Green Analysis: High Throughput Analysis of Emerging Pollutants in Plant Sap by Freeze-Thaw-Centrifugal Membrane Filtration Sample Preparation-HPLC-MS/MS Analysis.

Emerging and fugitive contaminants (EFCs) released to our biosphere have caused a legacy and continuing threat to human and ecological health, contaminating air, water, and soil. Polluted media are closely linked to food security through plants, especially agricultural crops. However, measuring EFCs in plant tissues remains difficult, and high-throughput screening is a greater challenge. A novel rapid freeze-thaw/centrifugation extraction followed by high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) analysis was developed for high-throughput quantification of 11 EFCs with diverse chemical properties, including estriol, codeine, oxazepam, 2,4-dinitrotoluene, 1,3,5-trinitroperhydro-1,3,5-triazine, bisphenol A, triclosan, caffeine, carbamazepine, lincomycin, and DEET, in three representative crops, corn, tomato, and wheat. The internal aqueous solution, i.e., sap, is liberated via a freeze/thaw cycle, and separated from macromolecules utilizing molecular weight cutoff membrane centrifugal filtration. Detection limits ranged from 0.01 µg L-1 to 2.0 µg L-1. Recoveries of spiked analytes in three species ranged from 83.7% to 109%. Developed methods can rapidly screen EFCs in agriculture crops and can assess pollutant distribution at contaminated sites and gain insight on EFCs transport in plants to assess transmembrane migration in vascular organisms. The findings contribute significantly to environmental research, food security, and human health, as it assesses the first step of potential entry into the food chain, that being transmembrane migration and plant uptake, the primary barrier between polluted waters or soils and our food.

[Effect of sijunzi decoction on salivary amylase secretion disorder and VIP-cAMP signaling pathway in splenasthenic rats].

OBJECTIVE: To observe the effect of Sijunzi Decoction on secretion disorder of salivary amylase in splenasthenic rat and its mechanism. METHODS: The model group rats received reserpine 0.5 mg/kg through subcutaneous injection while the control group rats received the same volume of saline for 8 days. After being modeled, the model group were divided into treatment group and model control group, treatment group were given orally Sijunzi Decoction, model control group and normal group were fed the same amount of distilled water for 4 weeks. The animal were anaesthetized and the left parotid was removed, the wounds were sutured. When the animals were awake but drowsy, 20 microL 10% glacial acetic acid was applied on the apex of the tongue once a minute for 30 minutes, removed the right parotid gland of the animals. The samples were frozen and amylase activity and VIP, cyclic adenosine monophosphate (cAMP) content and VAMP-8, SNAP-23 protein expression in the parotid glands were detected. RESULTS: Change of sAA in parotid acinar was not significantly different between treatment group and normal groups, but higher in model control groups after acid stimulation. The VIP and PKA contents were not significantly different among three groups. VIP, cAMP content and PKA activity increased significantly in normal group while VIP increased slightly, cAMP and PKA activity decreased in model control groups, which returned to some degrees in treatment group after acid stimulation. Expression of VAMP-8 protein was not significantly different between treatment group and model control groups, while expression of SNAP-23 was lower in model control groups, expression of VAMP-8 and SNAP-23 was higher in treatment group than which in model control groups. CONCLUSION: Sijunzi Decoction has a certain effect on secretion disorder of salivary amylase in splenasthenic rat, which mechanism may be related to recover changes of VIP-cAMP signal pathway in the splenasthenic rat's parotid gland cells,including increase VIP content and expression of VAMP-8 and SNAP-23.