[Effects of reductive soil disinfestation and organic fertilizer application on microbial community stability in a facility vegetable soil]. / 强还原处理和施用有机肥对设施蔬菜地土壤微生物群落稳定性的影响.

Reductive soil disinfestation (RSD) is an effective method for remediating degraded facility vegetable soils. However, the effectiveness of RSD using green manure as a carbon source in the field has not yet been clarified. We investigated the effects of RSD and organic fertilizer application on soil microbial community composition, diversity, and stability in a degraded facility vegetable soil. There were six treatments, including no fertilization (CK), no fertilization and soil flooded and mulched with plastic film (FF), soil amended with chicken manure (OM), soil amended with chicken manure and flooded and mulched with plastic film (OMR), soil amended with Sesbania cannabina (TF), and soil amended with S. cannabina and flooded and mulched with plastic film (TR). The results showed that the OMR and TR treatments significantly decreased bacterial Chao1 index, altered bacterial and fungal community structure, and increased the relative abundances of Bacillus, Rhodococcus, Clostridium, and Penicillium. The TR treatment significantly reduced the relative abundance of Fusarium. Results of redundancy analysis and Mantel test analysis suggested that soil ammonium nitrogen and dissolved organic carbon contents were the key factors influencing bacterial community composition, and soil pH was the key factor affecting fungal community composition. Results of cohesion analysis showed that the OMR and TR treatments significantly improved bacterial community stability, and that there was no difference between OMR and TR treatments. The TR treatment enhanced fungal community stability, which was significantly higher than the OMR treatment. Therefore, the RSD with green manure as carbon source could be effective remediation practice to improve soil health.

Denitrification process of Casuarina root nodule endophyte Frankia.

To examine the characteristic of denitrification in Frankia, a symbiotic nitrogen-fixing microbe associated with non-leguminous plants, and its role as a N2O source or sink, Casuarina root nodule endophyte Frankia was isolated using sectioning method, which was then purely cultured to investigate the denitrification process under NO3- addition. The results showed that after addition of NO3- to the medium under anaerobic condition, the concentration of NO3- decreased with time, while the concentrations of NO2- and N2O initially increased and then decreased over time. Key denitrification genes and nitrogenase gene were detected at 26 h, 54 h and 98 h during incubation. Abundances of these genes significantly differed among each other, and their dynamics were asynchronous. Redundancy analysis of the effect of NO3-, NO2-, N2O concentrations on abundances of denitrification genes and nitrogenase gene indicated that 81.9% of the total variation in gene abundances could be explained by the first two axes. Frankia had a denitrifying activity under anaerobic condition, with denitrification genes, including nitrous oxide reductase gene (nosZ), being identified. Our results suggested that Frankia possessed a complete denitrification pathway and the ability of N2O reduction under anaerobic condition.

[Effects of Feedstock Material and Pyrolysis Temperature on Dissolved Organic Matter in Biochars].

The aim of this study was to investigate the effects of feedstock material and pyrolysis temperature on the content and spectral properties of dissolved organic matter(DOM) in biochars. Biochars were produced from the pyrolysis of rice straw and Cunninghamia lanceolata litter at three temperatures(350, 500, and 650℃). The results showed that the pH values of the two biochars with pyrolysis temperature increases were improved from 8.10 and 6.56 to 10.53 and 8.23, respectively. The pyrolysis temperature had no significant effect on the total C content of biochar, but the feedstock material and their interaction had significant effects on the total C content of the biochar(P<0.05). The dissolved organic carbon(DOC) content of the two types of biochar first decreased and then increased with increasing pyrolysis temperature, and the content of DOC of the biochar derived from rice straw was significantly higher than that from Cunninghamia lanceolata litter under the same temperature(P<0.05). The feedstock material had no significant effect on the SUVA254 value of DOM, but temperature and its interactive effect with the feedstock material had a significant effect on the SUVA254 values(P<0.05). Maximum DOC SUVA254 values occurred at 500℃ in the two types of biochar, indicating the highest degree of aromatization. Three-dimensional fluorescence spectra showed that the DOM components of the two types of biochar were dominated by fulvic acid-like and humic acid-like material, which had different responses to pyrolysis temperature. FTIR spectra suggested that the DOM of the biochars had absorption peaks at similar positions, in five regions, and the stretching vibration of aliphatic C-H gradually weakened with an increase in pyrolysis temperature. Therefore, the biochars produced at higher pyrolysis temperatures(500℃ and 650℃) had lower DOC contents but a higher aromatization degree and humification degree, and were more stable, compared to the biochars produced at a lower pyrolysis temperature(350℃).

