Oil immersed transformer is one of the main equipment in the power grid system, which contains a large amount of insulation oil and insulation paper. Over time, insulation oil and paper will gradually age, and the insulation effect will deteriorate, affecting the effectiveness and safety of transformer use. Insulation oil can be regenerated or replaced during the use of transformers, but the aging of insulation paper cannot be restored. The aging degree of insulation paper is an important indicator to determine whether the transformer needs to be replaced.

Referring to the national standard (GB/T 23495-2009), a new high-performance LC500HPLC high-performance liquid chromatograph was used to provide HPLC detection schemes for benzoic acid, sorbic acid, acesulfame, and sodium saccharin through practical testing. The results obtained are accurate and reliable, with good detection limits, suitable for the determination of benzoic acid, sorbic acid, acesulfame, and sodium saccharin in red wine, and are only for reference by users. The following are detailed detection methods for benzoic acid, sorbic acid, acesulfame, and sodium saccharin.

This scheme is used to detect the content of hyperoside in the traditional Chinese medicine herb Cuscuta chinensis. According to the 2020 edition of the Chinese Pharmacopoeia, a C18 chromatographic column and UV detector are required.

This scheme is used to detect the steroidal components of amaranth in the traditional Chinese medicine herb Sichuan Achyranthes. According to the 2020 edition of the Chinese Pharmacopoeia, a C18 chromatographic column and UV detector are required.

This scheme is used to detect the content of coumarin glycoside and 5-O-methylvisamminol glycoside in traditional Chinese medicine Fangfeng. According to the 2020 edition of the Chinese Pharmacopoeia, a C18 chromatographic column and UV detector are required.

This scheme is used to detect gastrodin and p-hydroxyphenylmethanol in traditional Chinese medicine Tianma. According to the 2020 edition of the Chinese Pharmacopoeia, a C18 chromatographic column and UV detector are required.

This scheme is used to detect harpagoside and harpagoside in the traditional Chinese medicine herb Xuanshen. According to the 2020 edition of the Chinese Pharmacopoeia, a C18 chromatographic column and UV detector are required.

This scheme is used to detect Qianghuol and isoquercetin in the traditional Chinese medicine herb Qianghuo. According to the 2020 edition of the Chinese Pharmacopoeia, a C18 chromatographic column and UV detector are required.

This scheme is used to detect mannose in the traditional Chinese medicine herb Dendrobium officinale. According to the 2020 edition of the Chinese Pharmacopoeia, a C18 chromatographic column and UV detector are required.

This scheme is used to detect geniposide in Chinese herbal medicine stir fried gardenia. According to the 2020 edition of the Chinese Pharmacopoeia, a C18 chromatographic column and UV detector are required.