The adsorption mechanism of O-isopropyl-S-[2-(hydroxyimino) propyl] dithiocarbonate ester(IPXPO) to chalcopyrite was investigated by using contact angle, in-situ atomic force microscopy(in-situ AFM), cyclic voltammetr...The adsorption mechanism of O-isopropyl-S-[2-(hydroxyimino) propyl] dithiocarbonate ester(IPXPO) to chalcopyrite was investigated by using contact angle, in-situ atomic force microscopy(in-situ AFM), cyclic voltammetry(CV) and X-ray photoelectron spectroscopy(XPS). The results of contact angle and in-situ AFM demonstrated that IPXPO adsorbed on chalcopyrite increases surface hydrophobicity and roughness. It was found by CV experiments that a layer passive film was formed. The results of XPS spectra further revealed that the thiol S atom, oxime N atom, and O atom in the IPXPO molecule might react with copper atoms to form Cu-S, Cu-N, and Cu-O bonds, respectively. An artificial mixed minerals flotation test indicated that under the condition of pH=6.79 and IPXPO initial concentration 5×10^(-5)mol/L, the flotation recovery of chalcopyrite reached about 90%, while for pyrite only 25%, suggesting that IPXPO is an excellent collector for flotation separation and enrichment of chalcopyrite.展开更多
Low molecular weight N-succinyl-chitosans with different degrees of substitution were synthesized by controlling reaction temperature, reaction time, and the molar ratio of the low molecular weight chitosan to succini...Low molecular weight N-succinyl-chitosans with different degrees of substitution were synthesized by controlling reaction temperature, reaction time, and the molar ratio of the low molecular weight chitosan to succinic anhydride. The structure of the low molecular weight N-succinyl-chitosan was characterized by infrared spectroscopy(IR), by which —COCH_ 2CH_ 2COOH was proved to be introduced to the —NH_ 2 of the low molecular weight chitosan. The moisture adsorption and moisture retention capacities of the low molecular weight chitosan derivatives with different degrees of substitution were investigated. The results indicate that the moisture adsorption and moisture retention capacities of the low molecular weight N-succinyl-chitosan increase with the increase of the degree of substitution. When the degree of substitution is greater than 38%, the derivatives have better moisture adsorption and moisture retention capacities than hyaluronic acid.展开更多
为了考察水产品中二甲苯麝香和酮麝香的残留量，建立了水产品中痕量二甲苯麝香和酮麝香测定的多重吸附同步净化（MASP）-气相色谱-质谱联用法（GC-MS）。以乙腈高速匀浆提取样品，应用 MASP 方法对样品同时进行提取、盐析和净化，并采用...为了考察水产品中二甲苯麝香和酮麝香的残留量，建立了水产品中痕量二甲苯麝香和酮麝香测定的多重吸附同步净化（MASP）-气相色谱-质谱联用法（GC-MS）。以乙腈高速匀浆提取样品，应用 MASP 方法对样品同时进行提取、盐析和净化，并采用 GC-MS 在选择离子监测（ SIM）模式下测定水产品中的痕量二甲苯麝香和酮麝香，以基质匹配标准溶液外标法定量。选用 DB-5 MS 石英毛细管柱（30 m×0.25 mm×0.25μm），采用电子轰击电离源，二甲苯麝香的选择监测离子为 m / z 282、297、265，酮麝香为 m / z 279、294、191。结果表明：在优化条件下，二甲苯麝香和酮麝香在1～100μg / kg 范围内线性良好，相关系数不低于0.999，检出限（S / N =3）为0.30μg / kg。明虾、花蛤和鳗鱼空白样品中1.0、2.0、10.0μg / kg 3个添加水平下二甲苯麝香和酮麝香的加标回收率为79％～104％，相对标准偏差（RSD）为1.6％～13.3％。本方法具有操作简便、快速、准确的特点，可用于水产品中痕量二甲苯麝香和酮麝香的日常检测。展开更多
基金Projects(22108114, 5180031184) supported by the National Natural Science Foundation of China。
文摘The adsorption mechanism of O-isopropyl-S-[2-(hydroxyimino) propyl] dithiocarbonate ester(IPXPO) to chalcopyrite was investigated by using contact angle, in-situ atomic force microscopy(in-situ AFM), cyclic voltammetry(CV) and X-ray photoelectron spectroscopy(XPS). The results of contact angle and in-situ AFM demonstrated that IPXPO adsorbed on chalcopyrite increases surface hydrophobicity and roughness. It was found by CV experiments that a layer passive film was formed. The results of XPS spectra further revealed that the thiol S atom, oxime N atom, and O atom in the IPXPO molecule might react with copper atoms to form Cu-S, Cu-N, and Cu-O bonds, respectively. An artificial mixed minerals flotation test indicated that under the condition of pH=6.79 and IPXPO initial concentration 5×10^(-5)mol/L, the flotation recovery of chalcopyrite reached about 90%, while for pyrite only 25%, suggesting that IPXPO is an excellent collector for flotation separation and enrichment of chalcopyrite.
文摘Low molecular weight N-succinyl-chitosans with different degrees of substitution were synthesized by controlling reaction temperature, reaction time, and the molar ratio of the low molecular weight chitosan to succinic anhydride. The structure of the low molecular weight N-succinyl-chitosan was characterized by infrared spectroscopy(IR), by which —COCH_ 2CH_ 2COOH was proved to be introduced to the —NH_ 2 of the low molecular weight chitosan. The moisture adsorption and moisture retention capacities of the low molecular weight chitosan derivatives with different degrees of substitution were investigated. The results indicate that the moisture adsorption and moisture retention capacities of the low molecular weight N-succinyl-chitosan increase with the increase of the degree of substitution. When the degree of substitution is greater than 38%, the derivatives have better moisture adsorption and moisture retention capacities than hyaluronic acid.
文摘为了考察水产品中二甲苯麝香和酮麝香的残留量，建立了水产品中痕量二甲苯麝香和酮麝香测定的多重吸附同步净化（MASP）-气相色谱-质谱联用法（GC-MS）。以乙腈高速匀浆提取样品，应用 MASP 方法对样品同时进行提取、盐析和净化，并采用 GC-MS 在选择离子监测（ SIM）模式下测定水产品中的痕量二甲苯麝香和酮麝香，以基质匹配标准溶液外标法定量。选用 DB-5 MS 石英毛细管柱（30 m×0.25 mm×0.25μm），采用电子轰击电离源，二甲苯麝香的选择监测离子为 m / z 282、297、265，酮麝香为 m / z 279、294、191。结果表明：在优化条件下，二甲苯麝香和酮麝香在1～100μg / kg 范围内线性良好，相关系数不低于0.999，检出限（S / N =3）为0.30μg / kg。明虾、花蛤和鳗鱼空白样品中1.0、2.0、10.0μg / kg 3个添加水平下二甲苯麝香和酮麝香的加标回收率为79％～104％，相对标准偏差（RSD）为1.6％～13.3％。本方法具有操作简便、快速、准确的特点，可用于水产品中痕量二甲苯麝香和酮麝香的日常检测。
