丙醇-水体系萃取浮选铜光度法间接测定硫离子

研究表明,Cu(Ⅱ)与 S2-形成CuS沉淀,在丙醇与水分相过程中,能被浮选于丙醇/水两相界面之间.Cu(Ⅱ)浮选率与S2-的量之间存在着良好的线性关系,据此建立了间接测定痕量S2-的新方法,线性范围2.2×10-8～3.2×10-6 g/mL,检出限为1.6×10-8 g/mL.常见多数阴、阳离子均不干扰测定,可用于污水与温泉水中痕量S2-的测定.     

硝酸钾-硫氰酸铵-水体系萃取浮选铜间接测定甲巯咪唑

建立了KNO3-NH4SCN-水体系萃取浮选铜间接测定甲巯咪唑的新方法.研究表明:在SCN-存在下,控制溶液pH 4.0～6.0,Cu(Ⅱ)可被甲巯咪唑分子中的巯基还原生成的Cu(I)与SCN-形成CuSCN白色乳状沉淀,加入KNO3可使该沉淀浮选至水相表面,通过测定溶液中剩余Cu(Ⅱ)的量,从而间接测定甲巯咪唑的含量.CuSCN的浮选率(E%)与甲巯咪唑的质量浓度呈良好的线性关系.当Cu(Ⅱ)加入量为50 μg时,测得线性范围为0.25～3.00 μg/mL(相关系数为0.9996).检出限为0.097 μg/mL.该法可用于片剂、血清、尿样中甲巯咪唑的测定.     

硝酸钾-硫氰酸铵-水体系萃取浮选硫氰酸亚铜间接测定头孢拉定

头孢拉定;硝酸钾;硫氰酸铵;铜;萃取浮选     

丙醇-硫酸铵-水体系沉淀浮选铜光度法测定头孢哌酮钠

本文建立了沉淀浮选铜光度法测定头孢哌酮钠的方法.研究表明头孢哌酮钠降解产物中的巯基使Cu(Ⅱ)还原生成的Cu(I)形成白色硫化物沉淀,该沉淀被浮选在丙醇/水两相界面之间.通过测定溶液中剩余Cu(Ⅱ)浓度的吸光度,可以测定头孢哌酮钠的含量.吸光度与头孢哌酮钠浓度之间存在良好线性关系.线性方程:A=4.683-0.0871...     

丙醇-溴化十六烷基三甲胺-硫酸铵-水体系萃取分离汞(Ⅱ)

研究了丙醇-溴化十六烷基三甲胺(CTMAB)-(NH4)2SO4-水体系萃取分离汞的行为及与常见离子分离条件.试验表明:调节pH1.0或3.0,能使Hg(Ⅱ)从Fe3+、Co2+、Ni2+、Zn2+、Mn2+、Cu2+、Al3+等离子混合液中分离出来.     

丙醇-溴化十六烷基三甲胺-硫酸按-水体系萃取分离汞(Ⅱ)

研究了丙醇-溴化十六烷基三甲胺(CTMAB)-(NH_4)_2SO_4-水体系萃取分离汞的行为及与常见离子分离条件.试验表明:调节pH1.0或3.0,能使Hg(Ⅱ)从Fe~(3+)、Co~(2+)、Ni~(2+)、Zn~(2+)、Mn~(2+)、Cu~(2+)、Al~(3+)等离子混合液中分离出来.     

沉淀浮选铜光度法测定头孢曲松钠

建立了沉淀浮选铜测定头孢曲松钠的新方法。研究表明:pH4.0,头孢曲松钠的降解产物中的巯基能将Cu(Ⅱ)还原成Cu(I),所生成的Cu(I)与降解产物中的巯基生成白色乳状硫化物沉淀。通过测定溶液中剩余Cu(II)的吸光度,可以间接测定头孢曲松钠的含量。线性方程:A=4.803+0.0886ρ(μg/mL),线性范围为0.60～35μg/mL,相关系数r=0.9996,表观摩尔吸光系数ε=5.1×104L·mol-1.cm-1。方法已用于测定头孢曲松钠注射剂中头孢曲松钠的含量。     

异丙醇-硫酸铵-水体系浮选硫氰酸亚铜法间接测定硫普罗宁

研究表明:控制溶液pH4.0,在SCN-存在下,Cu(Ⅱ)被硫普罗宁分子中的巯基(SH)还原生成的Cu(Ⅰ)与SCN-形成CuSCN白色乳状沉淀。该沉淀能被浮选在异丙醇/水两相界面之间。通过测定溶液中剩余Cu(Ⅱ)的量,从而间接测定硫普罗宁的量。硫普罗宁测量的线性范围0.30～12.0mg/L;检出限为0.20mg/L。本方法可直接用于片剂、血清、尿样中硫普罗宁含量的测定,结果满意。     

磷酸三丁酯萃取脱硫废液中硫氰酸根的初步研究

焦炉煤气含污染物H_2S 5g/m~3-8gm~3、HCN1g/m~3-2.5g/m~(3[1]),目前主要用催化氧化-氨水吸收法(NH_3-OMC)工艺处理.由此产生的脱硫脱氰废液中主要含有NH_4SCN、(NH_4)_2S_2O_3等无机盐,其中,SCN~-及S_2O_3~(2-)浓度均影响脱硫催化剂的效率,规定其总浓度不得超过250g/L.     

