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

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.

Facile fabrication of naphthalene-functionalized magnetic nanoparticles for efficient extraction of polycyclic aromatic hydrocarbons from environmental water and fish samples

In this study, naphthalene-modified magnetic nanoparticles (Fe3O4@Nap) were simply prepared based on specific chelation interaction between phosphate groups and metal ions on Fe3O4 surface. The resultant Fe3O4@Nap were characterized by FTIR, BET, SEM, TEM, NAM, TGA, and VSM techniques. With Fe3O4@Nap as adsorbent, the polycyclic aromatic hydrocarbons (PAHs) were efficiently extracted by magnetic solid-phase extraction (MSPE) from environmental water and fish samples through the π-π interaction between modified naphthalene groups and PAHs, followed by their determination by GC-MS/MS. The key parameters influencing the extraction efficiency were investigated. Under the optimized conditions, the Fe3O4@Nap-based MSPE/GC-MS/MS method proposed in this paper was evaluated and applied for analyzing PAHs in environmental water and fish samples. And the proposed MSPE/GC-MS/MS method exhibited good linearities for water samples (in the range of 0.1-10 ng/mL, R2 >0.9945) and for fish samples (in the range of 1-100 ng/g, R2 > 0.9905). The limits of detection (LODs) for water and fish samples were 0.004-0.031 ng/mL and 0.07-0.28 ng/g, respectively. Additionally, this method exhibited desirable accuracy and precision. The PAH recovery values from water and fish samples ranged from 81.5% to 109.6% with inter- and intra-day relative standard deviations (RSDs) of less than 12.8%. The MSPE/GC-MS/MS method was successfully applied to the analysis of real environmental water and fish samples. Overall, the newly synthesized Fe3O4@Nap exhibited high sensitivity, specificity, reusability, repeatability, and it could efficiently extract PAHs from environmental water and fish samples by MSPE.

GC-MS/MS Method for Determination of Polycyclic Aromatic Hydrocarbons in Herbal Medicines

Polycyclic aromatic hydrocarbons (PAHs) are hydrophobic organic contaminants that have a highly carcinogenic and mutagenic nature. This study aimed to develop and validate a sensitive analytical method to determine 8 PAHs in 51 herbal medicines (HMs) using gas chromatography (GC)-tandem mass spectrometry (MS/MS). Liquid--liquid extraction and florisil SPE cartridge purification were basically adopted for pretreatment. For the samples containing essential oil, starch grain, etc., N,N-dimethyl formamide/water mixture (9:1, v/v) was added in the extraction step. The multiple reaction monitoring (MRM) conditions were newly obtained by the infusion of reference solutions of the targeted compounds at a concentration of 100 ng/mL into the GC-MS/MS system used in this study. The 51 items were classified according to whether or not they contained essential oil. Eight PAHs were not detected in 39 (8.3%) of the 459 samples monitored. The total content of 8 PAHs ranged from 0.45 μg/kg in Anemarrhenae Rhizoma to 270.94 μg/kg in Zingiberis Rhizoma. The average content of those ranged from 0.9 μg/kg in Araliae Continentalis Radix to 110.8 μg/kg in Coptidis Rhizoma Preparata cum Vinum. The results of this study prove that the proposed method is useful for determining 8 PAHs in HMs.

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.

Magnetic solid phase extraction and determination of polychlorinated biphenyls in beverages utilizing C60 modified magnetic polyamido-amine dendrimers in combination with gas chromatography-tandem mass spectrometry

Polychlorinated biphenyls (PCBs) are persistent organic pollutants which are widely present in environment and harmful to human health. In this study, an efficient and convenient magnetic solid phase extraction method with C₆₀ modified magnetic polyamido-amine (PAMAM) dendrimers as sorbents was established for enriching trace amounts of PCBs in beverage samples. Gas chromatography-tandem mass spectrometry (GC-MS/MS) was utilized for analysis of PCBs. Parameters affecting extraction efficiency were optimized. Under optimal parameters, good linearity can be achieved in concentration range of 0.001-20 μg L^-1 and 0.002-20 μg L^-1 for nine selected PCBs. The limits of detection for PCBs were in the range of 0.1-0.2 ng L^-1. The spiked recoveries were in the range of 87.0 %-115.1 % (n = 3). The results proved that this established method was reliable for monitoring trace PCBs in beverage samples.