The Determination of Canthaxanthin in Feed Ingredients by High Performance Liquid Chromatography

A series of studies were conducted to establish a methodology for the accurate and efficient determination of canthaxanthin in feed ingredients. Agilent ZORBAX Eclipse DB-C 18 analytical column （4.6×150 mm, 5μm） was used and kept at 25 ℃. The mobile phase was acetonitrile ： methanol （v/v）=95 ： 5, and eluted compounds were detected by DAD absorbance （470 nm）. The flow rate was maintained at 1.0 mL·min^-1. The response of the method was linear over the range 1.0-20.0 μg·mL^-1 canthaxanthin assay solution （R^2=0.9998）. Recovery assays done with standard canthaxanthin to feed ingredient resulted in an average recovery of 103%. Variation coefficient was less than 3.53%. This method is proved to be simple, precise, sensitive and reproductive.     

Dissipation and residue of ethephon in maize field

A rapid and reliable method was developed for analysis of ethephon residues in maize, in combination with the investigation of its dissipation in field condition and stabilities during the sample storage. The residue analytical method in maize plant, maize kernel and soil was developed based on the quantification of ethylene produced from the derivatization of ethephon residue by adding the saturated potassium hydroxide solution to the sample. The determination was carried out by using the head space gas chromatography with flame ionization detector(HS-GC-FID). The limit of quantification(LOQ) of the method for maize plant was 0.05, 0.02 mg kg–1 for maize kernel and 0.05 mg kg–1 for soil, respectively. The fortified recoveries of the method were from 84.6–102.6%, with relative standard deviations of 7.9–3.8%. Using the methods, the dissipation of ephethon in maize plant or soil was investigated. The half life of ethephon degradation was from 0.6 to 3.3 d for plant and 0.7 to 5.7 d for soil, respectively. The storage stabilities of ethephon residues were determined in fresh and dry kernels with homogenization and without homogenization process. And the result showed that ethephon residues in maize kernels were stable under –18°C for 6 mon. The results were helpful to monitor the residue dissipation of ethephon in the maize ecosystem for further ecological risk assessment.     

Study on HPLC method to determine contents of Schisandrin A and Schisandrin B in Schisandra chinensis extraction

The determination method of Schisandrin A and Schisandrin B in Schisandra chinensis was improved with the high performance liquid chromagraphy(HPLC).The sample was extracted exceedingly in the critical limit of CO 2 .The retention time of Schisandrin A and Schisandrin B was reduced,with methano/water(75:25)as mobile phase.The wavelength for detection was 254 nm. The R2 of standard curve was 0.9998 and the relative standard deviation was 2.31%and 3.17%with the recovery of 96.45%and 97.37%,respectively.The result shows that the rate of veracity of this method is higher and it proves that the determination method of Schisandrin A and Schisandrin B in Schisandra chinensis is a feasible method.     

共振瑞利散射法测定水产品中孔雀石绿

在pH=4.4的HC1-NaAc缓冲介质中,孔雀石绿(MG)以及钨酸盐溶液自身的共振瑞利散射(RRS)均十分微弱.但是当MG染料阳离子与钨酸根(WO42-)形成离子缔合物时,RRS急剧增强,并出现新的RRS光谱,其RRS峰分别位于339 nm,451 nm和591 nm处.在最大散射波长339 nm处.孔雀石绿浓度在0.060～2.8 μg/mL范围与散射增强(ΔⅠ)呈良好线性关系,因此可用于痕量孔雀石绿的测定.方法灵敏度高,检出限为18.1 ng/mL.本法用于鱼肉中孔雀石绿残留量的测定,结果满意.

Abstract：

In an experiment reported in this paper, the resonance Rayleigh scattering (RRS) of malachite green (MG) or tungstate anion was very weak in pH 4.4 HC1-NaAc buffer medium, but when MG cation reacted with WO42- anion to form an ion association complex, its RRS dramatically increased and a new RRS spectrum appeared with the RRS peaks at 339 nm, 591 nm and 451 nm. The intensity of RRS (ΔⅠ)was directly proportional to the concentration of malachite green in the range of 0.06-2.78 μg/mL at the maximum scattering peak of 339 nm. The method was shown to be sensitive and the detection limit for MG was 18.1 ng/mL. Thus a new method for the determination of MG was developed. When applied to the determination of malachite green residues in the flesh of fish, this method gave satisfactory results similar to those of the HPLC method.     

