一种评估醋质量的新方法：小型传感器（S3）装置与浸提耦合应用

Abstract
In this work is illustrated the application of S3 (Small Sensor System) device, equipped with an array of six metal oxide semiconductor (MOX) gas sensors, coupled with enfleurage as new approach to characterize the aromatic profile of Balsamic Vinegars (BVs). Thanks to the enfleurage in fact, the lipophilic volatile compounds are extracted from balsamic vinegar while acetic acid and its derivatives whose high concentration negatively influences MOX sensors sensitivity are not involved in the process. The obtained results show the huge potentiality of this new approach to evaluate BVs quality. All the samples were analyzed in parallel by GC-MS (Gas Chromatography-Mass Spectrometry) with SPME (Solid Phase Micro-Extraction).

本文介绍了S3（Small Sensor System，小传感器系统）装置的应用，该装置配备了六个金属氧化物半导体（MOX）气体传感器阵列，并结合浸提作为一种新的方法来表征香醋的芳香族分布。事实上，由于这一过程，从香醋中提取了亲脂性挥发性化合物，而乙酸及其衍生物的高浓度对MOX传感器灵敏度没有影响。研究结果表明，该方法在BVs质量评价中具有巨大的潜力。所有样品均采用气相色谱-质谱（GC-MS）和固相微萃取（SPME）并行分析。

Keywords: MOX gas sensors; GC-MS with SPME; Balsamic Vinegars; Enfleurage.

关键词：MOX气体传感器；气相色谱-质谱-固相微萃取；香醋；浸提

2.3. GC-MS with SPME
GC-MS analysis was performed using a Shimadzu Gas Chromatograph GC2010 PLUS (Kyoto, KYT, Japan) equipped with a Shimadzu single quadrupole Mass Spectrometer MSQP2010 (Kyoto, KYT, Japan) ultra and a HT280T auto-sampler (HTA S.r.l., Brescia, Italy) that permitted SPME analysis. The vials were incubated in an oven thermostatically regulated at 40ºC for 15 minutes due to create the headspace equilibrium. In order to extract the volatile compounds of the samples was used a DVB/CAR/PDMS (50/30um) (Supelco Co., Bellefonte, PA, USA) SPME fiber. To provide the adsorption of volatile compounds, the SPME fiber was exposed to the headspace of the vials for 15 minutes at 40°C. For desorption of the compounds, the fiber was placed in the injector of the heated GC for 6 min at 220°C. Volatile compounds were separated using an analytical capillary column (DB-WAX capillary column, 30m x 0.25 mm x 0.25um, Agilent Technologies, Santa Clara, CA, USA) and the carrier gas was ultrapure helium (99.99%) at a constant flow rate of 1.5 ml/min. The temperature program for the GC was performed in the following way: 40 °C for 3 min, increased to 220 °C at a rate of 4.5°C/min, with a 1 min of holding time. For each SPME analysis, 1 g of fat, saturated or clean, was placed in a 20 ml chromatographic vial. The determination of aromatic profile of BVs was carried out placing 2 ml of sample in a 20 ml chromatographic vial.

GC-MS分析使用岛津气相色谱仪GC2010 PLUS（Kyoto, KYT, Japan），配备岛津单四极杆质谱仪MSQP2010（Kyoto, KYT, Japan）ultra和HT280T自动取样器（HTA S.r.l., Brescia, Italy）进行SPME分析。将小瓶在40℃恒温调节的烘箱中培养15分钟，以达到顶空平衡。为了提取样品中的挥发性化合物，使用了DVB/CAR/PDMS（50/30um）（Supelco Co., Bellefonte, PA, USA）SPME纤维。为了提供挥发性化合物的吸附，SPME纤维在40°C下暴露于小瓶的顶部空间15分钟。为了解吸化合物，将纤维置于220°C下加热的GC注射器中6分钟。使用分析毛细管柱（DB-WAX毛细管柱，30m x 0.25 mm）分离挥发性化合物x 0.25um，Agilent Technologies，Santa Clara，CA，USA），载气为超纯氦（99.99%），恒定流速为1.5 ml/min。GC的温度程序按以下方式执行：40°C持续3分钟，以4.5°C/min的速率增加至220°C，保持时间为1分钟。对于每个SPME分析，将1g饱和或干净的脂肪放入20ml色谱小瓶中。在20ml色谱小瓶中放置2ml样品，测定BVs的芳香族分布。