latent heat of vaporization of water. The situation is worse on an inverted...

In this paper, we have investigated the dielectric properties of nematic liquid crystals (NLCs) by measuring resonant frequencies inverted microstrip lines (IMSLs) NLC being substrate material at microwave frequency band. The designed IMSL devices consist a cavity for mixture between line and ground plane. anisotropy values NLCs were determined observing change when strength external electric f...

Until recently glucose was the only sugar used for intravenous administration. Glucose was indeed the obvious choice, for it is constantly present in the blood and it also occupies a central position in carbohydrate metabolism. The results obtained by the intravenous administration of glucose are satisfactory. However, if glucose in a higher concentration than 500 is used difficulties may ensue...

In three different phase-separated binary liquid mixtures we have observed stationary capillary rises in which the meniscus curvature is inconsistent with the sign of the rise. This ‘‘inverted-meniscus’’ configuration occurs within approximately 50 mK of the mixture’s critical temperature and shows no sign of decay after much longer than the characteristic time for relaxation. We also report ex...