Research on the rapid detection of illegally added health chemicals in health products using TLC-NIRS combined technology
With the increasing awareness of public health care, people’s demand for health products is growing day by day, especially those labeled with traditional Chinese medicine. Health supplements are a common term for health food, which are called dietary supplements in foreign countries. They do not belong to the category of drugs and have the ability to regulate human functions. They are used for specific populations to consume, but not for the purpose of treating diseases. Faced with the temptation of high profits, illegal vendors have added chemical raw materials with low prices and obvious side effects to health products in excessive doses to enhance product efficacy, which has greatly disrupted the health product market in China and posed a serious threat to national health. For example, in 2009, the illegal drug glibenclamide was added in excessive doses to the auxiliary hypoglycemic health product “Tangzhining Capsules” in Xinjiang, causing multiple deaths; in 2014, the illegal drug sibutramine and sildenafil were added to the “Xianxian Weight Loss Capsules” in Shanxi Province, causing multiple adverse reactions and even deaths; in recent years, it has been found in health product inspections and evaluations that illegal manufacturers have added excessive amounts of sildenafil to sexual health products and traditional Chinese medicine health products to deceive consumers, seriously endangering consumer health; The phenomenon of excessive addition of banned chemicals such as nalphine, biguanide, furosemide, and phenolphthalein in sexual health, blood sugar lowering, and weight loss products is constantly emerging, and the concealment of the addition is becoming increasingly high; This phenomenon also frequently occurs abroad. These illegal behaviors with wide impact and great harm are worthy of deep consideration by the drug regulatory authorities, and it is particularly important to develop rapid market sampling and testing methods.
At present, the detection methods for illegally added chemicals in traditional Chinese patent medicines and simple preparations and health products mainly include thin layer chromatography (TLC), high performance liquid chromatography (HPLC), liquid chromatography mass spectrometry (LC-MS), gas chromatography mass spectrometry (GC-MS), ion mobility spectrum (IMS) and Raman Spectrum (RS), etc. Among the various reported detection methods, LC-MS, GC-MS, and IMS have been studied relatively extensively. However, due to their high instrument prices, complex operations, and difficulty in promotion, they are difficult to popularize in economically underdeveloped urban and mountainous areas. TLC is one of the four major identification methods for traditional drugs, characterized by its speed, simplicity, and good separation effect. It is widely used in the qualitative and quantitative identification of drugs, but its disadvantage is that it requires corresponding reference standards or reference medicinal materials. Near infrared spectroscopy (NIRS) has been developed in recent years to collect vibrational and rotational absorption information of the detected substance in the near-infrared spectral region, including C-H, O-H, S-H, N-H, C=C, and C=O groups, for qualitative and quantitative analysis of substances. It is widely used in agriculture, petroleum, chemical, tobacco, and food industries, and has gradually been applied in the pharmaceutical and drug regulatory industries, with great potential for rapid qualitative and quantitative detection and analysis of drugs. Therefore, this article intends to use existing widely used instruments and testing methods to create TLC-NIRS combined technology. Taking sexual health products as an example, a universal qualitative and quantitative detection model for illegal addition of prohibited sexual health chemical drugs is established, which can be efficiently, quickly, and conveniently used for screening and detecting the addition of prohibited chemical drugs in market health products, reducing detection costs.

This study first created the TLC-NIRS combination technique because TLC is a classic traditional identification analysis method with advantages such as easy operation and strong universality. TLC has a large free space for sample processing, and different extraction solvents can be selected for possible addition of prohibited chemicals, which effectively avoids the influence of different manufacturers’ products on NIRS due to different excipients; There are many materials available for TLC, such as silica gel, alumina, polyamide, etc. The developing agent can choose different polarity reagents to be suitable for the separation and analysis of different types of chemical components. At the same time, different unfolding systems can be used for bidirectional unfolding, which has a good separation effect and can greatly improve the accuracy of NIRS in collecting chemical drug information. NIRS is a rapidly developing analytical instrument in recent years, characterized by easy operation, fast analysis speed, and no chemical pollution. This article combines their respective advantages to create the TLC-NIRS combination technology for the first time, and conducts a systematic methodological examination of this method. A rapid qualitative and quantitative analysis model for the addition of prohibited chemicals sildenafil and naldenafil in health products has been established. The model has been validated and evaluated using a validation set of samples, and the qualitative model can effectively determine whether the above-mentioned prohibited chemicals are added to health products, with a 100% accuracy rate; The quantitative model can accurately predict the content of added sildenafil and naldenafil, with a wide prediction range of 5.25-262.5 and 5.15-257.5 μ g/μ L, respectively. The average relative deviations in the prediction results of 10 health products are 1.86% and 1.96%, respectively. The prediction results have achieved good results and can meet the needs of practical rapid testing. In practical work, TLC-NIRS combined technology was applied to crack down on multiple batches of sexual health products containing excessive doses of the banned chemical sildenafil.
This study selected non fungible drugs as the research object, because non fungible drugs have definite effects, low prices, and are easy to obtain in sexual health products, making them the preferred additives for illegal manufacturers. In addition, this type of sexual health medication should achieve the expected effect, with an effective dose of 50-100mg per dose. Long term overdose can cause serious liver and kidney damage and permanent loss risks. The use of TLC-NIRS model to predict the addition of non fungible drugs in sexual health products has certain feasibility and research value.
This article utilizes the existing analytical techniques and instruments on the experimental platform for combination and application, which has shown good results in practical drug testing. The TLC-NUIRS combined technology developed has great application prospects in addressing issues such as uneven quality, diverse production varieties, difficulty in unifying auxiliary material sources, and serious illegal additives in healthcare product manufacturing enterprises. The theoretical and practical research on the application of this combined technology provides a scientific basis for the development of TLC-NIRS combined instruments and equipment.