肥料中硫检测方案(快速溶剂萃取)

智能文字提取功能测试中

APPLICATION NOTEF&F-S-002-2018/A1 SULPHUR DETERMINATION IN FERTILIZERRANDALL METHOD Sulphur Determination in Fertilizeraccording to the Randall method Tested with VELP Scientifica SER 158/6 Solvent Auto Extractor (Code S303A0380) Introduction Sulphur is one of the 17 essential plant nutrients. It is essential for the growth and development of all crops， withoutexception. Like any essential nutrient， sulphur also has some key functions in plants： Formation of chlorophyll that permits photosynthesis through which plants produce starch， sugars， oils， fats，vitamins and other compounds. Protein production. Sulphur is a constituent of three S-containing amino acids (cysteine， cystine andmethionine)， which are the building blocks of protein. About 90% of plant S is present in these amino acids. Synthesis of oils. This is why adequate sulphur is so crucial for oilseeds. Activation of enzymes， which aid in biochemical reactions in the plant. Increases crop yields and improves produce quality， both of which determine the market price a farmer wouldget for his produce. With reference to crop quality， S improves protein and oil percentage in seeds， cereal quality for milling and baking， marketability of dry coconut kernel (copra)， quality of tobacco， nutritive value of forages， etc. It is associated with special metabolisms in plant and the structural characteristics of protoplasm. For all these reasons it is very important to monitor and if necessary increase the amount of sulfur in the soil usingappropriate fertilizers. Gravimetric Sulphur Determination in Fertilizer Hot solvent extraction process with SER 158 Series can be summed up in 5 steps， for a fully unattended operation： During IMMERSION the sample is immersed in boiling solvent. Then the REMOVING step automatically lowers the levelof the solvent to below the extraction thimble. During WASHING the condensed solvent flows over the sample andthrough the thimble to complete the extraction process. The fourth step involves solvent RECOVERY. Approximately90% of the solvent used is collected in the internal recovery tank. The final step is the COOLING of the extraction cupscontaining the extracted matter. The extraction cups containing the extract are placed in a drying oven， cooled in adesiccator and weighed for the extract percentage calculation. Sample Fertilizer Expected Sulphur： 42.0 ±0，5% Chemicals and Equipment Required Analytical balance， 3 decimals Extraction thimbles 33x80 mm (Code A00000295) Glass extraction cups 056x120mm (Code A00000290) Vaflon seals (Code A00000288) ● Dichloromethane (DCM) as solvent Fan convection oven ● Dessiccator Sample Preparation In order to obtain reliable and repeatable results it is necessary to homogenize the sample before starting the analysis.Fix every Extraction thimbles with the Extraction thimbles holders (Code A00000312). Weigh 2.5g of sample directly inthe VELP extraction thimbles using the Thimble weighing cup (Code A00000310) (the quantity of sample weighed islinked to the percentage of sulfur to be extracted). Glass Extraction Cups Preparation Position the empty extraction cups in an drying oven (105°C) for 1 hour. Cool them in a desiccator until constant weight of the tare (Tare). The extraction cups containing the extraction thimble con now be placed on the ultra-fast heating plate of SER158. Extraction Procedure with SER 158 On the ControlPad select“Analysis”， and then create a new method setting the following parameters： ●· Immersion Time： 60 minutes ·Cooling Time： 4 minutes ●Removing Time： 10 minutes ·Solvent： Dichloromethane (*)， 100 ml●Washing Time： 180 minutes Extraction cups： Standard 056x120mm Recovery Time 20 minutes Thimble：33x80 mm (*)Dichloromethane requires the energy level 4 and the Vaflon seals (Code No. A00000288)， please select them in theappropriate customized solvent menu. Close the safety guard and add the solvent using the automatic solvent dispensing system SolventXpress TM to minimizeexposure to the solvent ensuring operator safety. Press START to begin the extraction process. At the end of analysis position the extraction cups containing the extractin a drying oven (1 hour at 105C)， cooled them in a desiccator to room temperature and record the accurate weight(Total). Typical Results on Fertilizer Analysis results are calculated automatically and stored in the ControlPad when entering the weights into the software(manually or automatically through a balance). The extract percentage calculation is performed by using the followingformulas： Extract (%)=Extract x 100/(Sample) Where： Sample = sample weight (g) Tare= weight of the empty extraction cup (g) Total = weight of the extraction cup +extract (g) Sample (g) Extract (g) Extract (%) 2，501 1，0459 41，82% 2，501 1，0463 41，83% 2，501 1，0457 41，81% 2，502 1，0461 41，82% 2，501 1，0460 41，82% 2，505 1，0476 41，82% Average ±SD% 41.82±0.01 RSD% ** 0.02 Expected Sulphur： 42.0±0，5% *RSD%=(Standard Deviation x 100)/ Average Conclusion The results obtained are reliable and reproducible in accordance with the expected values， with a low relative standarddeviation (RSD<1%)， that means high repeatability of the results. The SER 158 Solvent Extractor is the ideal solution for environmental analysis such as the determination of Sulphur infertilizer samples. The Benefits of hot solvent extraction (Randall) by using 158 Automatic Solvent Extractor are： - up to 5 times faster than Soxhlet (hot solvent vs. cold solvent) -low solvent consumption (high solvent recovery， approximately 90%) - limited cost per analysis -no exposure to solvent -worldwide official method - full traceability with automatic result calculation and on-board archive Copyright C VELP Scientifica. All rights reserved.No part of this publication may be reproduced or transmitted in any form or for any purpose without the express permission of VELP.VELP Scientifica， Italy Tel： + Fax： + www.velp.com 利用SER158全自动溶剂萃取仪分析肥料中的硫含量:硫是植物必需的17种营养素之一。毫无疑问，这对于所有农作物的生长和发育至关重要。像任何必需营养素一样，硫在植物中也具有一些关键功能：-允许光合作用的叶绿素的形成，植物通过该叶绿素产生淀粉，糖，油，脂肪，维生素和其他化合物。-蛋白质生产。硫是三个含硫氨基酸（半胱氨酸，胱氨酸和蛋氨酸）的组成部分，它们是蛋白质的组成部分。这些氨基酸中存在约90％的植物S。-合成油。这就是为什么充足的硫对油料种子如此重要的原因。-酶的活化，有助于植物中的生化反应。-提高农作物产量并提高产品质量，这两者都决定了农民为其农产品获得的市场价格。-关于作物品质，S提高种子中蛋白质和油的百分比，碾磨和烘烤的谷物品质，干椰子仁（椰干）的适销性，烟草的品质，饲料的营养价值等。-它与植物中的特殊代谢和原生质体的结构特征有关。由于所有这些原因，监测并在必要时使用适当的肥料增加土壤中的硫含量非常重要。