复合金属离子对薯莨提取液增重真丝的处理

在通过汽蒸法薯莨提取液增重真丝的基础上,选择4种Fe2+-Ti4+、Cr6+-Fe3+、Fe2+-Fe3+、Fe2+-Cu0'复合离子对增重真丝做后处理,讨论了不同质量浓度比例的金属离子对织物增蕈率、得色量的影响.结果表明:Cra+-Fe3+后处理对织物增重率的影响最大;Fe2+-Fe3+后处理随Fe2+质量浓度的升高,织物的增重率逐渐下降;而Fe2+-Ti4+和Fe2+-Cu2+后处理随Fe2+质量浓度升高增重率增大.4种复合离子比例不同,织物的颜色偏向离子质量浓度大的一方.金属离子后处理不同程度地提高了织物的色牢度、折皱回复性,降低了织物的透气性,织物的紫外屏蔽性能大大提高.经测试,真丝织物通过复合离子处理后,内部结构没有明显影响.     

胆碱-赖氨酸离子液体选择性降低卷烟烟气中的氰化氢和巴豆醛

为选择性降低卷烟主流烟气中氰化氢(HCN)和巴豆醛的释放量,采用滤嘴减害添加剂模拟测试装置对20种天然氨基酸进行了筛选,优选赖氨酸制备了气相二氧化硅固载的胆碱-赖氨酸离子液体([Ch][Lys]/SiO_2)颗粒材料(0.30~0.20 mm,60~80目),对材料进行了结构表征和减害性能模拟评价,并通过二元复合滤棒形式进行了卷烟应用效果考察和感官质量评价。减害性能测试结果显示:赖氨酸对降低HCN和巴豆醛有显著效果(P0.01);[Ch][Lys]/SiO_2的作用效果优于赖氨酸,可使对照卷烟烟气中HCN和巴豆醛的释放量分别降低83%和29%,降幅与添加量(0~0.3 mmol/支)线性正相关。卷烟应用效果表明:二元复合滤棒中[Ch][Lys]/SiO_2的添加量为0.08 mmol/支时,试验卷烟烟气中HCN和巴豆醛释放量较对照卷烟分别降低28%和10%;烟气常规成分及氨、NNK、B[a]P、苯酚等其他代表性有害成分的释放量变化较小;卷烟风格基本一致,感官质量无显著差异(P0.05)。     

功能性氨基酸离子液体的制备及卷烟应用评价

为开发可同时降低烟气中氰化氢(HCN)和巴豆醛释放量的卷烟减害功能材料,制备了20种四丁基铵-氨基酸离子液体(TBAILs),对其进行了结构表征及减害性能评价;并以涂布纸-醋纤二元复合滤棒形式开展了卷烟应用实验,考察了对HCN和巴豆醛的降低性能及其稳定性。结果表明:①红外光谱、核磁共振谱表征证明合成产物为TBAILs,热重分析显示TBAILs在150℃下具有较好的热稳定性。②卷烟减害性能模拟评价结果表明,制备的20种TBAILs对HCN释放量的降低率均高于80%,其中13种对巴豆醛释放量降低率60%。③将制备的四丁基铵-苏氨酸离子液体([N_(4444)][Thr])应用于卷烟,与对照样品相比,在10 mg/支添加量下主流烟气中HCN和巴豆醛分别降低50.8%和27.7%,卷烟感官质量变化较小。卷烟样品放置3月后离子液体减害性能保持稳定。     

原子吸收石墨炉法测定白酒中的氰化物

通过对白酒样品进行前处理后,利用氰化物能与铜离子、CTAB生成稳定的Cu2+-CN--CTAB三元络合物,再用正戊醇将络合物萃入有机相,用石墨炉原子吸收法测定络合物中铜的含量,间接求得氰的含量。同时对增敏剂加入量和介质酸度的影响,以及基体和共存离子的干扰情况等进行研究,结果表明,该法检出限为0.24μg/L,样品加标回收率为96.4%~103.1%。     

