Abstract. Citrus is one of the most important agricultural crop in Florida. Heavy reliance on agricultural chemicals and low fertilizer efficiencies have raised environmental and economic concerns. In this study, a system to sense nitrogen levels in a single citrus leaf was developed. Based on chlorophyll and protein spectral absorption bands, the sensing system’s wavelength ranges were chosen ...

The aim of this work was to compare determination of quercetin concentration using HPLCUV/VIS method with antioxidant properties of selected red wines. Typical Slovenian wine varieties like “Merlot”, “Refošk”, “Barbera”, “Cabernet Sauvignon”, “Teran”, “Blue Pinot” and “Blue Frankish” were chosen. We applied the conventional Folin-Ciocalteu spectrophotometric method for determination of the tota...

Fenarimol (Rubigan) is a pyrimidine ergosterol biosynthesis inhibitor used as a systemic fungicide. The authors present a fatal fenarimol intoxication case analysed in the Forensic Toxicology Service of the National Institute of Legal Medicine. The results were used to compare two different HPLC techniques, regarding selectivity and sensitivity: an HPLC system with a diode array detector (DAD) ...

Eight vegetables were pre-treated with and without sa­ ponification, and chromatographed by reversed-phase HPLC. Carote11Oid peaks were identified using seven reference standards. Samples extracts were also chromatographed llsing a mixed magnesia and diatomaceous earth column. Fractions were eluted using stepwise increases in the proportion of acetone in hexane, studied by UV-VIS ab­ sorption s...

Even in the early times of chromatography with conventional detectors (i.e. UV/VIS, FID) it became evident that different sample matrices present peculiar interfering compounds, and the importance of using appropriate spiked matrix calibrators in order to get reliable quanti‐ tative results was recognized. In these conditions, however, the main concern was the presence of coeluting compounds gi...

Remote-sensing platforms are often comprised of a cluster of different spectral range detectors or sensors to benefit from the spectral identification capabilities of each range. Missing data from these platforms, caused by problematic weather conditions, such as clouds, sensor failure, low temporal coverage or a narrow field of view (FOV), is one of the problems preventing proper monitoring of...

Table 1: Common detector materials and their typical detection range within the VIS-IR wavelength regions. Above 1100nm, Silicon is transparent and therefore cannot be used to detect photons of these wavelengths, however many other materials do have photon sensitivity at these wavelengths and longer, see Table 1. The materials listed have been developed into detection systems which enable image...

background black pepper (piper nigrum) is one of the well-known spices extensively used worldwide especially in india, and southeast asia. the presence of alkaloids in the pepper, namely, piperine and its three stereoisomers, isopiperine, chavicine and isochavicine are well noticed. objectives the current study evaluated the effect of lyophilization and oven drying on the stability and decompos...

The analysis of carotinoids is usually performed by HPLC with UV/VIS detection. Different geometric isomers can be separated using C30 stationary phases [1]. However, the complexity of most matrices makes an unequivocal identification very difficult. For this reason we investigated the use of an ion trap analyzer for the identification of carotinoids in spinach. Since carotinoids are rather non...