A validated stability-indicating LC method for the separation of enantiomer and potential impurities of Linezolid using polar organic mode

Although a number of methods are available for evaluating Linezolid and its possible impurities, a common method for separation if its potential impurities, degradants and enantiomer in a single method with good efficiency remain unavailable. With the objective of developing an advanced method with shorter runtimes, a simple, precise, accurate stability-indicating LC method was developed for the determination of purity of Linezolid drug substance and drug products in bulk samples and pharmaceutical dosage forms in the presence of its impurities and degradation products. This method is capable of separating all the related substances of Linezolid along with the chiral impurity. This method can also be used for the estimation of assay of Linezolid in drug substance as well as in drug product. The method was developed using Chiralpak IA (250 mm 4.6 mm, 5 mm) column. A mixture of acetonitrile, ethanol, n-butyl amine and trifluoro acetic acid in 96:4:0.10:0.16 (v/v/v/v) ratio was used as a mobile phase. The eluted compounds were monitored at 254 nm. Linezolid was subjected to the stress conditions of oxidative, acid, base, hydrolytic, thermal and photolytic degradation. The degradation products were well resolved from main peak and its impurities, proving the stability-indicating power of the method. The developed method was validated as per International Conference on Harmonization (ICH) guidelines with respect to specificity, limit of detection, limit of quantification, precision, linearity, accuracy, robustness and system suitability.

Interest Sharing Mode of Fruit Industrialization from the Perspective of Enterprise

Firstly,connotation of fruit industrialization is introduced,pointing out that fruit leading enterprise is an important vector of the operation of fruit industrialization,as well as the economic entity for the market exploitation,production and processing,and service offering of fruit industry.Secondly,advantages and disadvantages of the three typical interest sharing modes during fruit industrialization are analyzed from the perspective of benefit sharing.In the organizational mode of "leading enterprise + fruit farmer" in contractual relationship,fruit enterprise plays a major role and is at a dominant position in the negotiation;while fruit farmer is at a relatively weak position,which has seriously frustrated the enthusiasm of fruit farmers.In the organizational mode of "specialized market + fruit farmer" in market transaction relationship,due to the restriction of certain factors,few agricultural enterprises participate in this mode;while fruit farmers are at a relatively weak position.Therefore,this mode can hardly promote the development of industrialization.In the organizational mode of "specialized agricultural association or cooperative + fruit farmer" in cooperative organization pattern,specialized association or cooperative protects the interests of fruit farmers,but neglects the interests of fruit enterprises.Finally,the vertical-horizontal integrated mode is put forward based on the development experience of the world and the actual situation of China,so as to provide guidance and reference for the fruit industrialization in China.

On the Operation and Organization Mode of the Enterprise＇s E-commerce

The E-business organization of enterprise comes into being due to the demand of era. With the development of the society, it has been developing from H type to U Mode, to the shape of matrix and then to the shape of the network. The evolution of these modes is derived from the necessity to serve customers and society better. This is the current E-business organization mode.

Distribution and occurrence of trace elements in the No.14 coal from the Huolinhe mine

Optical microscopy, and scanning electron microscopy in conjunction with energy dispersed X-ray spectrometry （SEM-EDX）, have been used to study the minerals and the concentrations of 12 trace elements in the No.14 coal from the Huolinhe mine, Inner Mongolia China. The distribution, affinity and removability of the trace elements were studied by float-sink experiments and petrological methods. A high mineral content, dominated by clay minerals, was found in the No.14 coal from the Huolinhe mine. The concentrations of As, Sb and Hg are relatively high compared to the average values for Chinese coals. As, Cr, Hg, Li, Mn, Pb are mainly associated with the minerals while Cd, Co, Ni, Sb, and Se are evenly distributed between the minerals and the organic matter. Be and Ba are mainly distributed in the minerals with a minor proportion in the organic matter. Most elements have a low organic affinity, although Sb, Se, Co, Cd, Ni are closely integrated with the organic matter. High theoretical removabilities are indicated for most trace elements. So it may be possible to lower the concentrations of trace elements during coal preparation.

Modes of Mesoscale Convective System Organization During Meiyu Season over the Yangtze River Basin

Mesoscale convective systems （MCSs） are classified and investigated through a statistical analysis of composite radar reflectivity data and station observations during June and July 2010-2012. The number of linear-mode MCSs is slightly larger than the number of nonlinear-mode MCSs. Eight types of linear-mode MCSs are identified： trailing stratiform MCSs （TS）, leading stratiform MCSs （LS）, training line/adjoining stratiform MCSs （TL/AS）, back-building/quasi-stationary MCSs （BB）, parallel stratiform MCSs （PS）, bro- ken line MCSs （BL）, embedded line MCSs （EL）, and long line MCSs （LL）. Six of these types have been identified in previous studies, but EL and LL MCSs are described for the first time by this study. TS, LS, PS, and BL MCSs are all moving systems, while TL/AS, BB, EL, and LL MCSs are quasi-stationary. The average duration of linear-mode MCSs is more than 7 h. TL/AS and TS MCSs typically have the longest durations. Linear-mode MCSs often develop close to the Yangtze River, especially over low-lying areas and river valleys. The diurnal cycle of MCS initiation over the Yangtze River valley contains multiple peaks. The vertical distribution of environmental wind is decomposed into storm-relative perpendicular and parallel wind components. The environmental wind field is a key factor in determining the organizational mode of a linear-mode MCS.

Numerical model to quantify biogenic volatile organic compound emissions:The Pearl River Delta region as a case study

This article compiles the actual knowledge of the biogenic volatile organic compound（BVOC） emissions estimated using model methods in the Pearl River Delta（PRD） region, one of the most developed regions in China. The developed history of BVOC emission models is presented briefly and three typical emission models are introduced and compared. The results from local studies related to BVOC emissions have been summarized. Based on this analysis, it is recommended that local researchers conduct BVOC emission studies systematically, from the assessment of model inputs, to compiling regional emission inventories to quantifying the uncertainties and evaluating the model results. Beyond that,more basic researches should be conducted in the future to close the gaps in knowledge on BVOC emission mechanisms, to develop the emission models and to refine the inventory results. This paper can provide a perspective on these aspects in the broad field of research associated with BVOC emissions in the PRD region.

Decontamination of alachlor herbicide wastewater by a continuous dosing mode ultrasound/Fe^(2+)/H_2O_2 process

We used a ultrasound/Fe2＋/H2O2 process in continuous dosing mode to degrade the alachlor. Experimental results indicated that lower pH levels enhanced the degradation and mineralization of alachlor. The maximum alachlor degradation （initial alachlor concentration of 50 mg/L） was as high as 100% at pH 3 with ultrasound of 100 Watts, 20 mg/L of Fe2＋, 2 mg/min of H2O2 and 20℃ within 60 min reaction combined with 46.8% total organic carbon removal. Higher reaction temperatures inhibited the degradation of alachlor. Adequate dosages of Fe2＋ and H2O2 in ultrasound/Fe2＋/H2O2 process not only enhance the degradation efficiency of alachlor but also save the operational cost than the sole ultrasound or Fenton process. A continuous dosing mode ultrasound/Fe2＋/H2O2 process was proven as an effective method to degrade the alachlor.