Benefits of Microwave Digestion over Open Acid Digestions
痕量金属分析Atomic Absorption Spectroscopy或ICP要求样品在引入系统之前处于液态状态。有时样品以液体形式出现，例如饮用水，饮料，酒，几乎不需要或不需要样品处理。但是，样品也可能是复杂的矩阵，例如身体组织，头发，血液，脂肪和油，矿物质，岩石，土壤，陶瓷，氧化物，氧化物等。在分析之前，使用酸消化提取这些样品，以清除金属。
The objective is to achieve complete decomposition of the solid matrix while preventing loss or contamination of the analytes.
湿化学消化利用各种矿物质酸，例如HNO3，HCL，HF，H2SO4，HCLO4或此类酸的组合。消化可以在大气压下在开放系统中或使用微波消化的温度升高。
在包含样品和大量酸的容器中进行常规的固体样品湿样品消化。使用热板或加热地幔将混合物长时间在烟雾罩中加热。当分析师感到消化完成时，加热就会停止。相反，微波消化可在受控条件下对无机和有机矩阵的消化。
Microwave digestion systems offer several distinct advantages over open digestions:
- 最大的好处是节约时间。同时heating of 8 – 12 samples is possible and reaction times are typically less than an hour in comparison to 5 – 12 hours or even more for open digestions.
- Time taken for a digestion is dependent on temperature.Open digestions are limited to boiling points of acids used whereas closed digestion systems can be operated at higher temperatures of 250 –300OC
由于能够承受更高的压力。 - Acid consumption is lower in microwave digestion
- Microwave digestion systems offer greater extraction efficiency whereas in open system digestion extraction can be incomplete depending on discretion of the analyst.
- 与开放消化相比，分析师没有暴露于腐蚀性酸烟雾中
- Loss of volatile elements such as Hg or Pb can take place in open digestion whereas in closed system digestions loss of volatile elements is prevented.
- A greater risk of contamination from external sources exists in open digestion whereas in closed systems the risk is non-existent
封闭的微波消化系统仅具有一个缺点，即由于同时积累而引起的消化管的爆炸和破裂 - 随着温度的升高，压力与压力升高。但是，微波系统具有用于温度和压力的内置传感器。当压力达到最大极限时，微波电源将自动控制或关闭。
Microwave closed system advantages far outweigh the disadvantage and is therefore a very useful addition to high throughput laboratories.
Please share your experiences of handling difficult digestions and leave your comments.
I am a fresh graduate of geology and am appointed as laboratory technologist , however, I am having a problem in rock digestion and extraction for AAS analysis , please help and support me on how are will become expert in doing that. thank you.
Hi Jungudo,
I would recommend joining of our certificate programme on AAS.Besides your sampling issues with rock samples you are sure to find solutions to your other doubts on the technique and its applications.The course will be launched very shortly. Please keep a lookout on its announcement on our site.
亲爱的Deepak博士现在，我打算前往英国参加AAS PG990石墨炉培训，请我需要您的建议。
Dear Jungudo,
Wishing you all the best for the visit to UK for your training.In case you have technical querries you are welcome to address me an I shall try to assist you to the best of my abilities.
dear Dr Deepak
with respect
我在化学实验室部门在乳制品公司工作，我有一个问题
请指导我，准备HPLC和GC的乳制品样品
我知道我们不需要GC和HPLC的微波酸消化，
我们的乳制品为GC准备样品的最佳方法是什么？和HPLC？
例如，我们在水溶性维生素中与产品分离有问题。
感谢您的关注
BR
jalali
Microwave digestions are not at all recommended for digestion of samples for chromatographic analysis. Microwave digestion rapidly raises the sample temperature and samples for chromatographic analysis will most likely degrade at such temperatures . The most common sample dissolution technique is to immerse the sample tube or flask in a water filled ultrasonic bath and sonicate for the recommended time to allow complete dissolution.
先生，你好，
来自Nirav Patel印度的问候。
我希望知道适当的方法进行高纯度石英分析作为其消化方法和分析仪器的选择和调整。
Thank you