Concentrations, Sources and Health Risk Assessment of Polycyclic Aromatic Hydrocarbons in Chinese Herbal Medicines

The determination and evaluation of 16 polycyclic aromatic hydrocarbons (PAHs) in seven Chinese herbal medicines (CHMs) were conducted through a rapid and straightforward extraction and purification method, coupled with GC-MS. A sample-based solid-phase extraction (SPE) pretreatment technique, incorporating isotopic internal standards, was employed for detecting various medicinal parts of CHMs. The assay exhibited linearity within the range of 5 to 500 ng/mL, with linear coefficients (R2) for PAHs exceeding 0.999. The recoveries of spiked standards ranged from 63.37% to 133.12%, with relative standard deviations (RSDs) ranging from 0.75% to 14.54%. The total PAH content varied from 176.906 to 1414.087 μg/kg. Among the 16 PAHs, phenanthrene (Phe) was consistently detected at the highest levels (47.045-168.640 μg/kg). Characteristic ratio analysis indicated that oil, coal, and biomass combustion were the primary sources of PAHs in CHMs. The health risk associated with CHMs was assessed using the lifetime carcinogenic risk approach, revealing potential health risks from the consumption of honeysuckle, while the health risks of consuming Lycium chinense berries were deemed negligible. For the other five CHMs (glycyrrhizae, Coix lacryma, ginseng, lotus seed, seed of Sterculia lychnophora), the health risk from consumption fell within acceptable ranges. Furthermore, sensitivity analyses utilizing Monte Carlo exposure assessment methods identified PAH levels in CHMs as health risk sensitizers. It is crucial to recognize that the consumption of herbal medicines is not a continuous process but entails potential health risks. Hence, the monitoring and risk assessment of PAH residues in CHMs demand careful attention.

Determination of polycyclic aromatic hydrocarbons in Chinese herbal medicines by gas chromatography-mass spectrometry with graphene-functionalized nickel foam

Graphene-functionalized nickel foam (NF) sorbent materials were prepared and characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy and Thermogravimetric analysis. For the separation and detection of polycyclic aromatic hydrocarbons (PAHs) in five Chinese medicine samples, namely dandelion, fructus aurantii, peppermint, mulberry leaf and embryo chrysanthemum, a method combining dispersive micro-solid phase extraction and gas chromatography-mass spectrometry (GC-MS) was developed. Four conditions affecting the extraction efficiency, such as the type of desorption solvent, the amount of sorbent, the extraction time and the volume of water sample, were optimized. The results of the methodological validation showed that NF@SiO₂@G was able to adsorb PAHs well and with good reproducibility. All analytes showed good linearity in the concentration range of 20-2000 ng/mL with coefficient of determination R²≥0.9956. The limit of detection was 0.98-13.34 ng/mL, and the limit of quantification ranged from 3.25 to 44.47 ng/mL. Both the intra-day and inter-day precision were lower than 15.46%, and the spiked recoveries were in the range of 75.5-118.4%. The total contents of the 16 PAHs contained in these five Chinese herbal medicines (CHMs) were varied from 450 to 1557 µg/kg. The results indicated that the graphene-functionalized NF sorbent combined with GC-MS can effectively detect PAHs in CHMs.

Dietary exposure and risk assessment of chlorinated paraffins in roots and rhizomes of traditional Chinese medicine herbs

Traditional Chinese medicine (TCM) provides therapeutic and health care effects through dietary intake. Owing to the susceptibility of plants to contaminations, a risk assessment system is urgently needed to ensure the safe use of TCMs. In this study, the contamination levels and risks associated with the dietary intake of short-chain chlorinated paraffins (SCCPs) and medium-chain chlorinated paraffins (MCCPs) were investigated in six kinds of frequently-used TCM herbs. The concentrations varied from 144.4 to 1527.8 ng·g-1 dw for SCCPs and non-detect to 1214.1 ng·g-1 dw for MCCPs, with mean values of 551.5 and 259.8 ng·g-1 dw, respectively. A geographic distribution analysis indicated that the concentrations of CPs in TCMs were mainly associated with their levels of contamination in the ambient environment. Carbon atom-chlorine congener profiles of CPs were dominated by C10Cl7-8 and C14Cl7-8 congeners, accounting for 20.1% and 32.4% of the total SCCP and MCCP concentrations, respectively. Principal component analysis indicated that the TCM species might be the main factor influencing the accumulation of SCCPs congeners. Finally, a risk assessment reveals that the estimated daily intake and margin of exposure were far below levels that might pose a health risk, indicating an acceptable dietary intake of SCCPs and MCCPs in the studied TCMs. This is the first report of CPs in the TCM herbs and the obtained results are expected to aid in future evaluation of the quality of TCMs and ensuring diet and drug safety.

