Pressurized Liquid Extraction of Pigments from Chlamydomonas sp.and Chemical Characterization by HPLC–MS/MS

Pressurized liquid extraction using green solvents(ethanol and water)was applied to extract photosynthetic pigments from the microalgae Chlamydomonas sp.An experimental design is employed to determine the effect of the extraction conditions on the extraction yield and the antioxidant capacity of the different extracts determined using 1,1-diphenyl-2-picryl-hydrazyl and TEAC tests.All the extracts show significant antioxidant activity in all assays.Besides,in this work,the carotenoid and chlorophyll composition of the Chlamydomonas extracts was analyzed by HPLC–DAD–APCI–MS/MS for the first time,being the main compounds lutein and pheophythin a′.

Determination of berberine in Phellodendron amurense from different sites of Changbai Mountain

Phellodendron amurense has been used for many years as a medical plant in traditional Chinese medicine and has shown great prospect in recent clinical trials for future applications. Berberine is an essential active compound contained in P. amurense. Our objective in this study was to quantify the content of berberine in P.amurense from sites at different elevations on Changbai Mountain. We collected samples of P. amurense from five different elevations on Changbai Mountain. Berberine in samples was extracted by ultrahigh pressure extraction（UPE）. And the quantity was measured by high performance liquid chromatography（HPLC）. First, the optimal HPLC conditions for berberine were identified with satisfactory precision（relative standard deviation, R SD／5.6 %）, good accuracy（relative error, R E／ 3.6 %） and good linear relation（R2= 0.9998） in the range of 6.576–328.8 mg L-1. Second, the combination of UPE and HPLC methods in quantitative analysis of berberine showed high repeatability（R SD= 3.28 %）, reproducibility（R SD= 4.72 %）,stability（R SD／ 1.27 %） and good recovery（99.54 %） for real plant materials. Samples from Heilongjiang Province at the lowest elevation contained the highest amount of berberine.Similarly, the lowest amount of berberine was recorded in samples from Changbai Forest Bureau of Jilin Province collected at the highest elevation in this paper. The proposed UPE–HPLC method is simple, reliable and low-cost for quantitative analysis of berberine. Content of berberine in P.amurense varied significantly by site on Changbai Mountain.

Quantification of perfluorinated compounds in atmospheric particulate shows potential connection with environmental event

A method of quantification of perfluorinated compounds(PFCs)from atmospheric particulate matter(APM)is described.A single step pretreatment method,selective pressurized liquid extraction(SPLE),was developed to reduce the high matrix background and avoid contamination from commonly used multiple sample pretreatment steps.An effective sorbent was selected to purify the PFCs during SPLE,followed by liquid chromatography-tandem mass spectrometry(LC–MS/MS),for quantification of PFCs.Conditions affecting the SPLE efficiency,including temperature,static extraction time,and number of extraction cycles used,were studied.The optimum conditions were found to be 120℃,10 min,and 3 cycles,respectively.LC-MS/MS method was developed to obtain the optimal sensitivity specific to PFCs.The method detection limits(MDLs)were 0.006 to 0.48 ng/g for the PFCs studied and the linear response range was from 0.1 to 100 ng/g.To ensure accurate values were obtained,each step of the experiment was evaluated and controlled to prevent contamination.The optimized method was tested by performing spiking experiments in natural particulate matter matrices and good rates of recovery and reproducibility were obtained for all target compounds.Finally,the method was successfully used to measure 16 PFCs in the APM samples collected in Beijing over five years from 2015 to 2019.It is observed that some PFCs follow the trend of total PFC changes,and can be attributed to the environment influencing events and policy enforcement,while others don't seem to change as much with time of the year or from year to year.