Degradation Dynamics and Residue Analysis of Flubendiamide in Cabbage and Soil by Liquid Chromatography-Tandem Mass Spectrometry with Dispersive Solid Phase Extraction

To formulate a scientific basis for a reasonable spray dose and safe interval period of 20% flubendiamide water dispersible granule (WDG) on controlling vegetable pests, degradation dynamics of flubendiamide in cabbage and soil was analyzed in this study. Dissipation and residue of flubendiamide in 20% flubendiamide WDG in cabbage and soil under field conditions were investigated by liquid chromatography-tandem mass spectrometry with dispersive solid phase extraction. Results showed that the degradation dynamic equations of flubendiamide in cabbage and soil were based on the first-order reaction dynamic equations. The half-lives of the degradation of flubendiamide were 3.51 d to 3.96 d and 3.43 d to 3.87 d in the cabbage of Yangzhou and Jingzhou, respectively, and 4.42 d to 5.13 d and 4.37 d to 4.99 d in the soil of Yangzhou and Jingzhou, respectively. The terminal residues of flubendiamide in the cabbage of Yangzhou and Jingzhou were 0.0247 mg·kg-1 to 0.0393 mg·kg-1 and 0.0225 mg·kg-1 to 0.0273 mg·kg-1, respectively, when 20% flubendiamide WDG was applied at a dose of0.050g·m-2. Flubendiamide is safe to be applied in cabbage fields at the recommended dose.

Influence of dispersants on coal-water slurry prepared from the solid residue of plasma pyrolysis of coal

This work presents the influence of dispersants on coal-water slurry(CWS),which was prepared from the solid residue of plasma pyrolysis of coal.The effects of dispersant type,solid concentration,dispersant content,and temperature on the rheological properties of CWS are examined.A suitable empirical model regarding the relation between viscosity and temperature is proposed.Through the sedimentation experiment of CWS,dispersants are found to significantly promote the stability of CWS.

Quantification of Solid Residues by Raman Spectroscopy

We suggest a mathematical route which has the capability to obtain quantitative information of solid residues on a substrate of aluminum, in which the evaporation of the deposited micro-drops has the form of coffee rings. In this job, the glycine aminoacid was used as probe molecule. We suppose that the number of moles present on the study sample is proportional to the Raman signal and to the experimental parameters of the used Raman system. Then, the mass and the number of molecules can be determined with these data. We showed that the mathematical expression is simple and elegant for its implementation. On the other hand, we have applied and demonstrated that the technique of principal component analysis (PCA) can be used to obtain quantitative information of the sample. Our results show quantitative analysis of glycine residues between 10-11 to 10-15 g.

Optimization of Solid State Fermentation Conditions Using a Mixture of Bean Curd Residue and Marc with Bacillus natto

[Objective] The aim was to optimize the appropriate solid state fermentation(SSF)conditions.[Method] The optimization of solid state fermentation using a mixture substrate of bean curd residue and the marc with Bacillus natto was developed.[Result] The best fermentation condition optimized by the test of single factor and the orthogonal design respectively was mixing ratio of bean curd residue to marc 2∶1,substrate pH value 6,fermentation temperature 39 ℃,inoculum volume 10% and fermentation time 48 h.Under this optimized fermentation condition,the content of crude fiber in the substrate decreased from 107.8 mg/g before SSF to 56.2 mg/g after SSF,and the degeneration rate of crude fiber was 47.87%.[Conclusion] The bean curd residue in its palatability was enormously improved by SSF with Bacillus natto strain,which could be expected to be widely used as raw material of health foodstuff.

Multiresidue Method for Determination of 67 Pesticides in Water Samples Using Solid-Phase Extraction with Centrifugation and Gas Chromatography-Mass Spectrometry

A new multi-residue method based on solid-phase extraction (SPE) with centrifugation was developed for determination and quantitation of 67 pesticides in water samples. Two SPE cartridges were tested: Chromabond C18 and Oasis HLB. Parameters that influence the extraction efficiency such as the eluent volume, the sample loading volume, the addition of organic solvent to water sample, sorbent drying and elute concentration were optimized. The innovation of this work was the examination of the use of a centrifugation technique in both the drying and elution steps. When combined with centrifugation, the volume of the elution solvent was reduced to 2 mL and the time for sorbent drying decreased also to 10 min under vacuum. Under the optimized conditions, this method showed good recoveries higher than 65% - 68% for the 67 analyzed pesticides using the C18 and HLB cartridges with relative standard deviations lower than 9.7% - 12.3%. Limits of quantification were between 2 and 20 ng.L–1. The simplicity of the described method, use of less of organic solvent, short procedure time, and good recoveries demonstrate the advantages of this environmentally friendly approach for routine analysis of numerous samples.