Discovery of chemical markers for identifying species, growth mode and production area of Astragali Radix by using ultra-high-performance liquid chromatography coupled to triple quadrupole mass spectrometry.

BACKGROUND: Astragali Radix (AR) is a well-known Chinese herbal medicine. The quality of AR can be affected by many factors such as species, growth mode and production area, but there are still no chemical markers to distinguish it. PURPOSE: To explore chemical markers for improving the quality assessment of AR and discover chemical markers for identifying species, growth mode and production area of AR. METHODS: A highly sensitive, efficient and accurate method based on ultra-high performance liquid chromatography coupled to triple quadrupole mass spectrometry (UHPLC-QQQ-MS/MS) for simultaneous quantitative determination of 14 major chemical components (five flavonoids and nine triterpene saponins) in 94 batches of AR from China, Republic of Korea and Germany was developed for the first time. To explore chemical markers and assess changes in the contents of 14 compounds in the 94 batches of AR samples from different regions, hierarchical clustering analysis (HCA) and principal component analysis (PCA) were performed. RESULTS: Astragaloside III was not only an important chemical marker for distinguishing two species of AR, i.e.: Astragalus mongholicus and A. membranaceus, but also a potential chemical marker for the classification of cultivated and semi-wild AR. In addition, in the batches of cultivated AR, the content of isoastragaloside II and cyclocephaloside II were greater in batches from the region of Shaanxi Province than that of other Provinces in China, but the content of calycosin-7-O-ß-D-glucoside and astragaloside IV, which are the quality control markers of AR required by the Chinese Pharmacopoeia, were higher than that of other Provinces in China. In addition, the content of calycosin-7-O-ß-D-glucoside, ononin, calycosin and astragaloside I could be used to identify samples of AR collected from China, Republic of Korea and Germany. CONCLUSION: This UHPLC-QQQ-MS/MS method could be applied to the quantitative evaluation of AR and could be an important and meaningful reference to develop chemical markers for quality control of AR.

[Effects of litter removal and nitrogen addition on carbon and nitrogen in different soil fractions in a subtropical broad-leaved forest.] / å‡‹è½ç‰©åŽ»é™¤å’Œæ°®æ·»åŠ å¯¹äºšçƒ­å¸¦é˜”å¶æž—åœŸå£¤ä¸åŒç»„åˆ†ç¢³ã€æ°®çš„å½±å“.

The increasing nitrogen deposition due to human activities has impacted forest ecosystems to a large extent. The organic carbon and nitrogen released from decomposing litters play an important role in the formation, stability and transformation of soil organic carbon and nitrogen. We collected soil samples from a subtropical evergreen broadleaved forest experiment with nitrogen deposition [control (0), LN (75 kg·hm-2·a-1), HN (150 kg·hm-2·a-1)] and litter control (litter retained and litter removal) for eight years. After extracted by solution of K2SO4, Na2B4O7, Na4P2O7, NaOH, H2SO4, Na2S2O4 and HF step by step, carbon and nitrogen in each extraction was analyzed. The results showed that overall most of soil carbon and nitrogen existed in the Humin fraction, accounting for 33.5% of the total carbon and 33.3% of the total nitrogen. The soluble total carbon and nitrogen extracted by Na2B4O7 solution was the highest, followed by NaOH and Na4P2O7 solution. The soluble total carbon, soluble total nitrogen and soluble organic nitrogen of soil extracted by three reagents accounted for 46.2%, 47.9%, and 76.5% of the total extractions, respectively. In addition, nitrogen addition significantly increased carbon and nitrogen content in Na2S2O4 and Humin fractions. Litter removal reduced carbon content in Na2B4O7, H2SO4, Na2S2O4 and Humin fractions, and nitrogen content in NaOH, HF and Humin fractions. The nitrogen content in the K2SO4 extraction was significantly increased by both litter remained and nitrogen addition. Our results demonstrated that litter and nitrogen added could mutually affect carbon and nitrogen concentration of soil fractions with different chemical stability, with consequences on the process of soil carbon and nitrogen.