主流烟气中氨与部分羰基化合物的偏相关分析及应用

为提高离子色谱(IC)法测定卷烟主流烟气中氨的待测液的稳定性,分析了57种卷烟主流烟气中氨与部分挥发性羰基化合物(甲醛、乙醛、丙酮、丙烯醛、丙醛、巴豆醛和2-丁酮)的偏相关性;根据偏相关分析结果,以甲醛-HCl混合溶液(甲醛质量分数为15%,HCl物质的量浓度为100 mmol/L)作为萃取液对现行的检测方法(YC/T 377—2010)进行了改进,并考察了5种卷烟样品氨待测液的稳定性。结果表明:1主流烟气中的氨与甲醛呈极显著负相关,且二者在氨的待测溶液中会协同升高;2改进现有IC方法的萃取液后,5种卷烟样品的氨待测液经过24 h仍然比较稳定;3方法改进后,检出限为0.30μg/支,加标回收率为97.05%~102.40%,日间相对标准偏差(RSD)为1.28%。该方法较好地解决了待测液氨检测结果随时间不断升高的问题,适用于分析卷烟主流烟气中氨的释放量。     

共存离子对DNS法测定纤维素酶活性的影响

共存离子是否直接干扰纤维素酶活力或者通过干扰还原性糖D N S法测定间接干扰纤维素酶活力的测定尚存在争议。通过外加不同种类的共存离子,研究了不同共存离子对DNS法测定葡萄糖标准液和纤维素酶活力的影响,并对共存离子干扰D N S法测葡萄糖含量及纤维素酶活性的原因进行了实验探索。实验结果表明:M n2+、Cu2+、Fe3+等金属离子对D NS法测定葡萄糖含量、D N S测定纤维素酶活力均产生不同程度的干扰,且浓度越高,干扰越大。当金属离子浓度为10 m m ol/L时,Mn2+、Cu2+分别导致葡萄糖的测定值为标准样的203.7%、24.3%,其余几种金属离子对测定值干扰较小。当Mn2+、Fe3+、Cu2+浓度为10 mmol/L时,分别导致纤维素酶活性的测定值为实际值的207.9%、85.6%和83.1%。金属离子对DNS法测定纤维素酶活力的干扰机理,可能是由于金属离子自身的氧化还原性导致吸光度的变化以及金属离子对酶水解效率的影响等多种作用协同的结果。     

Fe~(2+)离子对磷化液的影响

钢丝磷化过程中 ,磷化液中的Fe2 +离子含量会对磷化反应产生不利影响 :Fe2 +离子含量过高 (其质量浓度≥ 3g L)时会引起磷化液的失效 ,导致无磷化膜生成。磷化液中Fe2 +含量过高的主要原因是外部因素 :酸洗后的钢丝表面被高压水冲洗不净所致。     

氧化石墨烯-壳聚糖复合物涂布纸降低卷烟烟气中苯酚和巴豆醛

为选择性降低卷烟主流烟气中苯酚和巴豆醛的释放量,采用溶液共混法制备了氧化石墨烯-壳聚糖复合物(GO-CS)悬浮液,并涂布于纤维素纸上,利用扫描电子显微镜(SEM)、傅里叶变换红外光谱(FTIR)和热重分析仪(TG)对其进行表征;利用模拟评价装置考察GO-CS涂布纸的减害性能,并通过成型纸醋(纸+醋纤)复合滤棒进行了卷烟应用评价。结果表明:1GO在CS中分散性良好,GO-CS结构均匀一致,可成功负载于纤维素纸表面;2GO-CS中GO质量分数为10%,纤维素纸GO-CS涂布量为(2.4±0.2)g/m~2时模拟减害效果较好,苯酚和巴豆醛释放量分别降低37.5%和31.5%;3与对照卷烟相比,试验卷烟主流烟气中苯酚和巴豆醛释放量分别降低32.7%和29.3%,卷烟危害性评价指数降低9.1%,烟气常规成分及其他有害成分的释放量变化不大,且卷烟风格及感官质量保持基本一致。     

Fe2+对太湖蓝藻厌氧发酵产甲烷过程中关键酶的影响

通过研究不同质量浓度Fe2+对太湖蓝藻厌氧消化过程中相关酶活性的影响,以进一步提高其厌氧产甲烷的能力。结果表明,当添加Fe2+3 mg/L时,反应瓶中甲烷积累产量最高,为986.7mL,比空白对照组提高了43倍。同时,当Fe2+质量浓度为0.5 mg/L时,脱氢酶活性达到118 U,比空白对照组提高了76%;当Fe2+质量浓度为0.5 mg/L时,BAA-蛋白水解酶活性为3126.9 U,比空白对照组提高了83.4%;当Fe2+质量浓度为1 mg/L时,β-葡萄糖苷酶活性达到47 493 U,比空白对照组提高了6.3倍;当Fe2+质量浓度为3 mg/L时,F420摩尔质量为0.2 mmol/g,比空白对照组提高了4.3倍。     

