Capillary liquid chromatography with MS3 for the determination of enkephalins in microdialysis samples from the striatum of anesthetized and freely-moving rats
Capillary liquid chromatography with MS3 for the determination of enkephalins in microdialysis samples from the striatum of anesthetized and freely-moving rats
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DOI：
10.1002/jms.733
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发表时间：
2005-02-01
影响因子：
2.3
通讯作者：
Kennedy, RT
中科院分区：
文献类型：
--
作者：
Baseski, HM;Watson, CJ;Kennedy, RT
采用体内微透析取样与毛细管液相色谱(LC)/电喷雾电离四极离子阱质谱（MS）联用，监测麻醉和自由活动大鼠纹状体中的[Metlenkephalin]和[Leu]脑啡肽。LC系统利用高压泵在12分钟内上样2.5 ml，用2 cm长的色谱柱对25 ml的样品进行脱盐。样品用单独的泵以类似于100 nl min（-1）的速度洗脱。快速梯度在4分钟内有效分离内源性神经肽。比较了质谱仪在MS2和MS3模式下的检测效果。在标准溶液中，1- 2pm（注射2-4 amol）的检出限相似；然而，MS'的重复性提高了，相对标准偏差< 5%，而MS2对60 pM样品的相对标准偏差为20%。对于透析液溶液，重构离子色谱和串联质谱在MS3模式下具有更高的信噪比，从而在体内浓度下进行更可靠的检测。该方法成功地用于基础条件下和通过输注升高K+浓度刺激肽分泌的肽监测。版权所有(C) 2005约翰威利股份有限公司
In vivo microdialysis sampling was coupled to capillary liquid chromatography (LC)/electrospray ionization quadrupole ion trap mass spectrometry (MS) to monitor [Metlenkephalin and [Leu]enkephalin in the striatum of anesthetized and freely-moving rats. The LC system utilized a high-pressure pump to load 2.5 mul samples and desalt the 25 mum i.d. by 2 cm long column in 12 min. Samples were eluted with a separate pump at similar to100 nl min(-1). A rapid gradient effectively separated the endogenous neuropeptides in 4 min. A comparison was made for operating the mass spectrometer in the MS2 and MS3 modes for detection of the peptides. In standard solutions, the detection limits were similar at 1-2 pM (2-4 amol injected); however, the reproducibility was improved with MS' as the relative standard deviation was < 5% compared with 20% for MS2 for 60 pM samples. For dialysate solutions, reconstructed ion chromatograms and tandem mass spectra had much higher signal-to-noise ratios in the MS3 mode, resulting in more confident detection at in vivo concentrations. The method was successfully used to monitor the peptides under basal conditions and with stimulation of peptide secretion by infusion of elevated K+ concentration. Copyright (C) 2005 John Wiley Sons, Ltd.