Continuous-wave difference-frequency generation based on BaGa4Se7 crystal.

A continuous-wave mid-infrared radiation from difference frequency generation by mixing a continuous-wave Ti: sapphire laser and a continuous-wave YAG laser in a 15 mm long BaGa4Se7 crystal is demonstrated for the first time. The tunable range from 3.15 to 7.92 µm was achieved by rotating the crystal to fulfill the type I phase-matching condition. A maximum DFG power of 1.41 µW was obtained at 5 µm. Meanwhile the experimental DFG power conversion efficiency was 20.2 µW/W2, with a length-normalized slope efficiency of 15.5 µW/cmW2. The conversion efficiency decreases rapidly from 50 µW/cmW2 at 3.15 µm to 1 µW/cmW2 at 7.92 µm. The wavelength acceptance bandwidth and the angular acceptance bandwidth were measured to be 16.4 cm-1 and 44' for DFG at 5.1 µm, respectively.

Mechanisms of wheat (Triticum aestivum) grain storage proteins in response to nitrogen application and its impacts on processing quality.

Basis for the effects of nitrogen (N) on wheat grain storage proteins (GSPs) and on the establishment of processing quality are far from clear. The response of GSPs and processing quality parameters to four N levels of four common wheat cultivars were investigated at two sites over two growing seasons. Except gluten index (GI), processing quality parameters as well as GSPs quantities were remarkably improved by increasing N level. N level explained 4.2~59.2% and 10.4~80.0% variability in GSPs fractions and processing quality parameters, respectively. The amount of N remobilized from vegetative organs except spike was significantly increased when enhancing N application. GSPs fractions and processing quality parameters except GI were only highly and positively correlated with the amount of N remobilized from stem with sheath. N reassimilation in grain was remarkably strengthened by the elevated activity and expression level of glutamine synthetase. Transcriptome analysis showed the molecular mechanism of seeds in response to N levels during 10~35 days post anthesis. Collectively, we provided comprehensive understanding of N-responding mechanisms with respect to wheat processing quality from N source to GSPs biosynthesis at the agronomic, physiological and molecular levels, and screened candidate genes for quality breeding.

[Effects of storage temperature and time on the contents of different nitrogen forms in fresh soil samples.] / æ–°é²œåœŸå£¤æ ·å“å‚¨å­˜æ¸©åº¦å’Œæ—¶é—´å¯¹ä¸åŒå½¢æ€æ°®ç´ çš„å½±å“.

Soil nitrogen forms and contents are of great importance in ecological studies. The storage methods of soil samples have great effects on the accuracy of determination of nitrogen contents. We aimed to select a reasonable storage method for soil samples with forest soil of Castanopsis faberi fore-st at Wanmulin Nature Reserve in Jian'ou City as an example. The contents of soil ammonium, nitrate, total nitrogen, soluble organic nitrogen, amino acid nitrogen and microbial biomass nitrogen were measured in soil samples under the storage conditions of different temperature (at 25, 4 and -20 ℃) and different times (0, 7 and 30 days). The nitrogen contents during the process of cultivating under the room temperature after being frozen were also measured. The results showed that the contents of all nitrogen forms except for amino acid nitrogen were increased in the soil samples that stored at the room temperature for seven days. There were no significant differences between the contents of all the tested nitrogen forms in the refrigerated or frozen samples and the fresh soil samples. The changes of nitrogen content in soil samples at refrigerated and frozen storage were more stable than those at room temperature storage. The low temperature storage could stimulate soil mineralization. Hence, after stored for 30 days, contents of all the tested nitrogen forms in the refri-gerated and frozen storage soil samples were significantly higher than those in the fresh samples except for the soluble organic nitrogen, whereas there was no significant difference between the refrigerated and frozen storage methods. Therefore, fresh samples should be promptly processed when taken back to the laboratory. If the samples needed to storage, it should not be stored more than half a month. If the samples need a longer storage time, it must be placed in lower temperature (at -40 or -80 ℃). Pre-incubation treatment was required when the low temperature storage soil sample was subjected to an experiment. In the process of pre-incubation, the contents of all the tested nitrogen form in soil samples gradually approached the level of fresh soil sample with the increases of incubation time except for that of nitrate which decreased firstly and then increased rapidly. After incubation for about one week, the nitrogen content of soil sample returned to the level that was close to that of the fresh soil. In combination with studies previously reported, soil samples collected from field and air dried samples needed a pre-incubation for 5-14 days, and the pre-incubation time for the cold storage sample should not be less than one week.