AMP脱氨酶的生化性质研究

主要从底物浓度、温度、pH和常见离子等方面对相对分子量56ku左右的腺苷酸脱氨酶的催化作用的影响因素进行研究。通过酶的催化实验,结果表明:原始底物质量浓度为2.78×10-2g/L、温度为37℃、pH为5.9时,AMP脱氨酶催化活性最好,IMP的转化速度最高为1.965×10-2mol/min。同时考察了Cu2+、Fe2+、Al3+、Mn2+、Na+、Mg2+、Zn2+等阳离子和SO42-、Cl-、NO3-、CO32-、H2PO4-、B4O72-、柠檬酸根、EDTA离子等阴离子对AMP脱氨酶催化能力的影响。结果表明:柠檬酸根离子和Mn2+对AMP脱氨酶有明显激活性影响,其他离子浓度超过0.01mol/L时对AMP脱氨酶一般有抑制性影响,AMP脱氨酶商品酶在常温干燥状态下稳定性很好,4℃存放的酶液半衰期为5.5d。     

Ironmaking with ammonia at low temperature

This paper describes the reduction of hematite with ammonia for ironmaking, in which the effect of temperature on the products was examined. The results showed that the reduction process began at 430 °C during heating, and with an increase in temperature, the reduction mechanism changed apparently from a direct reduction of ammonia (Fe(2)O(3) + 2NH(3) → 2Fe + N(2) + 3H(2)O) to an indirect reduction via the thermal decomposition of ammonia (2NH(3) → N(2) + 3H(2), Fe(2)O(3) + 3H(2) → 2Fe + 3H(2)O) at temperatures over 530 °C. The final product obtained at 600 and 700 °C was pure metallic iron, in contrast with that formed at 450 °C, that is, a mixture of metallic iron and iron nitride. The results suggest the possibility of using ammonia as a reducing agent for carbonless ironmaking, which is operated at a much lower temperature than 900 °C in conventional coal-based ironmaking.     

锌、铁饱和乳铁蛋白体外抗HBsAg分泌的研究

目的:探讨锌饱和乳铁蛋白(Zn2+-BLF)、铁饱和乳铁蛋白(Fe2+-BLF)体外抑制乙型肝炎表面抗原分泌作用,为锌、铁乳铁蛋白应用于临床治疗乙型肝炎病毒(HBV)感染提供理论和试验依据。方法:以天然HBV感染HepG2细胞为模型,通过应用ELISA法测定细胞上清中的HBsAg水平来检测Zn2+-BLF、Fe2+-BLF的抗HBsAg分泌效果,并用MTT法对Zn2+-BLF、Fe2+-BLF对HepG2细胞的毒性进行研究。结果:Zn2+-BLF、Fe2+-BLF对细胞的最大无毒剂量(TD0)分别为1.5g/L、3.0g/L;先用HBV对HepG2细胞进行感染,再分别加入Zn2+-BLF、Fe2+-BLF,各浓度组Zn2+-BLF均对HBsAg分泌有一定抑制作用,Zn2+-BLF浓度1.0g/L时对HBsAg的抑制率达60.49%;浓度为1.0g/L、0.5g/L的Fe2+-BLF能显著抑制HBsAg的分泌,但0.1g/L的Fe2+-BLF不能显著抑制HBsAg的分泌。结论:当HepG2细胞感染HBV后,Zn2+-BLF、Fe2+-BLF可以显著抑制HBsAg的分泌,Zn2+-BLF对HBsAg的抑制作用强于Fe2+-BLF,但其作用机理有待深入研究。     

味精废水中离交废水的预处理技术

采用铁碳法、吹脱法和化学沉淀法对味精废水中离交废水的预处理进行了中试和小试。结果表明 ,以铸铁屑为主的Fe C法 ,当HRT为 2h时 ,pH从 1.97升至 4 .88,可大大减少后续中和吹氨所需石灰量 ,但Fe C还原和加石灰调节 pH处理成本相差并不大 ,Fe C还原对去除COD、氨氮和提高可生化性无明显效果。pH中和至 9 5～ 10 ,鼓气量在 10 0m3/h左右 ,水温加至 55℃左右 ,经 8h ,可将原水NH+4 N从 12mg/L左右降至 4 g/L左右 ,脱除率6 5%以上。磷酸氨镁法去除废水中NH4 + N试验结果表明 ,在ω(Mg2 +)∶ω(PO4 3- )∶ω(NH4 + N) =1∶1∶1时 ,随废水 pH升高 ,NH4 + N去除率逐步增大 ,pH10时去除率达 54%     