Direct Solid-State Fermentation of Soybean Processing Residues for the Production of Fungal Chitosan by Mucor rouxii

The feasibility of utilizing soybean-processing residues such as soybean meal and hulls as substrates for chitosan production by the fungus Mucor rouxii ATCC 24905 via solid-state fermentation (SSF) was investigated. The effects of the type of soybean-based substrate, length of cultivation period, substrate moisture content, substrate pH, incubation temperature and extraction conditions on chitosan yield were determined. The results showed that a maximum fungal chitosan yield of up to 3.44% by dry substrate weight (34.4 g/kg) could be achieved using a pure soybean meal substrate with an initial moisture content of 50% (w/w) and pH of 5 - 6 incubated for six days at 25&degC. A more severe heat treatment (autoclaving vs. refluxing) resulted in higher chitosan extraction yields regardless of the strength of extraction reagents. Fourier transform infrared (FTIR) analysis of the fungal chitosan revealed its degree of deacetylation (DDA) to be between 55% and 60%.

Fermentation characteristics of vinegar residue and some natural materials

Solid state fermentation is an attractive process to produce cellulase economically due to its lower financial investment and lower operating costs. Generally available natural materials in our study included vinegar residue, wheat bran, rice bran and wheat straw. Cellulase production was carried out by solid state fermentation using these materials as the substrate of Trichoderma koningii. The ingredients of natural materials, associated with the effects of water content, time and nitrogen sources on cellulase synthesis were studied. A comparatively high cellulase activity （〉4 IU·g^-1 SDM） was obtained in the fermentation batch. The optimum culture time of vinegar residue, wheat bran and wheat straw were 72 hours, but that office bran was 60 hours. Total water contents of wheat bran, rice bran and wheat straw should not exceed 50% and that of vinegar residue should not be more than 60%. It was also shown that nitrogen salts contributed much to fermentation. （NH4）3PO4 and urea achieved good results in promoting enzyme activity.

Preparation of colloidal Sb_2O_5 from arsenic-alkali residue

The stable colloidal antimony pentoxide was prepared by oxidation of the mixture of Sb2O3 and Sb2O5 obtained from arsenic-alkali residue by hydrometallurgical process, with hydrogen peroxide as oxidant and phosphoric acid as stabilizer. Effects of main factors were investigated. The theories on thermodynamics, kinetics and electrical double layer（EDL） were used to analyze the experimental phenomena and results. The results show that no aging time is the most beneficial to forming colloid, when molar ratio of phosphoric acid to antimony is in the range from （0.8） to 1.0 and 1.0 to 1.3, the particle sizes of sol with the concentration of 10% and 15% antimony pentoxide by mass are both smaller. With increasing concentration of the mixture of antimony oxide from 10% to 20%, the reaction time decreases from 90 to about 30min, but the optimized range of molar ratio of H3PO4 to antimony increases. The reaction temperature is not the main factor on particle size with the existence of H3PO4 in the temperature range from 60 to 90℃.

Direct Determination of Polychlorinated-Biphenyls in Automotive Shredder Residues by Gas Chromatography-Mass Spectrometry

An easy and rapid method is proposed for the determination of PCBs in automotive shredder residues, using gas chromatography combined with low resolution mass spectrometry (GC-MS). It is based on direct n-hexane solid-liquid extraction, subtracting background of the lineal aliphatic hydrocarbon interferences and integration of chromatographic peaks containing selected ion PCBs masses (256, 292 and 326 m/z), which are common in all PCBs formulations. Recoveries were in the 80% - 120% range;PCBs were detected and quantified in shredder samples from an automotive shredder industry, thus indicating the validity of the method.

