Pheochromocytoma and paraganglioma (PPGL) are rare neuroendocrine tumors arising from adrenal and extra-adrenal chromaffin cells. They produce excessive amounts of catecholamines and their metabolites. A newly analytical procedure based on the semi-automated microextraction by packed sorbent (MEPS) technique, using a digitally controlled syringe (eVol) combined with liquid chromatography-tandem mass spectrometry (LC-MS/MS), was developed to quantify free urinary catecholamines and metanephrines. The important parameters affecting MEPS performance, namely the type of sorbent material (porous graphitized carbon (PGC), polar enhanced polymer (PEP), cation-exchange (CX) and C18), number of extraction cycles, and elution solvent system, were evaluated. The optimal experimental conditions involved the loading of sample mixture in seven extraction cycles through a C18 sorbent in a MEPS syringe, followed by using elution solutions (water/acetonitrile/formic acid, 95/4.75/0.25). The entire sample preparation took about 4 min. Chromatographic separation was well achieved with an HSS PFP column using the gradient elution. The linearity range of the method was 0.167-33.4 ng/mL for epinephrine, 0.650-130 ng/mL for norepinephrine, 1.53-306 ng/mL for dopamine, 1.34-268 ng/mL for metanephrine, 3.43-686 ng/mL for normetanephrine, and 1.33-265 ng/mL for 3-methoxytyramine. The intra- and interassay precisions were ≤ 12.8%, and the respective accuracies were 88.4-112.0% and 89.0-109.5%. The carryover and sample stability without acidification were also investigated. Validation using clinical urine specimens showed that the proposed method had higher sensitivity compared with other urinary biochemical tests. The developed MEPS-LC-MS/MS method was simple, fast, and cost-effective; it helped to obtain information about multiple metabolites. It is applicable in routine clinical laboratories for the screening of PPGL. Graphical abstract.

中文翻译：

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使用液相色谱-串联质谱法通过填充吸附剂方法进行简单，快速且经济高效的微量萃取，用于定量尿中游离儿茶酚胺和间肾上腺素，并将其应用于临床分析。

嗜铬细胞瘤和副神经节瘤（PPGL）是由肾上腺和肾上腺嗜铬细胞引起的罕见神经内分泌肿瘤。它们产生过量的儿茶酚胺及其代谢产物。开发了一种新的分析方法，该方法基于半自动微量吸附吸附技术（MEPS），结合数控注射器（eVol）和液相色谱-串联质谱（LC-MS / MS），用于定量尿中儿茶酚胺和间肾上腺素。评估了影响MEPS性能的重要参数，即吸附剂材料的类型（多孔石墨化碳（PGC），极性增强聚合物（PEP），阳离子交换（CX）和C18），萃取循环数和洗脱溶剂系统。最佳实验条件包括在七个萃取循环中通过MEPS注射器中的C18吸附剂加载样品混合物，然后使用洗脱溶液（水/乙腈/甲酸，95 / 4.75 / 0.25）。整个样品制备过程约需4分钟。使用HSS PFP色谱柱使用梯度洗脱可实现色谱分离。该方法的线性范围是肾上腺素0.167-33.4 ng / mL，去甲肾上腺素0.650-130 ng / mL，多巴胺1.53-306 ng / mL，间肾上腺素1.34-268 ng / mL，3.43-686 ng / mL去甲肾上腺素，3-甲氧基酪胺为1.33-265 ng / mL。批内和批间精密度≤12.8％，准确度分别为88.4-112.0％和89.0-109.5％。还研究了未酸化的残留和样品稳定性。使用临床尿液标本进行的验证表明，与其他尿液生化检查相比，该方法具有更高的灵敏度。所开发的MEPS-LC-MS / MS方法简便，快速且具有成本效益。它有助于获得有关多种代谢物的信息。它适用于常规临床实验室中PPGL的筛查。图形概要。