[High-throughput screening of 54 alternative plasticizers in sesame oil using gas chromatography-quadrupole time-of-flight mass spectrometry].

Restrictions on the use of phthalates have led to the wide use of alternative plasticizers (APs) such as organophosphate, adipate, citrate, and sebacate. However, because plasticizers combine with polymers in plastic products via unstable noncovalent bonds, they can easily migrate out of these products, causing environmental pollution. In particular, their migration out of food packaging, containers, and other food-contact materials and into food has raised great concerns. Toxicological studies have shown that APs contain potentially toxic substances that can affect endocrine functions and cause neurotoxicity, genotoxicity, and other adverse effects. Thus, their potential risks to food should not be underestimated. Sesame oil is a necessity in daily cooking. The results of risk monitoring in recent years have indicated that sesame oil often contains phthalates in excess of the standard limits. However, the potential risks of APs in sesame oil have not yet been reported. Some common detection methods for APs include gas chromatography-mass spectrometry, gas chromatography-triple quadrupole mass spectrometry, and liquid chromatography-triple quadrupole mass spectrometry. Unfortunately, these methods use low-resolution mass spectrometry and are limited by the resolution, scan rate, and analysis mode. Gas chromatography-quadrupole time-of-flight mass spectrometry (GC-Q-TOF/MS) has the advantages of high resolution, sensitivity, and analysis speed. In full-scan mode, GC-Q-TOF/MS can accurately collect the full-spectrum mass number of target compounds with low content levels in complex substrates, thereby realizing efficient screening and quantitative analysis. It shows outstanding advantages in the trace analysis of pesticide residues and pollutants. Furthermore, it features strong qualitative and high screening abilities. Establishment of a personal compound database and library (PCDL) addresses limitations in the number of compounds that can be measured and enables the rapid identification of targets without the use of standard products. In addition, increasing the number of targets for synchronous screening enables the retrospective analysis of new targets. In this study, a method based on GC-Q-TOF/MS was developed for the determination of 54 APs in sesame oil. The samples were extracted with acetonitrile and purified using a PSA/silica solid-phase extraction column. The mass-spectral information of the samples was then collected by GC-Q-TOF/MS in full-scan mode, and the 54 APs were searched using an established high-resolution mass-spectrum database to simultaneously achieve the broad-spectrum screening, qualitative identification, and quantitative analysis of multiple targets. The effects of different extraction solvents and purification methods on sample extraction and purification were compared. The accuracy of the screening results was improved by optimizing the GC-separation conditions, quality-extraction window, retention-time deviation, and other screening parameters. The screening detection limits (SDLs) of the 54 APs ranged from 0.01 to 0.02 mg/kg; specifically, the SDL of 41 compounds was 0.01 mg/kg and that of 13 compounds were 0.02 mg/kg. The limits of quantification were in the range of 0.02-0.04 mg/kg. A total of 80 sesame-oil samples were rapidly screened using this method under optimal conditions. Five APs were identified from the 80 sesame-oil samples and quantitatively analyzed using the matrix-matched external-standard method. The results of this quantitative methodology showed that the five APs had good linear relationships in the range of 0.01-0.2 mg/L, with all correlation coefficients greater than 0.99. The accuracy and precision of the method were verified using a standard recovery test with blank sesame-oil samples. Under the three standard levels of 0.04, 0.08, and 0.2 mg/kg, the recoveries of the five APs ranged from 71.3% to 97.8%, and the relative standard deviations (RSDs) ranged from 0.4% to 6.1%(n=6). The developed method is fast, accurate, sensitive, and has high throughput. Thus, it can realize the efficient screening, qualitative identification, and quantitative analysis of the 54 APs in sesame oil and provides a potential solution for the monitoring of other contaminants in food.

[Diversity, antibacterial activites and growth promoting characteristics of endophytic fungi from sandal (Santalum album)].