火电厂燃煤产物中关键微量元素富集特征研究

煤系共伴生战略性关键元素可在燃煤产物中富集,研究燃煤产物中关键元素的富集特点可为元素的预富集和提取利用提供依据。以我国东西部不同火电厂燃煤产物为例,采用波长色散荧光光谱仪(AxiosmAX)、电感耦合等离子体质谱仪(iCAP-Qc)测试了燃煤产物中常量元素和关键微量元素的含量,分析了燃煤产物中关键微量元素分布富集的一般性规律。结果表明:①粉煤灰中主要常量元素为Si、Al、Fe,三者氧化物占比达87.79%;微量元素中稀土元素、锂、镓、铀、锗的含量分别为456.95μg/g、163.58μg/g、49.07μg/g、8.67μg/g、4.59μg/g,除铀、锗外均高于世界煤灰平均值。②常量元素中P趋向富集于细灰中,Fe、Ca更易富集于粗灰中;稀土元素分布模式保持一致,且在细灰中的含量高于粗灰,锂、镓、铀、锗均在细粒燃煤产物中更为富集,分异系数分别为1.17、2.45、1.53、2.14。③数理统计分析表明,煤中稀土元素与无机矿物相关,且富集于燃煤产物的非磁性组分中;锂主要与黏土矿物有关,燃烧后主要以LiAlO2的形式存在;镓、铀赋存形式不单一,与黏土矿物有一定的关系;锗与无机相相关性弱,表明其主要与有机质结合。

分散固相萃取净化-超高效液相色谱-串联质谱法测定蜂蜜中双甲脒、杀虫脒及其代谢物

该研究建立了分散固相萃取-超高效液相色谱-串联质谱(dispersive solid phase extraction-ultra-performance liquid chromatography,UPLC-MS-MS)检测蜂蜜中双甲脒、杀虫脒及其代谢物残留的分析方法。蜂蜜样品2 g加入10 mL水溶液充分混匀,经1%(体积分数)氨化乙腈超声辅助提取后离心,利用N-丙基乙二胺、C18、氨基键合硅胶混合材料进行分散固相萃取净化,采用ACQUITY UPLC BEH C18(2.1 mm×50 mm,1.7μm)色谱柱分离,以甲醇和0.1%(体积分数)甲酸水溶液为流动相进行梯度洗脱,多反应监测模式正离子扫描分析。6种农药及其代谢物平均回收率为84.1%~113.8%,相对标准偏差为0.9%~6.0%,检出限为0.2~0.8μg/kg,定量限为0.7~2.5μg/kg。实验结果表明该方法快速简便、灵敏度高,适用于蜂蜜中双甲脒、杀虫脒及其代谢物残留同时分析。

固相萃取-超高效液相色谱-三重四极杆/线性离子阱质谱法检测水中大环内酯类抗生素

采用固相萃取-超高效液相色谱-三重四极杆线性离子阱质谱技术(SPE-UPLC-QTRAP MS)建立了环境水样中阿奇霉素、林可霉素、克林霉素、红霉素及替米考星5种大环内酯类抗生素的检测方法。调节水样pH为10后经HLB固相萃取柱净化、富集,然后用Kinetex F5色谱柱进行分离,用0.1%甲酸水溶液和0.1%甲酸乙腈溶液进行洗脱,采用电喷雾正离子源(ESI+),多反应监测(MRM)-信息依赖采集(IDA)-增强子离子(EPI)扫描模式对样品进行检测,用多反应监测(MRM)进行定量,增强子离子(EPI)谱图库辅助定性。结果表明:5种大环内酯类抗生素线性关系良好,相关系数均大于0.9992;检出限为0.01~0.30μg·L^(-1),定量限为0.10~0.50μg·L^(-1);3种不同浓度的水样加标回收率为71.60%~111.05%,相对标准偏差均在10%以内,EPI谱库比对纯度值均大于90%。该方法将传统的MRM扫描模式结合EPI谱图库检索,实现了同时定性和定量分析,对未知物准确定性定量检测提供了重要参考。

