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1.
The adsorption of dibenzothiophene (DBT) in hexadecane onto NaY zeolite has been studied by performing equilibrium and kinetic
adsorption experiments. The influence of several variables such as contact time, initial concentration of DBT and temperature
on the adsorption has been investigated. The results show that the isothermal equilibrium can be represented by the Langmuir
equation. The maximum adsorption capacity at different temperatures and the corresponding Langmuir constant (K
L
) have been deduced. The thermodynamic parameters (ΔG
0,ΔH
0,ΔS
0) for the adsorption of DBT have also been calculated from the temperature dependence of K
L
using the van’t Hoff equation. The value of ΔH
0,ΔS
0 are found to be −30.3 kJ mol−1 and −33.2 J mol−1 K−1 respectively. The adsorption is spontaneous and exothermic. The kinetics for the adsorption process can be described by either
the Langmuir model or a pseudo-second-order model. It is found that the adsorption capacity and the initial rate of adsorption
are dependent on contact time, temperature and the initial DBT concentration. The low apparent activation energy (12.4 kJ mol−1) indicates that adsorption has a low potential barrier suggesting a mass transfer controlled process. In addition, the competitive
adsorption between DBT, naphthalene and quinoline on NaY was also investigated. 相似文献
2.
Adsorption behavior of rice husk for the decontamination of chromium from industrial effluents 总被引:2,自引:0,他引:2
N. Khalid A. Rahman S. Ahmad A. Toheed J. Ahmed 《Journal of Radioanalytical and Nuclear Chemistry》1999,240(3):775-781
Rice husk, an agricultural waste product, was studied as a potential decontaminant for chromium in the effluents of leather
tanning industries. Physico-chemical parameters such as selection of appropriate electrolyte, shaking time, concentration
of adsorbent and adsorbate were studied to optimize the best conditions in which this material can be utilized on commercial
scale for the decontamination of effluents. The radiotracer technique was used to determine the distribution of chromium.
In certain cases atomic absorption spectrophotometry was also employed. Maximum adsorption was observed at 0.01 mol·dm−3 acid solutions (HNO3, HCl, H2SO4 and HClO4) using 3.0 g of adsorbent for 2.73·10−3 mol·dm−3 chromium concentration in five minutes equilibration time. Studies show that the adsorption decreases with the increase in
the concentrations of all the acids. The adsorption data follows the Freundlich isotherm over the range of 2.73·10−3 to 2.73·10−2 mol·dm−3 chromium concentration. The characteristic Freundlich constants, i.e., 1/n=0.86±0.06 andA=2.35±0.06 mmol·g−1 have been computed for the sorption system. Thermodynamic parameters, i.e., ΔG
0, ΔS
0 and ΔH
0 have also been calculated for the system. Application of the method to a test case of a medium size industry showed that
21 kg of rice husk was sufficient to maintain the NEQS limits of chromium for industrial effluents. 相似文献
3.
M. Mufazzal Saeed Abdul Ghaffar 《Journal of Radioanalytical and Nuclear Chemistry》1998,232(1-2):171-177
The nature of adsorption behavior of Au(III) on polyurethane (PUR) foam was studied in 0.2M HCl aqueous solution. The effect
of shaking time and amount of adsorbent were optimized for 3.16·10−5M solution of Au(III) in 0.2M HCl. The classical Freundlich and Langmuir adsorption isotherms have been employed successfully.
The Freundlich parameters 1/n and adsorption capacityK are 0.488±0.016 and (1.40±0.22)·10−2 mol·g−1, respectively. The Langmuir constants of saturation capacityM and binding energyb are (1.66±0.08)·10−4mol·g−1 and 40294±2947 l·g−1, respectively, indicating the monolayer chemical sorption. The mean free energy (E) of adsorption of Au(III) on PUR foam has been evaluated using D-R isotherm and found to be 11.5±0.16 kJ·mol−1 reflecting the ion exchange type of chemical adsorption. The effect of temperature on the adsorption has also been studied.
the isosteric heat of adsorption was found to be 44.03±1.66 kJ·mol−1. The thermodynamic parameters of ΔG, ΔH, ΔS and equilibrium constantK
c
have been calculated. The negative values of ΔG, ΔH and ΔS support that the adsorption of Au(III) on PUR foam is spontaneous, exothermic and of ion exchange chemisorption. The nature
of the Au(III) species sorbed on PUR foam have been discussed. 相似文献
4.
Adsorption of vanadium(V) from aqueous solution onto ZnCl2 activated carbon developed from coconut coir pith was investigated to assess the possible use of this adsorbent. The influence
of various parameters such as agitation time, vanadium concentration, adsorbent dose, pH and temperature has been studied.
First, second order, Elovich and Bangham’s models were used to study the adsorption kinetics. The adsorption system follows
second order and Bangham’s kinetic models. Langmuir, Freundlich, Dubinin-Radushkevich and Temkin isotherms have been employed
to analyze the adsorption equilibrium data. Equilibrium adsorption data followed all the four isotherms—Langmuir, Freundlich,
D-R and Temkin. The Langmuir adsorption capacity (Q
0) was found to be 24.9 mg g− 1 of the adsorbent. The per cent adsorption was maximum in the pH range 4.0–9.0. The pH effect and desorption studies showed
that ion exchange mechanism might be involved in the adsorption process. Thermodynamic parameters such as ΔG
0, ΔH
0 and ΔS
0 for the adsorption were evaluated. Effect of competitive anions in the aqueous solution such as PO4
3 −, SO4
2−, ClO4
−, MoO4
2−, SeO3
2−, NO3
− and Cl− was examined. SEM and FTIR were used to study the surface of vanadium(V) loaded ZnCl2 activated carbon. Removal of vanadium(V) from synthetic ground water was also tested. Results show that ZnCl2 activated coir pith carbon is effective for the removal of vanadium(V) from water. 相似文献
5.
