Benzoic, sorbic and propionic acid are used as preservatives in foods and can also be naturally present in processed foods. The levels of preservatives in 939 vegetables were determined. Benzoic and sorbic acid were analysed by high-performance liquid chromatography with a diode-array detector and further confirmed by liquid chromatography-tandem mass spectrometry, whereas propionic acid was analysed using a gas chromatography-flame ionization detector and further confirmed by gas chromatography-mass spectrometry. Benzoic and propionic acid were found in 10.9% and 36.2%, respectively, of the samples. In contrast, sorbic acid was not found in any of the samples. The highest amounts of benzoic and propionic acid were found in perilla leaves (0.33−298 mg kg^–1) and ginseng (<LOD−32.8 mg kg^–1), respectively. The background concentration ranges of naturally occurring preservatives in vegetables determined in this study could be used for inspection services of standard criteria to address consumer complaints or trade disputes.

苯甲酸，山梨酸和丙酸在食品中用作防腐剂，也可以天然存在于加工食品中。确定了939种蔬菜中的防腐剂含量。苯甲酸和山梨酸通过高效液相色谱仪和二极管阵列检测器进行分析，并进一步通过液相色谱-串联质谱法进行确认，而丙酸使用气相色谱-火焰电离检测器进行分析，并进一步通过气相色谱-质谱法进行确认光谱法。样品中苯甲酸和丙酸的含量分别为10.9％和36.2％。相反，在任何样品中均未发现山梨酸。紫苏叶（0.33−298 mg kg ^–1）和人参（<LOD−32.8 mg kg ^–1）中发现的苯甲酸和丙酸含量最高）， 分别。本研究确定的蔬菜中天然防腐剂的背景浓度范围可用于标准服务的检验服务，以解决消费者的投诉或贸易纠纷。