单一菌与复合菌发酵甘草渣产有机酸能力比较

为研究单一菌与复合益生菌对甘草渣发酵饲料品质的影响,试验以甘草渣为基础原料,与麸皮、豆粕、糖蜜复配,在此基础上以单菌(植物乳杆菌、酿酒酵母)和复合菌(植物乳杆菌、酿酒酵母、枯草芽孢杆菌)为发酵剂,借助食品检测中的碱滴定法,测定发酵饲料中的总酸含量,通过比较发酵饲料总酸含量及pH结合感官评价,衡量发酵饲料的品质。结果表明:(1)单菌在不同碳氮比条件下发酵,碳氮比为30时生成有机酸含量较碳氮比为25提高了2.8倍。(2)单菌发酵第7天时有机酸含量达到最高值,且pH在发酵第7天时达到最低值。(3)复合益生菌发酵组(E组、F组)与单菌酿酒酵母组(B组)比较甘草渣发酵饲料中有机酸生成量分别提高了52%、52.48%。由此可见,复合益生菌(植物乳杆菌、酿酒酵母、枯草芽孢杆菌)有利于促进甘草渣饲料发酵,无论是气味还是有机酸生成量均比单一菌株甘草渣发酵更优,甘草渣有成为发酵饲料的潜在价值。

基于亚临界技术的铬革屑水解工艺研究

通过单因素实验和正交试验优化,亚临界水解铬革屑最优工艺为:温度150℃、液比25、反应时间75 min、CaO用量6%。铬革屑水解率为(83.98±0.16)%。水解过程无废液产生,水解产物主要为多肽、短肽和少量氨基酸。水解产物的铬含量为(34.81±2.29)mg/kg,符合农业部有机肥铬含量标准,具有作为有机肥的应用前景。铬革屑水解产生的铬绝大部分沉积在铬渣中。铬渣浸出液的铬和六价铬含量分别为14.285 mg/L和1.544 mg/L,低于国家标准《危险废物鉴别标准浸出毒性鉴别》的限值,实现了铬革屑无害化处理。

花岗岩废料与玻璃废渣制备发泡陶瓷的研究

本文以花岗岩废料和玻璃废渣为原料、SiC为发泡剂,采用粉末烧结法制备了高孔隙率、低吸水率的全固废发泡陶瓷,探究了花岗岩废料和玻璃废渣配合比、烧结温度、发泡剂掺量对发泡陶瓷孔结构及性能的影响。结果表明:花岗岩废料形成了发泡陶瓷的骨架结构,玻璃废渣具有助熔作用;当玻璃废渣掺量为20%(质量分数)时,烧结温度降低了40℃。在1110~1150℃下制备的发泡陶瓷抗压强度为2.23~0.41 MPa,体积密度为468.41~326.31 kg/m^(3),孔隙率为79.15%~86.81%,吸水率为0.96%~1.00%,平均孔径为0.49~1.43 mm,实现了对发泡陶瓷孔径的有效调控,满足了不同应用场景对发泡陶瓷不同孔径的需求。本研究为花岗岩废料和玻璃废渣的规模化利用及不同孔径发泡陶瓷的制备提供了技术支持。

固相萃取-高效液相色谱法同时测定水产品中15种磺胺类药物残留

建立固相萃取-高效液相色谱法(solid phase extraction-high performance liquid chromatography,SPE-HPLC)同时检测水产品中15种磺胺类药物(sulfonamides,SAs)残留。样品用乙酸乙酯提取,正己烷脱脂,PCX(polymer cation exchange)固相萃取柱净化,采用高效液相色谱法检测,色谱条件为:Waters C18(4.6 mm×250 mm,5.0μm)色谱柱分离,以甲醇和含体积分数1.1%乙酸的PBS缓冲液(0.01 mol/L)为流动相进行梯度洗脱,检测波长为270 nm。15种SAs在65 min内达到完全分离,在0.5~10.0μg/m L时线性关系良好,相关系数均大于0.9900;方法检出限为10~20μg/kg,定量限为20~60μg/kg;对空白鱼肉样品进行了3个质量分数水平(500、1000、2000μg/kg)的加标实验,测定其空白加标回收率为73.1%~109.6%,相对标准偏差(relative standard deviations,RSDs)在1.0%~6.7%。实验建立的检测方法重现性和稳定性好、检出限低。对江西10个不同品种的水产品中磺胺类药物残留进行了采样检测,结果均未检出,表明江西水产品中磺胺类药物残留情况并不严重。

