Simultane Thermische Analyse an Gro\en Proben

The investigation of wastes, pollutants, contaminated soil, etc. in preparation of their thermal disposal or decontamination is related to several problems. Due to the heterogeneity of the sample materials, thermoanalytical measurements, using standard sample amounts of about 20–50 mg do not lead to reliable results. For this reason, a new thermoanalytical device for about 100 g sample amount was developed. The Macro STA 419, was constructed and built for simultaneous TG- and DTA-investigations with direct coupled measuring techniques for gas analysis (MS/GC-MS). The new developed device is introduced, some problems and their solutions are discussed and the function of the device is shown.

     

Investigation of the complex thermal behavior of fats

The thermal behavior of three ural fats (displaying very different composition), cocoa butter (CB)², lard, and a stearin obtained from anhydrous milk-fat (AMF) fractionation, were studied by both DSC and X-ray diffraction as a function of temperature (XRDT). To perform temperature explorations between –30C and +80C, at rates identical to those used for DSC and ranging from 0.1 K min^–1 to 10 K min^–1, a new set of X-ray sample-holders, temperature-controlled by Peltier effect, has been developed. It is shown that the three more stable polymorphic forms of CB were easily characterized by either X-ray diffraction or DSC, and existence of two -3L forms was confirmed. On the contrary, the more complex polymorphism of lard and AMF required combined examination by DSC and XRDT and the brightness of the synchrotron source for studies at the highest heating rates. Quantitative analysis of the long spacings of XRDT recordings is invaluable for interpretation of thermal events. For instance, it was found that the simultaneous formation of two polymorphic forms, of apparent long spacing of 34 and 42 å, at the onset of lard crystallization might explain the difficulty of its fractionation.Special thanks to Courtney P. Mudd (NIH, Bethesda) for his pertinent advice on the mounting and use of thermoelectric devices. The study of lard crystallization was initiated by Valerie Portalier and suggested by Jean-Luc Vendeuvre of CTSCCV (Maisons-Alfort). For the AMF part of this study, stearin was fractionated by ADRIA Normandie, while characterization of its thermal properties was performed as part of a research program funded by ARILAIT Recherches and the French Ministry of Research and Technology.     

Comparison of different extraction techniques for the determination of chlorinated pesticides in animal feed

The performances of Soxhlet extraction, dive-in Soxhlet extraction, microwave-assisted extraction (MAE), accelerated solvent extraction (ASE), fluidized-bed extraction (FBE), and ultrasonic extraction (UE) for the analysis of organochlorine pesticides in animal feed have been investigated. ASE and MAE provided significantly better extraction efficiency than Soxhlet extraction. The concentrations were 126.7 and 114.8%, respectively, of the values obtained by classical Soxhlet extraction, whereas the results from FBE and dive-in Soxhlet were comparable with those from the standard Soxhlet procedure. The reproducibility of FBE was the best, with RSDs ranging from 0.3 to 3.9%. Under the investigated operation conditions UE was not efficient, with the recoveries of target compounds being about 50% less than Soxhlet. Additionally, the performances of Soxhlet, dive-in Soxhlet, MAE, ASE and FBE were validated by determination of the certified reference material BCR-115. The results from the extraction techniques were in good agreement with the certified values.     

Precise and accurate determination of lead isotope ratios in mining wastes by ICP-QMS as a tool to identify their source

A methodology for a precise and accurate determination of lead isotope ratios in mining wastes by inductively coupled plasma quadrupole-based mass spectrometry (ICP-QMS) has been developed. The study of instrumental bias factors led to the conclusion that internal correction to compensate mass discrimination is required as well as an interference equation correction when Hg is present. The proposed method has been applied to determine lead isotope ratios in several mining wastes, soils and sediments collected at three mining areas in Spain (Aran Valley, Cartagena and Osor).Statistical analysis highlights that ²⁰⁶Pb/²⁰⁷Pb and ²⁰⁸Pb/²⁰⁷Pb lead isotope ratios can be used as a fingerprint of mining waste origin which is related to the geological age of the lead ore.On the other hand, no statistically significant isotopic differences between original ore samples (galena) and processing wastes within a mining district were found, corroborating a unique lead source. Moreover, the lead isotopic composition of soil and sediment samples collected at the studied mining areas is close to that determined in the mining tailings from the same areas, suggesting that the unusual high content of lead in these samples is derived from mining activities rather than from other lead sources.     

棕腹刺河豚肌肉中三大营养成分的研究

采用国标方法测定了棕腹刺河豚肌肉中三大营养成分.结果表明,棕腹刺河豚肌肉的可食部87.30%;每100 g可食部中水分78.50 g,蛋白质19.30 g,脂肪1.94 g,碳水化合物0.26 g,热量95.70 kcal（1 cal=4.1868 J）.同法测定了黑鳃兔头豚肌肉的营养成分,结果表明,可食部66.14%;每100 g可食部中水分80.18 g,蛋白质18.70 g,脂肪0.68 g,碳水化合物0.25 g,热量81.92 kcal.两种河豚均在珠江口捕获.综合来看,棕腹刺河豚可食部、蛋白质、脂肪、碳水化合物、热量等均比黑鳃兔头豚高,且安全食用[1].据此认为,棕腹刺河豚为良好的蛋白质和脂肪资源,建议在秋冬季节捕捞和开发棕腹刺河豚.     