两种抽吸模式下吸烟机型对卷烟主流烟气总粒相物及7种化学成分检测结果的影响

为研究不同抽吸模式下吸烟机型对卷烟主流烟气总粒相物(TPM)和7种化学成分释放量检测结果的影响,以典型的不同焦油量(1.0~13.3 mg/支)的9种烤烟型和11种混合型卷烟样品为研究对象,考察了ISO和加拿大深度抽吸(HCI)模式下直线型(L)和转盘型(R)吸烟机对卷烟主流烟气总粒相物(TPM)和一氧化碳(CO)、4-(N-甲基-N-亚硝氨基)-1-(3-吡啶基)-1-丁酮(NNK)、苯并[a]芘(B[a]P)、巴豆醛、苯酚、氰化氢(HCN)、氨(NH₃)释放量测试结果的影响。结果表明:①HCI抽吸模式下两种吸烟机型测试结果的一致性弱于ISO抽吸模式; TPM、巴豆醛和HCN在HCI抽吸模式下两种吸烟机型测试结果的差异明显。②两种抽吸模式下卷烟主流烟气NNK、B[a]P和苯酚重复检测结果标准偏差(SD,n=5)与检测水平均值(m)的相关性总体上较CO、巴豆醛、HCN和NH₃高,但HCI抽吸模式下检测结果SD与检测水平m的相关性弱于ISO抽吸模式。③在两种抽吸模式下,卷烟主流烟气相关指标不同吸烟机型测试结果总体精密度差异基本一致,即R型吸烟机对于20个不同烟气释放量水平样品重复测试结果的平均变异系数(CV)大多低于L型。      

The effect of modified starches on the adsorption of cigarette mainstream smoke composition

In this work modified starches such as porous starch (PS) and cross‐linked phosphorylated porous starch (PPS) were used as tobacco filter to investigate their adsorption efficiency on the tar, ammonia (NH₃), hydrocyanic acid (HCN), crotonaldehyde, and total particulate matter (TPM) in mainstream cigarette smoke. The pore properties and structural stability of the modified starches have been evaluated and the adsorption relationship between the modified starches and the main toxicants in tobacco smoke has also been established. Analytes of mainstream smoke from experimental cigarettes show reductions in yields of some measured constituents in mainstream cigarette smoke, such as tar, HCN, NH₃, crotonaldehyde, and TPM. The largest reductions are for NH₃ levels, up to 35.93% in one case, observed from the tobacco filter containing PPS. The largest reductions in mainstream yields of HCN (13.04%) and crotonaldehyde (31.06%) smoke toxicants were also observed. These results indicate that reducing exposure to some smoke toxicants is possible using the modified starches such as PS and PPS as tobacco filter.     

薯类作物中铁含量的测定

介绍了薯类作物中铁离子含量的测定方法。文中用干灰化法处理样品,把样品置于530℃马福炉中灰化,使铁游离出来,再用盐酸羟胺将其还原成Fe2+,用邻二氮菲分光光度法在510 nm波长处测定橙红色络和物Fe(Phen)32+的吸光度,由标准曲线及样品的吸光度可查得样品溶液的铁含量。经过测定和计算,薯类作物中铁含量大小顺序为马铃薯、芋头、魔芋、菱角、荸荠、山药、红薯。     

普洱茶-硒掺杂碳量子点和单质硒的同时制备及其在Fe3+检测中的应用

目的:为探讨普洱茶-纳米硒制备掺杂型碳量子点的可行性及其相关特性,实现水体系中Fe³⁺的快速检测。方法:以普洱茶水提取物稳定分散的普洱茶-硒原子为掺杂原子,采用水浴法,通过优化反应温度和时间,同时制备出普洱茶-硒掺杂碳量子点(Pu-erh tea nano-selenium doped carbon quantum dots,PT-Se-CQDs)和单质硒两种物质;采用紫外-可见吸收光谱和荧光光谱等技术表征PT-Se-CQDs的紫外-可见吸收特性和荧光强度,采用透射电子显微镜、X射线光电子能谱及X射线衍射等技术表征其形态形貌、元素组成及结构特性;并以PT-Se-CQDs为荧光探针构建荧光传感器,用于水体系中Fe³⁺检测。结果:当反应温度100℃、反应时间10 h时,可同时制备得量子产率为3.41%、平均直径约为3.1 nm的类球形PT-Se-CQDs和单质硒。Fe³⁺对PT-Se-CQDs具有强荧光静态猝灭效应,当Fe³⁺浓度为0～300μmol/L时,比率荧光强度(F/F₀)...     