氯化钠-二乙基二硫代氨基甲酸钠-丙醇体系萃取分离铜

研究了氯化钠－二乙基二硫代氨基中甲酸钠－丙醇体系萃取铜的行为及丙醇水溶液分相条件的选择。实验表明,丙醇作为萃取溶剂,能萃取中性螯合物。在ＥＤＴＡ存在下,调节ｐＨ５－ｐＨ１０,该体系能使Ｃｕ６２＋从常见元素Ｆｅ＾３＋,Ｃｏ＾２＋,Ｎｉ＾２＋,Ａｌ＾３＋等离子的混合液中分离出来。     

Indirect determination of thiocyanate with ammonium sulfate and ethanol by extraction-flotation of copper

A new method for the indirect determination of thiocyanate with ammonium sulfate and ethanol by extraction-flotation of copper in the presence of ascorbic acid is described. A small amount of Cu(II) is reduced to Cu(I) by ascorbic acid, then Cu(I) is precipitated with SCN-. In the course of phase separation of ethanol from water, the precipitated CuSCN stays in the interface of ethanol and water. A good linear relationship is observed between the flotation yield of Cu(II) and the amount of SCN-. Using 1.0 ml of 1 x 10(-3) M ascorbic acid solution, 50 micrograms of Cu(II), 3.5 g of (NH4)2SO4 and 3.0 ml of ethanol with a total volume of 10 ml, the concentration of thiocyanate could then be determined by determining the flotation yield of Cu(II). The detection limit for thiocyanate is 5 x 10(-5) M. Every parameter was optimized and the reaction mechanism was studied. The method is simple and rapid and it was successfully applied to the determination of thiocyanate in urine and saliva of smokers and non-smokers and in venous blood of patients infused with sodium nitroprusside.     

Indirect determination of cefradine with n-propyl alcohol-ammonium sulfate-water system by extraction-flotation of cuprous thiocyanate

A new method was developed for the determination of cefradine by extraction-flotation of CuSCN.The experiment indicated that in the presence of 0.20 mol/L NaOH the degradation of cefradine took place in water bath at 100℃.The thiol group(-SH)of the degradation product could reduce Cu(Ⅱ)to Cu(Ⅰ)for the formation of the emulsion CuSCN in the presence of NH_4SCN at pH 4.0.By determining the residual amount of Cu(Ⅱ)in the solution and calculating the flotation yield of Cu(Ⅱ),the indirect determination of cefradine can be obtained.This method has been applied to determine cefradine in capsules,human serum and urine samples,respectively.     

Indirect determination of ampicillin sodium with sodium nitrate-ammonium thiocyanate-water system by extraction-flotation of cuprous thiocyanate

A novel method for indirect determination of ampicillin sodium by the extraction-flotation is proposed in this paper. It is indicated that the degradation of ampicillin sodium took place in the presence of 0.30 M sodium hydroxide in boiling water for 20 min. At pH 4.0, in the presence of ammonium thiocyanate, the thiol group of the degradation product of ampicillin sodium could reduce copper(II) to copper(I) due to the formation of the emulsion cuprous thiocyanate precipitation. By determining the residual amount of copper(II) in the solution and calculating the flotation yield of cuprous thiocyanate, the indirect determination of ampicillin sodium can be performed. When the concentration of cooper(II) was 5.0 μg/mL, a good linear relationship was obtained between the flotation yield of cuprous thiocyanate and the amount of ampicillin sodium in the range of 0.40～9.6 μg/mL. The linear equation is E = 4.1469 + 3.7949c with the correlation coefficient r = 0.9992, and the detection limit (3σ/K) of 0.37 μg/mL. Each parameter has been optimized and the reaction mechanism has been studied. The method has been successfully applied to the determination of ampicillin sodium in pharmaceutical, human plasma and urine samples. Analytical results obtained are satisfactory.     

在NaCl和SCN~-存在下浮选铜(Ⅱ)间接测定十六烷基三甲基溴化铵

研究了NaCl和NH4SCN浮选Cu(Ⅱ)间接测定十六烷基三甲基溴化铵的新方法。在水溶液中,Cu(Ⅱ)与SCN-和CTMAB缔合生成沉淀,在NaCl存在下,此沉淀被浮选。实验表明,Cu(Ⅱ)的浮选率与CTMAB的量在3.6~54.7 mg/L范围内呈良好的线性关系。CTMAB的检出限为1.8μg/mL。方法已用于合成水样和自来水中CTMAB的测定。     

Hydrazinium thiocyanate as a reagent for determination of copper

Hydrazinium thiocyanate, N(2)H(5)SCN, has been used for the determination of copper in copper salts. The reagent reduces the copper ions to the cuprous state and precipitates cuprous thiocyanate Cu(2)(SCN)(2), quantitatively.     

Spectrophotometric determination of thiocyanate via coprecipitation and thermal decomposition of copper(I) thiocyanate

A method for determination of thiocyanate (6–100 μg described. It is based on the coprecipitation of copper(I) thiocyanate with copper(I) iodide, followed by decomposition of copper(I) thiocyanate in air at 450°C. The decomposition products are CuS, CuO, SO₂, CO₂ and N₂. Released sulphur dioxide is absorbed in sodium tetrachloromercurate(II) solution, and determined spectrophotometrically with bleached p-rosaniline. The method is unaffected by the presence of halides, sulphide, sulphite and thiosulphate.     

Indirect determination of cefradine with n-propyl alcohol–ammonium sulfate–water system by extraction–flotation of cuprous thiocyanate

A new method was developed for the determination of cefradine by extraction-flotation of CuSCN. The experiment indicated that in the presence of 0.20 mol/L NaOH the degradation of cefradine took place in water bath at 100 ℃. The thiol group （-SH） of the degradation product could reduce Cu（Ⅱ） to Cu（Ⅰ） for the formation of the emulsion CuSCN in the presence of NH4SCN at pH 4.0. By determining the residual amount of Cu（Ⅱ） in the solution and calculating the flotation yield of Cu（Ⅱ）, the indirect determination of cefradine can be obtained. This method has been applied to determine cefradine in capsules, human serum and urine samples, respectively.