[Effects of biochar addition on the mineralization of native soil organic carbon in Cunninghamia lanceolata plantation.] / ç”Ÿç‰©è´¨ç‚­æ·»åŠ å¯¹æ‰æœ¨äººå·¥æž—åœŸå£¤åŽŸæœ‰æœ‰æœºç¢³çŸ¿åŒ–çš„å½±å“.

Effects of addition of different biochars on soil organic carbon (SOC) mineralization were studied by the 13C-labelling technique for a better understanding of biomass resource utilization and carbon sequestration in subtropical Chinese fir (Cunninghamia lanceolata) plantation. An incubation experiment under 25 ℃ was performed over a period of 112 days to address how different biochar addition would affect the mineralization of native SOC. Biochars were produced from Schimasuperba or C. lanceolata litter at 350, 550 and 750 ℃, respectively. Results showed that the mineralization of native SOC was significantly accelerated during the first three days and subsequently suppressed from 7 to 112 days of incubation after C. lanceolata biochar addition compared to the control. In the S. superba biochar addition treatment, there was a significant increase in mineralization of native SOC within the first 14 days of incubation and then a rapid decrease from days 28 to 112. After 112 days incubation, all the three C. lanceolata biochar (350, 550 and 750 ℃) additions significantly inhibited the mineralization of native SOC. A similar trend was observed for the two S. superba biochar (350 and 550 ℃) additions but not for the S. superba biochar (750 ℃) addition. The decomposition rates of S. superba biochar and C. lanceolata biochar were 0.8%-2.8% after 112 days incubation and decreased with the increases of pyrolysis temperature. Under the same pyrolysis temperature, the decomposition rate of the S. superba biochar was significantly higher than that of the C. lanceolata biochar. In conclusion, both the raw material and pyrolysis temperature of biochars would be important factors driving the mineralization of native SOC and biochar degradation.

Rapid authentication of starch adulterations in ultrafine granular powder of Shanyao by near-infrared spectroscopy coupled with chemometric methods.

Near-infrared reflectance (NIR) spectroscopy combined with chemometric techniques was developed for classification and quantification of cheaper starches (corn and wheat starch) in ultrafine granular powder of Shanyao (UGPSY). By performing orthogonal partial least squares discrimination analysis (OPLS-DA), NIR could efficiently distinguish among authentic UGPSY and UGPSY adulterated with cornstarch and wheat starch. In addition, the starch content in adulterated UGPSY was determined by NIR coupled with an appropriate multivariate calibration method. Partial least squares (PLS), interval PLS (iPLS) and synergy interval PLS (siPLS) algorithms were performed comparatively to calibrate the regression model. Experimental results showed that the performance of the siPLS model is the best compared to PLS and iPLS. These results show that the combination of NIR spectroscopy and chemometric methods offers a simple, fast and reliable method for the classification and quantification of the ultrafine granular powder of the herb.

[Effects of water-soluble organic matter and residue of litter on nitrogen transformation in subtropical forest soil.] / å‡‹è½ç‰©ä¸­æ°´æº¶æ€§æœ‰æœºç‰©å’Œæ®‹æ¸£å¯¹äºšçƒ­å¸¦æ£®æž—åœŸå£¤æ°®ç´ è½¬åŒ–çš„å½±å“.