Evaluation of various ammonia assays for testing of contaminated muscle food products

ABSTRACT:  The indophenol method, ammonia ion selective electrode (ISE), Reflectoquant® test strips, and salicylate methods were evaluated to determine those that can be used for in-plant rapid testing of meat contaminated by ammonia refrigerant leaks. Ground eye of round beef samples were spiked with 25, 50, 100, or 200 ppm ammonia as (N) and the amounts recovered were corrected for typical background levels. The recovery of ammonia from spiked meat filtrates by ISE ranged from 98.3% to 100%± 2%, and the recovery of ammonia from spiked meat samples by ISE-perchloric acid method ranged from 90% to 110%± 8%. The measurement of ammonia in spiked meat samples by the Reflectoquant test strips ranged from 77.4% to 96.9%, but the standard deviation was higher than 14%. The recovery using the salicylate methods was less than 63% when meat samples were spiked with 25 or 50 ppm ammonia. Both indophenol and ammonia ISE are precise, give excellent recovery, and can be used for testing ammonia contamination in meat. Ammonia background levels of various commercial meat products was determined using the ammonia ISE and ranged from 87 to 166 ppm.     

Plasma concentration of urea, ammonia, glutamine around calving, and the relation of hepatic triglyceride, to plasma ammonia removal and blood acid-base balance

Two experiments were conducted to test the following two hypotheses: 1) fatty liver could hamper hepatic conversion of ammonia to urea and increase circulating ammonia or Gln% [Gln% = Gln x 100/(Gln + Glu)] in cows around parturition; 2) decreased ureagenesis might cause alkalosis and in turn reduce blood Ca. In the first experiment, 14 Holstein cows were monitored from 27 d prepartum to 35 d postpartum. There was a rise in circulating ammonia and Gln% at calving, suggesting an increase in ammonia passing to and through the liver. Stepwise regression analysis revealed the following relationship for plasma samples at 22 h and liver triglyceride at 2 d postpartum: ammonia (microM) = 32.1+/-0.89 triglyceride (% DM), Gln% = 71.2 + 0.23 triglyceride (% DM) + 1.31 urea (mM). The positive correlation between liver triglyceride and plasma ammonia and Gln% suggests that hepatic triglyceride accumulation might inhibit ureagenesis, thereby increasing ammonia concentration at the perivenous hepatocytes where Gln synthesis occurs and increasing ammonia concentration in blood leaving the liver. In the second experiment, 28 rats were used to determine whether hepatic triglyceride accumulation, induced by choline deficiency, affects urinary ammonia N and blood pH homeostasis. There was a trend for a positive correlation between urinary ammonia N and liver triglyceride. No correlation between liver triglyceride and blood pH, bicarbonate, pCO2 or plasma Ca was found. In conclusion, hepatic triglyceride accumulation may inhibit ureagenesis and result in increased circulating ammonia, Gln% and urinary ammonia N in vivo. Hepatic triglyceride accumulation did not affect blood pH homeostasis.     

响应面法优化猪血复合微量元素补铁剂螯合工艺

采用响应面法优化猪血复合微量元素补铁剂的螯合工艺。在单因素试验的基础上,选择pH值、多肽溶液质量分数、多肽溶液与1.0 mol/L FeCl2溶液的体积比为影响因素,以Fe2＋螯合率为指标,进行3因素3水平的Box-Behnken试验设计,采用响应面法分析3 个因素对响应值的影响。结果表明：响应面法优化猪血复合微量元素补铁剂的最佳螯合工艺条件为pH值5.40、多肽溶液质量分数2.27%、多肽溶液与1.0 mol/L FeCl2溶液的体积比2.16∶1;在此条件下,猪血多肽Fe2＋螯合率的预测值为79.37%,实测值为79.41%。