Solid-phase extraction instrument is to use solid adsorbent to adsorb the target compound in liquid sample , separate it from the matrix and interference compound of the sample , and then elute or desorb it with eluent to achieve the purpose of separating and enriching the target compound ( The separation, purification and enrichment of the sample is aimed at reducing sample matrix interference and improving detection sensitivity. It is used in various food safety testing, agricultural product residue monitoring, medical and health, environmental protection, commodity inspection, tap water and chemical production laboratories. .
Here are some common questions about SPE
First, what kind of sampling method is best for solid phase extraction?
At present, positive pressure loading and negative pressure loading are commonly used in the market for extraction. However, due to the inability to effectively control the flow rate due to negative pressure loading, the recovery rate is unstable and the instrument repeatability is poor. Therefore, mainstream manufacturers generally use positive pressure. In this way, Haiergy fully automatic solid phase extraction instrument uses a high-precision injection pump to elute samples with positive pressure to more precisely control the flow rate of the liquid, thereby significantly improving instrument repeatability and ensuring sample recovery.
Second, automatic solid phase extraction sample processing speed what are the requirements?
The solid-phase extraction cycle of a single sample is generally about 20 minutes, and the general manufacturer's solid phase extraction apparatus is similar. Therefore, in general, the greater the number of samples that the instrument is synchronizing, the faster the processing speed. Haiergy fully automatic solid phase extraction adopts 6 channels + 3 modes of flexible extraction, which maximizes the sample processing speed.
Third, the automatic solid phase extraction instrument can effectively avoid the flow path during the extraction of the plug?
Problems often encountered in the application of automatic solid phase extraction instrument: instrument failure caused by blocked flow channels.
When column plugging occurs, most solid phase extractors cannot automatically detect and leak samples and solvents, causing serious losses and cross-contamination. Haiergy fully automatic solid phase extraction instrument flow path built-in high sensitive pressure sensor, when the flow channel pressure > 0.6Mpa , the system will automatically alarm, so as to effectively protect the device.
Fourth, automatic solid-phase extraction instrument can effectively control the cross-contamination?
Some automatic solid-phase extraction instruments, the same pipeline used for the sample and the solvent, are likely to cause pollution, especially the instruments without the cleaning function. In a short time, the pipeline will leave many compounds, which is the root cause of many experimental failures. . Haiergy fully automatic solid phase extraction instrument adopts the flow path separation unit to automatically select the solvent, and the organic solvent waste liquid has an independent waste liquid passage, which effectively avoids cross contamination.
Fifth, how should the user choose the appropriate solid phase extraction method?
To establish a solid phase extraction method, the easiest way is to find out from the published standard literature or information provided by SPE column manufacturer. However, because the sample matrices may be different, even if the target compounds are different, the methods provided by the literature are not necessarily the most optimized methods. Therefore, the extraction parameters in these methods need to be optimized.
Establishing a solid phase extraction method is divided into three steps:
( a ) Bring together relevant information;
( b ) Establish a preliminary solid phase extraction method;
( c ) Optimize the parameters in the method;
Automatic SPE sea can AutoSPE meter control software is a user-friendly, icon of the operating software in Chinese, from the establishment of the system configuration, a method of establishing a special instruction to fully consider the needs of users. The software's internal solid-phase extraction instructions include activation, sample loading, elution, drying, elution, and commonly used liquid handling instructions in the laboratory, making the method easier to set up and optimize.
Six, common problems in solid phase extraction:
( 1 ) Flow rate problems: Vacuum, pressure, gravity, and other factors can affect the flow rate of liquid through the SPE column. The stable flow rate is very important for the extraction efficiency, especially the sample column and elution steps. Excessive flow rate will reduce the recovery of the target compound, especially solid phase extraction based on ion exchange. Slow flow rate will prolong analysis time and reduce work efficiency.
Hanon AUTOSPE uses six high-precision ceramic metering pumps, which apply positive pressure to ensure accurate delivery of the fluid at a specified flow rate, ensuring high accuracy and repeatability of the analysis results.
( 2 ) Recovery rate problem: Generally speaking, when the result of extraction recovery rate is not satisfactory, it should be carefully and systematically eliminated one by one to find the cause, and then the extraction method should be improved. Establish a stable and reliable SPE method. In SPE , the flow rate can directly affect the final result, so controlling the flow rate is critical.
( 3 ) Pollution problems: The pollution produced by the SPE column depends to a large extent on the concentration of the target compound and the detection method used. Manufacturers with quality control can usually control pollutants on the order of PPb , and pollutants below this order may exist. If these contaminants interfere with the detection of the target compound, the SPE column should be pre-cleaned.
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