An incubation experiment was carried out with the addition of litter filtrate, litter residue and alanine at 25 ℃ for 36 days under 60% and 90%WHC (water holding capacity) conditions. The results showed that alanine was rapidly mineralized in soil, and soil NH4+-N content significantly increased by 5.4%-44.7% and 16.1%-41.3%, respectively under 60% and 90%WHC conditions compared with the control. The soil net nitrogen mineralization and ammonification rates in the two treatments were also higher than those in the control at the early stage of incubation. However, the soil NH4+-N content was reduced by the addition of filtrate and residue, and the reduction degree of residue was greater. During the incubation, soil NO3--N content showed a linear increasing trend with the incubation time, and it was significantly higher under the 60%WHC condition than that under 90%WHC condition at the end of incubation. The mineralization of soil organic matter was limited by higher soil moisture. Therefore, the soil soluble organic carbon (SOC) content under 90%WHC condition was obviously lower than that under 60%WHC, but nitrous oxide (N2O) emission was 1.5-63.0 times higher than that under 60%WHC. Furthermore, N2O emission was induced significantly by the addition of litter residue under 60%WHC condition. These results indicated that there were different effects of soluble matter and litter residue on soil nitrogen transformation, and these differences would change dynamically in the decomposition process.

[Soil microbial community structure of two types of forests in the mid-subtropics of China].

Soil microbial community structures were analyzed by biomarker method of phospholipid fatty acid (PLFA) for a natural forest dominated by Castanopsis fabri (CF) and an adjacent plantation of Cunninghamia lanceolata (CL) in the mid-subtropics of China. The results showed that the amounts of total PLFAs, bacterial PLFAs, fungal PLFAs, gram-positive bacterial PLFAs and gramnegative bacterial PLFAs in the 0-10 cm soil layer were higher than in the 10-20 cm soil layer, and each type of PLFAs in CF were higher than in CL. In either soil layer of the two forest types, the contents of bacterial PLFAs were significantly higher than those of fungal PLFAs. In the two forests, the contents of bacterial PLFAs accounted for 44%-52% of total PLFAs, while the contents of fungal PLFAs just accounted for 6%-8%, indicating the bacteria were dominant in the soils of the two vegetation types. Principal component analysis showed that the influence of vegetation types was greater than soil depth on the microbial community structures. Correlation analysis showed that gram-negative bacterial PLFAs, gram-positive bacterial PLFAs and bacterial PLFAs were significantly negatively correlated with pH, positively with water content, and the PLFAs of main soil microorganism groups were significantly positively correlated with soil total nitrogen, organic carbon, C/N and ammonium.

[Effects of water levels and the additions of different nitrogen forms on soil net nitrogen transformation rate and N2O emission in subtropical forest soils].

An incubation experiment was conducted to investigate the effects of the additions of different nitrogen forms on nitrogen transformation in red soils of subtropical forest under soil moisture conditions with 40%, 70% and 110% of water holding capacity (WHC). The results showed that soil net mineralization and ammonification rates were maximum at 70% WHC and minimum at 40% WHC. Compared with the control, the addition of NO(3-)-N decreased the soil net mineralization and ammonification rates by 56.1% and 43.0% under 70% WHC condition, and decreased by 68.2% and 19.0% under 110% WHC, respectively. However, the proportion of ammonification to mineralization increased at 70% and 110% WHC, which suggested that nitrate addition inhibited the nitrification. With addition of NO(3-)-N at 110% WHC, the net nitrification rate was lowest while N20 emission was highest with the concomitant decrease of nitrate content, indicating that N2O emission was largely derived from denitrification. However, at 40% WHC and 70% WHC, the maximum N20 flux was found at the early stage of incubation. Even with addition of NH(4+)-N and NO(3-)-N, N2O flux did not change much at the latter stage of incubation, indicating that autotrophic nitrification was dominant for N20 production at the early stage of incubation. Under 40% WHC condition, soluble organic carbon increased more and it increased largely with NH(4+)-N addition, which meant NH(4+)-N addition could enhance the mineralization of soil organic matter. Under 40% and 110% WHC conditions, the addition of NH(4+)-N increased significantly the soil soluble organic nitrogen (SON) by 73.6% and 176.6% compared with the control, respectively. A significant increase of 78.7% for SON was only found at 40% WHC under addition of NO(3-)-N compared with the control. These results showed that high soil moisture condition and addition of NH(4+)-N were of benefit to SON formation.

[Effects of low temperature on dormancy breaking and growth after planting in bulbs of Tulipa edulis].