Comparative Analysis of Polycyclic Aromatic Hydrocarbons and Halogenated Polycyclic Aromatic Hydrocarbons in Different Parts of Perilla frutescens (L.) Britt

Perilla frutescens (L.) Britt., a medicinal herb and edible plant, is very popular among East Asian countries. The perilla leaves, stems and seeds can be used as traditional medicines and foods. Polycyclic aromatic hydrocarbons (PAHs) and halogenated PAHs (HPAHs) are organic pollutants that are widely present in the environment, such as in water, air and soil, and are harmful to humans. In this study, the contents of 16 PAHs and 4 HPAHs in perilla leaves, stems and seeds were determined by gas chromatography tandem mass spectrometry (GC-MS). A total of 12 PAHs were detected in all samples, and no HPAHs were detected. The total contents of PAHs in perilla leaves, stems and seeds varied from 41.93 to 415.60 ng/g, 7.02 to 51.52 ng/g and 15.24 to 180.00 ng/g, respectively. The statistical analyses showed that there were significant differences in the distribution of PAHs in perilla leaves, stems and seeds. On the basis of the toxic equivalent quantity (TEQ) and incremental lifetime cancer risk (ILCR) model, the cancer risks of the intake of perilla leaves, stems and seeds were assessed to be from 3.30 × 10-8 to 2.11 × 10-5, 5.52 × 10-9 to 5.50 × 10-8 and 1.20 × 10-8 to 1.41 × 10-7, respectively. These were lower than 10-4 (the priority risk level of the EPA) and suggested that there may be almost no cancer risk from the intake of these traditional Chinese medicines (TCMs).

Magnetic C60 nanospheres based solid-phase extraction coupled with isotope dilution gas chromatography-mass spectrometry method for the determination of sixteen polycyclic aromatic hydrocarbons in Chinese herbal medicines

C₆₀-based magnetic nanospheres were synthesized by coating Fe₃O₄ nanospheres with silica, then modifying with 3-aminopropyltriethoxysilane as a linker and a C₆₀ fullerene stationary phase. The morphologies, magnetic properties, infrared absorption and carbon content of magnetic nanospheres were studied by TEM, VSM, FTIR and carbon and sulfur analyzer. The magnetic nanospheres were employed for the magnetic solid-phase extraction (MSPE) of 16 polycyclic aromatic hydrocarbons (PAHs) in nine Chinese herbal medicines. The analyses were conducted by isotope dilution gas chromatography-mass spectrometry. The main parameters influencing the extraction, including extraction solvent, adsorbent amount, and extraction time were optimized. Method validation showed that the limit of detection (LOD) was 0.02-0.11 µg/kg, and the limit of quantification (LOQ) was 0.07-0.36 µg/kg. The spiked recoveries rates for 16 PAHs in white peony root were 84.7-107.2%. The relative standard deviation (RSD) was 1.7-8.4%. The established method was further used for the determination 16 PAHs in nine Chinese herbal medicines. Total content of 16 PAHs varied from 73.6 µg/kg (fructus lycii) to 2172.6 µg/kg (astragalus root). The results indicate that the pollution of PAHs in Chinese herbal medicines is serious. The established method can effective detect PAHs contamination in Chinese herbal medicines.

The similarity and variability of the iridoid glycoside profile and antioxidant capacity of aerial and underground parts of Lamiophlomis rotata according to UPLC-TOF-MS and multivariate analyses

Lamiophlomis rotata (L. rotata) is a Tibetan medicinal herb used for centuries that contains iridoid glycosides (IGs), which are pharmacologically active ingredients and can be used for quality control. The IG profiles of the underground and aerial parts of the plant were determined by UPLC-TOF-MS to evaluate the similarity and variability of the different herbal parts listed in the Chinese Pharmacopoeia. Twenty-six IGs were detected in the total ion current (TIC) profile of L. rotata, and twenty-two of these were identified by comparing the retention times and mass spectra of the compounds to those of authentic standards. Among these compounds, five IGs with the same molecular formula (C17H26O11) were identified for the first time by mass spectrometry based on their different hydroxyl group-substituted positions. The aerial part has a similar chemical profile to that of the roots. The difference between the two parts was determined by multivariate statistical analysis of the UPLC-TOF-MS data of 24 specimens. Sesamoside was explored as the most characteristic marker to distinguish the two parts of L. rotata. To further estimate the distinction between the two parts, the content of total IGs and the antioxidant capacity were investigated in samples from different locations. The aerial parts showed a high content of total IGs and high antioxidant capacity, although not higher than those of the roots. The results also suggest the dosage should be increased when the aerial parts are used as crude medicinal materials instead of the underground parts.

Polycyclic aromatic hydrocarbons in the soil profiles (0–100 cm) from the industrial district of a large open-pit coal mine, China

Mining and industrial activities are the primary sources of soil pollution in the open-pit coal mine.