A Novel and Reliable Spectrophotometric Method for Determination of Lactoperoxidase Activity in Raw Milk

With 3, 3'5, 5'-tetramethylbenzidine(TMB) as the detection substrate, a reliable and highly selective method was established and optimized for the determination of Lactoperoxidase(LP) activity in raw milk. The method was based on the enzymatic reaction principle, where hydrogen peroxide oxidated TMB in the presence of LP. The optimized conditions of this assay system were obtained, consisting of 20 mmol · L~(-1) TMB solution, 0.6 mmol · L~(-1) hydrogen peroxide and 0.1 mol · L~(-1) Citric Acid(CA)/0.2 mol · L~(-1) disodium hydrogen phosphate(Na P) buffer(pH 4.8). TMB detection method was applied to the analysis of LP in milk samples with a practical working concentration range from 2 to 14 mg · L~(-1). The intra-and inter-batch variation coefficients were all below 5%, indicating a good repeatability. Confirmation test between TMB method and 2, 2-azinobi(3-ethylbenzothiazoline-6-sulphonate) diammonium salt(ABTS) method was carried out, and the results of TMB assay were in accordance with that of ABTS method.     

Oxygen Transfer Rate of Shaoxing Rice Wine Jars

Traditional Shaoxing rice wine was stored in the pottery jar for aging because the jar are porous and allow oxygen in the air to permeate into the wine,and oxygen plays a key role in the wine aging as it affects the color,aroma and stability of the wine.In this paper we evaluated how much oxygen penetrated into the pottery jar during the rice wine storage.Iron(Ⅱ)solution as the reducing agent was stored in Shaoxing rice wine jars for 30 days.During this period some iron(Ⅱ)was oxidized into iron(Ⅲ)by the oxygen penetrated into the pottery jars.The mass concentrations of the iron(Ⅲ)were determined by a KSCN colorimetric method,thus the oxygen transfer rate(OTR)of the pottery jars was calculated.The result showed that the OTR value is 0.106mg/L per day,and this value is an important reference for designing the large stainless container with micro-oxygeneration devices for Shaoxing rice wine.     

Pretreatment of Rice Straw by Hydrogen Peroxide for Enhanced Methane Yield

A pretreatment process for hydrogen peroxide (H2O2) was optimized to enhance the biodegradation performance of rice straw and increase biogas yield. A determination experiment was conducted under predicted optimal conditions. Optimization was implemented using response surface methodology. The effects of biodegradation and the interactive effects of pretreatment time (PT), H2O2 concentration (HC), and substrate to inoculum ratio (S/I) on methane yield were investigated. The lignin, cellulose, and hemicellulose of rice straw were significantly degraded with increasing HC. The optimal conditions for the use of pretreated rice straw in anaerobic digestion were a 6.18-d PT, 2.68% HC (w/w total solid), and 1.08 S/I; these conditions result in a methane yield of 288 mL g-1 volatile solids (VS). A determination coefficient of 95.2% was obtained, indicating that the model used to predict the anabolic digestion process has a favorable fit with the experimental parameters. The determination experiment resulted in a methane yield of 290 mL g-1 VS, 88.0% higher than that of untreated rice straw. Thus, H2O2 pretreatment of rice straw can be used to improve methane yields during biogas production.     

Effects of Rest Grazing on Organic Carbon Storage in Stipa grandis Steppe in Inner Mongolia,China

This study was aimed to evaluate the potential effects of rest grazing on organic carbon storage in Stipa grandis steppe of Inner Mongolia, China. Using potassium dichromate heating method, we analyzed the organic carbon storage of plant and soil in Stipa grand＆ steppe after rest grazing for 3, 6, and 9 yr. The results indicated that as the rest grazing ages prolonged, the biomass of aboveground parts, litter and belowground plant parts （roots） of the plant communities all increased, meanwhile the C content of the biomass increased with the rest grazing ages prolonging. For RG0, RG3a, RG6a, and RG9a, C storage in aboveground vegetation were 60.7, 76.9, 82.8 and 122.2 g C m2, respectively; C storage of litter were 5.1, 5.8, 20.4 and 25.5 g C m^-2, respectively; C storage of belowground roots （0-100 cm） were 475.2, 663.0, 1 115.0 and 1 867.3 g C m^-2, respectively; C storage in 0-100 cm soil were 13.97, 15.76, 18.60 and 32.41 kg C m^-2, respectively. As the rest grazing ages prolonged, the organic C storage in plant communities and soil increased. The C storage ofbelowground roots and soil organic C was mainly concentrated in 0-40 cm soil body. The increased soil organic C for RG3a accounted for 89.8% of the increased carbon in vegetation-soil system, 87.2% for RG6a, and 92.6% for RG9a. From the perspective of C sequestration cost, total cost for RG3a, RG6,, and RG9a were 2 903.4, 5 806.8 and 8 710.2 CNY haq, respectively. The cost reduced with the extension of rest grazing ages, 0.15 CNY kg^-1 C for RG3a, 0.11 CNY kg-~ C for RG6a and 0.04 CNY kg℃ for RG9a. From the growth characteristics of grassland plants, the spring was one of the two avoided grazing periods, timely rest grazing could effectively restore and update grassland vegetation, and was beneficial to the sustainable use of grassland. Organic C storage for RG9a was the highest, while the cost of C sequestration was the lowest. Therefore, spring rest grazing should be encouraged because it was proved to be a very efficient grassland use pattern.     