The effect of low temperature storage on dormancy breaking, sprouting and growth after planting of Tulipa edulis was studied. The results showed that starch content and activity of amylases significantly decreased during 10 weeks of cold storage, soluble protein content raised at first then decreased, and the peak appeared at the 6th week. However, total soluble sugar content which in- creased slowly at first than rose sharply and reducing sugar content increased during the storage duration. The bulbs with cold storage treatment rooted in the 6th week, which was about 2 weeks earlier than room temperature storage, but there were less new roots in the late period of storage. After stored at a low temperature, bud lengths were longer than that with room temperature treatment. Cold storage treatment could promote earlier emergence, shorten germination time, prolong growth period and improve the yield of bulb, but rarely affect the emergence rate. It was not beneficial to flowering and fruiting. The results indicated that 6-8 weeks of cold storage was deemed to be the key period of dormancy breaking preliminary.

[Effects of L-methionine on nitrification and N2O emission in subtropical forest soil].

The objective of this study was to investigate the influence of L-methionine on nitrification and nitrous oxide emission in a red soil under laboratory incubation experiments. A subtropical broad-leaved forest soil sample was collected from Wanmulin natural reserve in Fujian Province, Southeast China. Five treatments were carried out with three replications, i. e., control (CK), L- methionine addition (M), L-methionine and NH(4+)-N addition (MA), L-methionine and NO(2-)-N addition (MN), L-methionine and glucose addition (MC). The soil moisture was maintained at 60% WHC or 90% WHC. The results indicated that the soil NH(4+)-N content in the M treatment significantly increased by 0.8%-61.3%, while the soil NO(3-)-N content reduced by 13.2%-40.7% compared with CK. Under 60% WHC condition, soil NO(2-)-N content in the MC treatment was higher than in the M treatment, soil NO(3-)-N content in the MA and MN treatments were greater than that in the M treatment, and greater in the MN treatment than in the MA treatment. The soil NO(3-)-N content was lowest in the M treatment after incubation. These results suggested that L-methionine could inhibit nitrosation process of autotrophic nitrification. To some extent, carbon addition as glucose with L-methionine decreased the NH(4+)-N content, inhibited the autotrophic nitrification and their effects were dependent on water level. Under 90% WHC condition, carbon addition improved denitrification more obviously, but the decrease of NO(3-)-N content was not sufficient to prove the inhibition of hetero-nitrification due to carbon addition in the presence of L-methionine. The nitrous oxide emission from soil was increased by L-methionine addition. Compared with 60% WHC condition, the nitrous oxide emission was higher under 90% WHC condition, and the promotion of L-methionine addition on N2O was greater when glucose added.

[Effects of flower bud removal and artificial pollination on growth and yield of Tulipa edulis].

The study was conducted to explore the response of growth and yield of Tulipa edulis to flower bud removal and artificial pollination. And flower bud removal and artificial pollination were carried out in the squaring period and bloom stage respectively. The morphological index and biomass indicators were determined and the yield was counted in harvest time. Result showed that flower bud removal was beneficial to the growth of T. edulis, resulting in increasing growth index, biomass as well as the yield of bulb. The diameter and dry weight of T. edulis fruit by artificial pollination were increased significantly compared with the control. Seed setting percentage increased to 100%, and the number of seed as well as the single grain weight increased by 69.03% and 16.48%, respectively, which did not significantly affect the bulb production. In conclusion, Flower bud removal treatment accelerates bulb biomass increase, so as to improve its yield. Artificial pollination raised significantly seed setting percentage, seed number as well as the single grain weight.

[Measurement and application of CO2 spectroscopic parameters near 2.0 µm].

The accuracy of absorption spectral parameters is very important for the trace gas measurement based on absorption spectroscopy techniques, especially for the isotopic abundance measurement of gas molecules. For some of the applications, spectral parameters listed in HITRAN database were used to retrieve the trace gas concentration. However, these parameters have uncertainty, in order to validate spectroscopic parameters near 2.0 µm of CO2 lines, which are to be used in detecting the CO2 concentration and isotopic abundance, spectra of those lines were recorded at room temperature using a distributed feed-back (DFB) diode laser. The recorded absorption spectra were fitted to Voigt profile. Line position, intensity, self-broadening coefficient and N2-broadening coefficient were deduced from those data. The results show a good consistency in comparison with those listed in HITRAN2012 database. The discrepancy of most line intensities and self-broadening coefficients are less than 2%. The CO2 concentration and Δ(13 CO2 ) in real atmosphere inside laboratory are 440 ppm and -9 per hundred respectively. These results provide a reliable basis for real time and on line detecting the CO2 concentration and Δ(13 CO2) in the wavelength range.

