Different extraction approaches for the biomonitoring of pesticides in pine needles.

An ultrasonic extraction (USE) procedure followed by two alternative clean-up approaches using solid-phase extraction (SPE) cartridges (ENVI 18 and Florisil) and QuEChERS extraction and clean-up methodology were tested and compared for the determination of20 pesticides in Pinus pinea needles. The analysis and quantification were performed by gas chromatography-mass spectrometry (GC-MS) in selected ion storage (SIS) mode, using triphenyl phosphate (TPP) as the internal standard. One sample mass (5 g) and two pesticide spiking levels (20 and 100 ng g(-1)) were used in the validation assays. The limits of detection (LODs) were lower than 15.96 ng g(-1) for ENVI 18, 11.36 ng g(-1) for Florisil and 16.67 ng g(-1) for QuEChERS. Florisil yielded higher coefficients of variation for replicated analysis as did QuEChERS for the intermediate precision. To test pine needles' capacity as biomonitors for these pesticides, naturally contaminated needle samples were analyzed. With a 34% overall detection rate, concentrations ranged from 0.10 to 17.73 ng g(-1) (dry weight). USE + ENVI 18 and USE + Florisil were overall the best options for pesticide assessment in pine needles.

Nephrotic syndrome due to minimal change disease secondary to spider bite: clinico-pathological case of a non-described complication of latrodectism.

The patient was an 18-year-old man who developed nephrotic syndrome after a 'wheat spider' bite (Latrodectus mactans). Due to this atypical manifestation of latrodectism, a renal biopsy was performed showing minimal change disease. The nephrotic syndrome subsided after 1 week without specific treatment. This self-limited evolution suggests that the mechanism of podocyte damage was temporary and potentially mediated by a secondary mechanism of hypersensitivity or direct effect of the α-latrotoxin. The patient did not show signs of relapse in subsequent checkup. This is the first reported case of nephrotic syndrome due to a minimal change lesion secondary to latrodectism.

Analysis of organic acids in wines by Fourier-transform infrared spectroscopy.

Fourier-transform infrared (FTIR) spectroscopy has been a major point of development in many wine laboratories in recent years. It enables almost instant analysis of several properties of wine, usually with very good precision and accurate results. Nevertheless, validation procedures should not be forgotten and should be fully performed. Recovery experiments were performed by spiking wine samples with different amounts of organic acids (tartaric, malic, lactic, acetic and citric--the most prominent in wines). After FTIR analysis of the total acidity and of each organic acid concentration, recoveries were calculated. For total acidity recovery results were, in general, good and very close to 100% (64-111%). On the other hand, for individual organic acid concentrations, the recovery results were lower than 100% (11-73%) for all spiking additions. These results could be explained by spectroscopic interferences between the organic acids. Because they have similar infrared spectra, it is not easy to distinguish between them and, therefore, to achieve accurate calibration. When total acidity, with a different infrared spectrum from the other abundant compounds in the wine, was taken as a single property the recovery results were acceptable.