钯(Ⅱ)-盐酸吗啉胍螯合物与卤代荧光素染料相互作用的超瑞利散射光谱及其分析应用研究

在pH=4.4～5.0的HAc-NaAc介质中,钯(Ⅱ)与盐酸吗啉胍(Abob)反应形成螯合阳离子,它能进一步与二溴荧光素(DBF)、曙红Y(EY),赤藓红(Ery)阴离子反应形成离子缔合物,引起超瑞利散射(HRS)显著增强.3个三元体系具有相似的光谱特征,最大HRS波长位于390 nm附近.在一定条件下超瑞利散射增强(△IHRS)与Abob的浓度成正比,其线性范围是0.029～3.0μg/mL(DBF),0.14～3.5μg/mL(EY)和0.23～1.9μg/mL(Ery),检出限分别为0.008 6μg/mL(DBF),0.043 μg/mL(EY)和0.069μg/mL(Ery).研究了HRS法的适宜反应条件和共存物质的影响,发展了高灵敏、简便快速测定Abob的新方法,可用于尿样中Abob的测定.

Abstract：

In an acidic medium with pH = 4.4-5.0, palladium (Ⅱ) chelated with moroxydine hydrochloride to form the cation [ Pd (Abob)]2+ , which reacted further with dibromofluorescein (DBF), eosin Y (EY)and erythrosin(Ery) to form ion-association complexes, respectively. As a result, the hyper Rayleigh scattering(HRS) intensities were enhanced greatly. The maximum HRS peak of the three systems was all located at approximately 390 nm. HRS intensity was proportional to the concentration of moroxydine hydrochloride (Abob) in the range of 0. 029-3.0 μg/mL for DBF, 0. 14-3.5 μg/mL for EY and 0.23-1.9 μg/mL for Ery, and their detection limit (3σ) was 0. 008 6, 0. 043 and 0. 069μg/mL, respectively. The optimum conditions of the reaction and the properties of analytical chemistry were investigated. Therefore, a new method for the determination of moroxydine hydrochloride(Abob) by HRS was developed. The method has high sensitivity and good selectivity and has been applied to the determination of Abob in uric samples with satisfactory results.     

RP-HPLC同时测定口服液中的咖啡酸和阿魏酸

采用高效液相色谱法同时测定了口服液中的咖啡酸和阿魏酸含量,用Shim-pack VP-ODS柱(150 mm×4.6 mm,0.3μm),流动相:乙腈-3%的冰醋酸水溶液(体积比为11∶89),流速:1.0 mL/min,检测波长:321 nm.咖啡酸和阿魏酸的浓度与峰面积呈良好的线性关系,其线性范围分别为0.126～63.0 μg/mL(r=0.999 7)和0.120～24.0 μg/mL(r=0.999 9),平均回收率(n=3)分别为100.7%和99.9%,相对标准偏差(RSD)分别为2.11%和2.12%,检出限分别为42 ng/mL和43 ng/mL,样品中咖啡酸和阿魏酸的平均含量分别为3.26μg/mL和2.36μg/mL.

Abstract：

An HPLC method was established for the simultaneous determination of ferulic acid and caffeic acid in oral liquid. The Shim-pack VP-ODS column (150 mm×4.6 mm, 0.3 μm) was used with a mobile were detected at a wavelength of 321 nm. The flow rate was 1.0 mL/min and the injection volume was 20 μL. The calibration curve was linear in the range of 0. 126-63.0 μg/mL (r=0. 999 7) for caffeic acid and 0. 120-24.0 μg/mL (r=0. 999 9) for ferulic acid. The average recovery (n=3) was 100.7% with RSD 2. 11% for caffeic acid and was 99.9% with RSD 2.12% for ferulic acid. The detection limit was 42 ng/mL for caffeic acid and 43 ng/mL for ferulic acid. The average content of the samples was 3. 26 μg/mL for caffeic acid and 2.36 μg/mL for ferulic acid.