[Quality evaluation of Astragali Radix through chemical pattern recognition of fingerprint by HPLC-dAD-ELSD].

OBJECTIVE: To develop an HPLC-DAD-ELSD method for detecting the fingerprint of Astragali Radix and evaluate the quality through similarity calculation and chemical pattern recognition. METHOD: Separation was performed at 25 degreeC on an Agilent Zorbax ODS C18 column(4.6 mm x250 mm,5 microm). Gradient elution was performed with the mobile phases of acetonitrile and water containing 0. 2% formic acid. The flow rate was 0. 8 mL min-1 , and sample size was 10 microL. The UV detection wavelength was set at 280 nm. The drift tube temperature for ELSD was set at 110 degreeC , and the nebulizing gas flow rate was 3.0 L min-1. The similarity calculation and chemical pattern recognition were used for fingerprint analysis. RESULT: The HPLC-DAD-ELSD method for chromatographic fingerprint of Astragali Radix showed better results of stability, precision and repeatability. The reference chromatographic fingerprint of Astragali Radix was established on the eighteen Astragali Radix samples from different sources. The results of similarity calculation were higher than 0. 83, which was in accordance with the result of chemical pattern recognition analysis. CONCLUSION: Fingerprint and chemical pattern recognition analysis could effectively distinguish Astragali Radix from different source, which could be applied to the quality control of Astragali Radix.

[Effects of litters and tannin on forest soil inorganic nitrogen].

A laboratory incubation test was conducted to study the effects of litters and tannin on forest soil nitrate- and ammonium N. The addition of litters and tannic acid made the soil nitrate- and ammonium N decreased. With the addition of fir litter, the nitrate- and ammonium N contents in red soil decreased by 6.1%-25. 9% and 19.7%-68.6%, respectively, and the decrements in yellow-red soil were higher than those with the addition of bamboo litter, being significant for ammonium N. Compared with the control, the addition of tannin decreased the ammonium N content in yellow-red soil significantly, and there was a positive correlation between the concentration of added tannin and the decrement of soil ammonium N content. When the concentration of added tannin was high, the decrement of the ammonium N reached 31.9%-57.8%. With the addition of low concentration tannin, the soil nitrate N content decreased with time, and the decrement on the 84th day reached 4.5%. However, the addition of high concentration tannin increased the soil nitrate N content by 10.3%-18.5% in the first 7-28 days, but decreased it by 23.9% and 42.3% on the 56th and 85th day, respectively.

Simultaneous determination of iridoids, phenolic acids, flavonoids, and saponins in Flos Lonicerae and Flos Lonicerae Japonicae by HPLC-DAD-ELSD coupled with principal component analysis.

A method, HPLC coupled with diode-array and evaporative light scattering detectors (HPLC-DAD-ELSD), was newly developed to evaluate the quality of Flos Lonicerae (FL) and Flos Lonicerae Japonicae (FLJ), through a simultaneous determination of multiple types of bioactive components. By employing DAD, the detection wavelengths were set at 240 nm for the determination of iridoids, 330 nm for phenolic acids, and 360 nm for flavonoids, respectively. While ELSD, connected in series after DAD, was applied to the determination of saponins. This assay was fully validated with respect to precision, repeatability, and accuracy. Moreover, principal component analysis (PCA) was used for the similarity evaluation of different samples, and it was proven straightforward and reliable to differentiate FL and FLJ samples from different origins. For PCA, two principal components have been extracted. Principal component 1 (PC1) influences the separation between different sample sets, capturing 54.598% variance, while principal component 2 (PC2) affects differentiation within sample sets, capturing 12.579% variance. In conclusion, simultaneous quantification of bioactive components by HPLC-DAD-ELSD coupled with PCA would be a well-acceptable strategy to differentiate the sources and to comprehensively control the quality of the medicinal plants FL and FLJ.