Utilizing angiotensinIThe extraction is relatively traditionalSPEPerformance of columns and magnetic extractants

keywords

angiotensinILiquid chromatography-mass spectrometry, solid-phase extraction,Angiotensin I，Ang I，Renin，LC-MS/MS，SPE

Preface

angiotensinI（Ang I）It is one of the more common clinical biomarkers, which is detected by detecting angiotensinIThe testing of extraction efficiency can effectively evaluate the clinical applicability and technical performance of various sample pretreatment methods.

This article compares a well-known imported brand on the marketHLB 96bitSPEPorous plate andHLBmagnetismSPEExtraction agent extractionAng IVarious methodological indicators of the experiment were used to visually compare the performance of the two. Also for clinical useSPEThe development prospects of sample pretreatment technology provide very valuable references.

Experimental Design

As shown in the table below, use1% BSAPrepare four concentration levelsAng ISeries standard solution, supplemented with stable isotope labelingAng IInternal standards.

Set the following conditionsSPEApplied to a well-known imported brandHLB 96bitSPEPorous plate. Use compatible positive pressure96KongSPEOperate the device to run the sample.

Correspondingly, forAUTO M32The fully automatic extractor is set to run samples using the following program, with each sample using2mg HLBMagnetic extractant.

Data and Comparison

Extract the four standard samples described in the experimental design three times for each sample, compare the two pre-treatment methods for extraction, and thenLC-MS/MSThe relative standard deviation measured above is shown in the following figure. Among them, the blue column on the left represents the use of a famous imported brandHLB 96bitSPEThe measurement results after extraction with a porous plate, and the orange column on the right shows the measurement results after extraction with a magnetic extractant.

It can be seen that there is no significant difference in the relative standard deviation of the two preprocessing methods in terms of external peak area, internal standard peak area, and calculated concentration. However, the results of magnetic extractants are slightly better than traditional ones at most levels96bitSPEPorous plate.

In the comparison of extraction rates, we chose a well-known imported brandHLB 96bitSPEThe peak area measured after extraction from the porous plate is used as the reference（100%）Compare the peak area measured after extraction with magnetic extractant. As shown in the figure below, the blue column on the left represents the use of a well-known imported brandHLB 96bitSPEThe measurement results after extraction with a porous plate, and the orange column on the right shows the measurement results after extraction with a magnetic extractant.

Finally, the MRM chromatograms obtained by LC-MS/MS after two methods of LOQ level extraction are shown in the following figure. Figure A shows the chromatogram obtained using a traditional 96 bit SPE porous plate, while Figure B shows the chromatogram obtained using a magnetic extractant. It can be seen that at all concentration levels, the peak area measured by magnetic extractant extraction is significantly better than that of traditional extraction96bitSPEPorous plates, all exceeding the latter50%Above, the highest even reached about1.8Twice.

Results and discussion
Clearly, inLOQAt the horizontal level, the chromatographic peak height obtained by magnetic extractant extraction exceeds that of traditional extraction96bitSPEThe extraction of porous plates is consistent with the extraction rate results.

By comparing the above data, we can obtain the results as shown in the table below.

All are superior to a well-known imported brandHLB 96bitSPEPorous plate. Meanwhile,AUTO M32The inherent "one-time pipetting" and "unmanned" operation modes of the fully automatic extractor reduce human involvement in sample pretreatment and significantly improve the level of automation.