通过式固相萃取结合高效液相色谱-四极杆飞行时间质谱测定鸡蛋中62种兽药残留

建立了固相萃取结合高效液相色谱-四极杆飞行时间质谱(HPLC-QTOF)同时测定鸡蛋中62种兽药残留的方法。鸡蛋均质后经90%甲酸乙腈水溶液提取后,PRiME HLB固相萃取小柱净化,氮吹后复溶,用(HPLC-QTOF)进行检测。62种兽药在0.5~500 ng/mL浓度范围内线性关系良好(r^(2)≥0.99),回收率在71.2%~113%之间,日内变异系数范围为1.3%~14.3%,日间变异系数范围为4.2%~18.3%,检测限为1.0~2.0μg/kg,定量限为2.0~5.0μg/kg。本方法简便快捷、准确可靠,适用于鸡蛋中62种兽药的同时测定。

基于石墨烯泡沫的电增强固相微萃取-高效液相色谱法测定鱼肉中3种磺胺类的残留

为提高鱼肉中磺胺类抗生素(sulfonamides,SAs)残留的富集效果,建立了基于氮掺杂三维石墨烯泡沫功能化整体柱(monolith@nitrogen-doped three-dimensional graphene foam,M@NGF)的电增强固相微萃取(electroenhanced solid phase microextraction,EE-SPME)方法,结合高效液相色谱技术,快速、灵敏地测定鱼肉中SAs残留。本研究采用原位聚合法,以离子液体为功能单体,NGF为导电增强剂,在不锈钢丝表面制备多孔M@NGF,建立EE-SPME方法,从鱼肉中萃取磺胺噻唑(sulfathiazole,ST)、磺胺二甲基嘧啶(sulfamethazine,SM_(2))和磺胺二甲氧嘧啶(sulfadimethoxypyrimidine,SMM)。对吸附时间、搅拌速度、吸附电压、离子强度、样品溶液p H值、解吸时间、解吸电压和解吸液组成进行了优化。结果表明,基于M@NGF的EE-SPME法对ST、SM_(2)和SMM的富集倍数分别为74、58和64,吸附平衡时间缩短至35 min。在5~5000μg/kg线性范围内,本方法对ST、SM_(2)和SMM的检出限分别为1.78、3.16μg/kg和1.84μg/kg,定量限均为5μg/kg,线性回归分析的决定系数(R^(2))均大于0.9990,加标回收率为79.2%~110.1%,相对标准偏差范围为1.4%~9.8%(n=5)。本方法解决了鱼肉中SAs残留萃取效率低、基质干扰严重的问题,实现了鱼肉中SAs残留的快速、灵敏检测。

Metagenomic insights into microorganisms and antibiotic resistance genes of waste antibiotic fermentation residues along production,storage and treatment processes

Antibiotic fermentation residue(AFR)is nutrient-rich solid waste generated from fermentative antibiotic production process.It is demonstrated that AFR contains high-concentration of remaining antibiotics,and thus may promote antibiotic resistance development in receiving environment or feeding farmed animals.However,the dominate microorganisms and antibiotic resistance genes(ARGs)in AFRs have not been adequately explored,hampering understanding on the potential antibiotic resistance risk development caused by AFRs.Herein,seven kinds of representative AFRs along their production,storage,and treatment processes were collected,and multiple methods including amplicon sequencing,metagenomic sequencing,and bioinformatic approaches were adopted to explore the biological characteristics of AFRs.As expected,antibiotic fermentation producer was found as the predominant species in raw AFRs,which were collected at the outlet of fermentation tanks.However,except for producer species,more environment-derived species persisted in stored AFRs,which were temporarily stored at a semi-open space.Lactobacillus genus,classified as Firmicutes phylum and Bacilli class,became predominant bacterial taxa in stored AFRs,which might attribute to its tolerance to high concentration of antibiotics.Results from metagenomic sequencing together with assembly and binning approaches showed that these newly-colonizing species(e.g.,Lactobacillus genus)tended to carry ARGs conferring resistance to the remaining antibiotic.However,after thermal treatment,remaining antibiotic could be efficiently removed from AFRs,and microorganisms together with DNA could be strongly destroyed.In sum,the main risk from the AFRs was the remaining antibiotic,while environment-derived bacteria which tolerate extreme environment,survived in ARFs with high content antibiotics,and may carry ARGs.Thus,hydrothermal or other harmless treatment technologies are recommended to remove antibiotic content and inactivate bacteria before recycling of AFRs in pharmaceutical industry.