The aim of this study was to investigated the biological diversity, antibacterial activites and the plant growth-promoting traits of endophytic fungi of sandal (Santalum album), and to assess their potential in the development of antibacterial substances and rapid cultivation of sandal. The results of isolation and taxa analysis of endophytic fungi from sandal showed that 325 strains of endophytic fungi belonging to 16 genera of endophytic fungi were isolated from sandal (of which 86 from roots, 105 from stems and 134 from leaves). The isolation rate and colonization rate of endophytic fungi in different sandal parts showed the same pattern of change: leave>stems>roots. The diversity index of endophytic fungi in sandal roots was significantly higher than that of stems and leaves. The dominant endophytic fungi of sandal roots, stems and leaves showed significant differences. The dominant endophytic fungi of roots were Fusarium (50.00%) and Alternaria (10.47%), Alternaria (58.11%) and Acremonium (20.00%) for stems, and Pantoea (74.63%) for leaves. The antibacterial activity of 40 representative strains of sandal endophytic fungi were analyzed and the results showed that 90% of endophytic fungi exhibited inhibitory activity against at least one of the tested bacteria strains, and the strains with inhibitory activity to Escherichia coli, Enterobacter aerogenes, Shigella dysenteriae, Salmonella typhimurium, Staphylococcus aureus, and Bacillus subtilis accounted for 45.0%, 30%, 47.5%, 55%, 72.5%, and 62.5%, respectively. The sandal fungal endophytes with plant growth-promoting characteristics were screened, and 5 strains of endophytic fungi with phosphorus-solubilizing activity, 8 strains of endophytic fungi producing IAA, and 4 strains of endophytic fungi producing siderophores were found. Among them, endophytic fungus Monilia sp TXRF45 clould produced IAA and siderophores, and also show phosphate-solubilizing activity. The results indicated that the endophytic fungi of Sandal were rich in species diversity and their distribution had a certain tissue specificity. Some strains showed good antibacterial activity and growth-promoting properties, which could potentially applicable for the development of antibacterial substances and rapid cultivation of sandal.

[Determination of 15 trace elements in antineoplastic traditional Chinese medicine by atomic absorption spectrometry].

Five kinds of antineoplastic traditional Chinese medicines including fufangtianxian capsule, xiaoaiping tablet, zhiling capsule, shenlian capsule and shenlinglan capsule were digested with HNO3-HCl mixed acid. The fifteen trace elements including calcium, magnesium, potassium, sodium, iron, zinc, manganese, cobalt, nickel, chromium, silver, copper, strontium, cadmium and lead in the above-mentioned drugs were determined by atomic adsorption spectrometry. The effects of the kinds of mixed acid, the ratio of HNO3 to HCl in the mixed acid, the volume of digesting solution and the digesting time were also investigated in detail. The results obtained show that the concentrations of Ca, Mg, K, Na, Fe, Zn, Mn, Co and Ni in the five kinds of antineoplastic Chinese traditional medicines are higher than those of other elements.

[Determination of trace elements in sika bone powder by inductively coupled plasma mass spectrometry with microwave digestion].

Contents of trace elements in sika bone powder were determined with microwave digestion and inductively coupled plasma mass spectrometry. Under the optimum conditions, the detection limits (3sigma, n = 11) are in the range of 0. 000 6-1. 498 ng x mL(-1) with relative standard deviations of 1.7%-6.8%. The recoveries are between 91% and 109%. The analytical results of national certified reference demonstrated the applicability of the proposed method.

[Determination of eleven trace elements in Chinese traditional and herbal drugs for relieving heat and toxic by FAAS].

Chinese traditional herbal drugs for relieving away heat and toxic were treated with cineration, and the residues were dissolved by HNO3. Eleven trace elements including, calcium, magnesium, manganese, copper, iron, zinc, cadmium, lead, cobalt, nickel and chromium in twenty sample solutions were determined by flame atomic absorption spectrometry. The results obtained show that the contents of calcium, magnesium, iron, zinc, manganese and copper are abundant, and the addition standard recoveries (n=5) were 90%-110%.

[Determination of fourteen trace elements in chinese traditional medicines by atomic absorption spectrometry].

Seven kinds of Chinese traditional medicines, including laoniankechuan tablet, fufangbanxia tablet, weitongning tablet, quanshen tablet, shengshijiangtang capsule, xiasangju particle, and American yangshen tablet, were digested with HNO3-HClO4 mixed acid. The fourteen trace elements, including calcium, magnesium, iron, zinc, potassium, sodium, manganese, copper, chromium, cobalt, strontium, nickel, cadmium and lead in the drugs were determined by atomic absorption spectrometry. The effects of the type of mixed acid, the ratio of HNO3 to HClO4 in mixed acid, the volume of digesting solution, and the digesting time were also investigated in detail. The results obtained show that the concentrations of Ca, Mg, Fe, K and Na in seven kinds of Chinese traditional medicines are higher than those of other elements. Moreover, shengshijiangtang capsule for the treatment of diabetes contains plenty of Mn, and weitongning tablet for the treatment of stomach disease contains plenty of Sr, Mn and Cu.