复方有机锗兽用保健促长剂的研究和开发应用

复方有机锗（Ｇｅ－１３２）兽用保健促长剂（肥猪宝）是将有机锗（Ｇｅ－１３２）创造性地应用在动物饲养上，在总结国内外先进专利技术基础上，经反复实验，开发出新一代动物保健型促长剂。具有增强免疫功能，促进细胞分裂及组织生长等作用，且不同于传统添加剂多数含抗生素，维生素及动物激素等。其特点是抗病防病能力强，生长迅速，肉料比高，且能防治生猪腹泻。本产品经四家养猪场对照实验，效果显著，日平均多增重１９３克比国     

Tannery trimming waste based biodegradable bioplastic: Facile synthesis and characterization of properties

In the present research, the untanned proteinaceous trimming waste from tanneries was used to prepare highly flexible and transparent bioplastic films. Composite bioplastic films were fabricated by blending trimming hydrolysate powder and polyvinyl alcohol using the solution casting method. In addition, a non-toxic and relatively inexpensive bio-crosslinker – citric acid was used as a plasticizer/crosslinking agent. The effects of citric acid concentration on the mechanical properties, thermal stability, transparency and anti-microbial properties of the bioplastic films were investigated. Crosslinking interactions by the citric acid on the constituents of the bioplastic were confirmed using FTIR/ATR. Also, the surface microstructure of the films was studied using SEM. The resultant bioplastic films were smooth, uniform and defect-free. Citric acid used in the bioplastic blend formulation clearly acted as a plasticizer at higher concentrations. The trimming waste-based bioplastic with the citric acid concentration of 40% exhibited an outstanding tensile strength above 20 MPa and extremely high elongation at break value greater than 343%. The bioplastic degraded to an extent of 62% within 70 days under the soil burial test. The transparency of the bioplastics was comparable with the LDPE and PP-like conventional plastics. The anti-microbial properties of the films are the positive aspects brought about by the presence of citric acid interactions. Consequently, trimming based bioplastics may become a future friendly alternative to fossil derived plastics having applicability in packaging, wound healing and other biocompatible applications.     

Characterization of Wastes from Olive and Sugarbeet Processing Industries and Effects of Their Application upon the Organic Fraction of Agricultural Soils

Abstract

The lipidic fraction compositions of both concentrated vinasses, a by-product of the sugar industry, and a compost made basically from olive oil vegetation waters (alpechin) were studied. The alpechin lipids are composed mainly by series of n-alkanes and lineal and branched fatty acids, whereas the major lipids in vinasses were n-alkanes, n-alkanols and acetals. Concentrations and composition of lipids in both materials do not seem of concern.

Preliminary results on the effects of the application of both materials over two years on the organic status of an agricultural soil are also reported. No significant changes were observed in total organic carbon and contents in humic fractions and lipids before and after the applications. However, analysis by GC-MS of the lipid compounds present in bound forms in the subsoil layer revealed that some hydrophobic components were accumulated in the soil following the waste applications.     

High-throughput non-destructive nuclear magnetic resonance method to measure intramuscular fat content in beef

High intake of saturated fat from meats has been associated with cardiovascular disease, cancer, diabetes, and others diseases. In this paper, we are introducing a simple, high-throughput, and non-destructive low-resolution nuclear magnetic resonance method that has the potential to analyze the intramuscular fat content (IMF) in more than 1,000 beef portions per hour. The results can be used in nutritional fact labels, replacing the currently used average value. The method is based on longitudinal (T ₁) and transverse (T ₂) relaxation time information obtained by a continuous wave-free precession (CWFP) sequence. CWFP yields a higher correlation coefficient (r = 0.9) than the conventional Carr-Purcell-Meiboom-Gill (CPMG) method (r = −0.25) for IMF in beef and is just as fast and a simpler pulse sequence than CPMG. The method can also be applied to other meat products.     

Development and validation of a liquid chromatography tandem mass spectrometry method for the analysis of β-agonists in animal feed and drinking water

A reproducible, sensitive and selective multiresidue analytical method for seven β-agonists: clenbuterol (CBT), clenpenterol (CPT), ractopamine (RTP), brombuterol (BBT), mabuterol (MBT), mapenterol (MPT), and hydroxymethylclenbuterol (HMCBT) was developed and validated by using liquid chromatography tandem mass spectrometry (LC–MS/MS) in feed and drinking water samples. The validation was achieved according to the criteria laid down in the Commission Decision 2002/657/EC, however it was necessary to use minimum required performance limits (MRPLs) proposed by the Community Reference Laboratories (CRLs) due to the lack of maximum residue limits (MRLs) for β-agonists. By setting up these MRPLs, allows controlling their use in safe mode, since β-agonists are commonly used in veterinary medicine sometime in a fraudulent manner, for increasing the weigh of animals. Values set for both matrices studied are 50 μg/kg for animal feed, and a range from 0.2 to 10 μg/L for drinking water. CCα values calculated were under the MRPLs suggested; for drinking water the lowest value obtained was 0.12 μg/L, and for animal feed 0.87 μg/kg. Values for CCβ were ranged from 0.08 to 0.13 μg/L in drinking water and from 0.5 to 0.92 μg/kg in animal feed samples. The excellence values obtained, allowed us to conclude that the proposed analytical method is capable to control the β-agonists studied in both matrices and that it can be successfully applied and used as a routine method in laboratories of residue analysis of veterinary food control.