Mercury-mercury (II) sulphide electrode has been prepared and its electrochemical and thermodynamic behaviour has been studied
in different media. The electrode is found to show Nernstian response to pS (− log [S2−]) over the range 5.19–10.38. In the pH range 7.96–11.98, at constant [S2−]v, its response is also Nernstian. The values of thermodynamic functions, viz., ΔG0. ΔH0, and ΔS0 for the electrode reaction: Hg(3)+S2−
aμ
⇌HgS(s)+2e, have been determined. Further, the standard free energy of formation (ΔG
f
0
) and solubility product constant (K
vp
) of HgS in aqueous medium at 25±0.1°C have also been determined. 相似文献
6.
Modified Sorrel’s cement was prepared by the addition of ferric chloride. The modified cement (MF5) was analyzed and characterized
by different methods. Adsorption of Gd(III) and U(VI) ions in carbonate solution has been studied separately as a function
of pH, contact time, adsorbent weight, carbonate concentration, concentration of Gd(III) and U(VI) and temperature. From equilibrium
data obtained, the values of Δ H, Δ S and Δ G were found to equal −30.9 kJ ⋅ mol−1, −85.4 J ⋅ mol−1 ⋅,K−1, and −5.4 KJ ⋅ mol−1, respectively, for Gd(III) and 18.9 kJ ⋅ mol−1, 67.8 J ⋅ mol−1 K−1 and −1.3 KJ ⋅ mol−1, respectively, for U(VI). The equilibrium data obtained have been found to fit both Langmuir and Freundlich adsorption isotherms.
The batch kinetic of Gd(III) and U(VI) on modified Sorrel’s cement (MF5) with the thermodynamic parameters from carbonate
solution were studied to explain the mechanistic aspects of the adsorption process. Several kinetic models were used to test
the experimental rate data and to examine the controlling mechanism of the adsorption process. Various parameters such as
effective diffusion coefficient and activation energy of activation were evaluated. The adsorption of Gd(III) and U(VI) on
the MF5 adsorbent follows first-order reversible kinetics. The forward and backward constants for adsorption, k
1and k
2 have been calculated at different temperatures between 10 and 60∘C. Form kinetic study, the values of Δ H
* and Δ S
* were calculated for Gd(III) and U(VI) at 25∘C. It is found that Δ H
* equals −14.8 kJmol−1 and 7.2 kJmol−1 for Gd(III) and U(VI), respectively, while Δ S
* were found equal −95.7 Jmol−1K−1 and −70.5 Jmol−1K−1 for Gd(III) and U(VI), respectively. The study showed that the pore diffusion is the rate limiting for Gd(III) and (VI). 相似文献
7.
Carboxymethyl cellulose Sn(IV) phosphate composite nano-rod like cation exchanger with diameter in the range of 20–40 nm,
length in the range of 100–150 μm and particle size in the range of 21–38 nm have been successfully prepared by surfactant
assisted sol–gel method. Scanning electron microscopy, transmission electron microscopy, X-ray powder diffraction, fourier
transform infra red spectroscopy and thermogravimetric analysis-differential thermal analysis studies were carried out to
study the structure and morphology of this composite nano-rod like cation exchanger. Freundlich adsorption isotherm is well
fitted for the adsorption of pyridine on the surface of this composite nano-rod like cation exchanger. The thermodynamic parameters
such as Freundlich constant, thermodynamic equilibrium constant (K
0), standard free energy changes (ΔG
0), standard enthalpy changes (ΔH
0) and standard entropy changes (ΔS
0) have been evaluated. These parameters indicated that the adsorption of pyridine on the surface of composite nano-rod like
cation exchanger was feasible, spontaneous and exothermic in nature which suggests for the potential application of pyridine
removal from water. 相似文献
8.
R. Donat K. Esen H. Cetisli S. Aytas 《Journal of Radioanalytical and Nuclear Chemistry》2009,279(1):253-261
Ulva sp. and sepiolite were used to prepare composite adsorbent. The adsorption of uranium(VI) from aqueous solutions onto Ulva sp.-sepiolite has been studied by using a batch adsorber. The parameters that affect the uranium(VI) adsorption, such as solution
pH, initial uranium(VI) concentration, and temperature, have been investigated and the optimum conditions determined. The
adsorption patterns of uranium on the composite adsorbent followed the Freundlich and Dubinin-Radushkevich (D-R) isotherms.
The Freundlich, Langmuir, and Dubinin-Radushkevich (D-R) models have been applied and the data correlate well with Freundlich
model. The sorption is physical in nature (sorption energy, E = 4.01 kJ/mol). The thermodynamic parameters such as variation of enthalpy ΔH, variation of entropy ΔS and variation of Gibbs free energy ΔG were calculated from the slope and intercept of lnK
d
vs. 1/T plots. Thermodynamic parameters (ΔH
ads
= −22.17 kJ/mol, ΔS
ads
= −17.47 J/mol·K, ΔG
o
ads
(298.15 K) = −16.96 kJ/mol) show the exothermic heat of adsorption and the feasibility of the process. The results suggested
that the Ulva sp-sepiolite composite adsorbent is suitable as a sorbent material for recovery and biosorption/adsorption of uranium ions from
aqueous solutions. 相似文献
9.
N. Kumaraguru K. Santhakumar S. Kalyanasundharam 《Journal of solution chemistry》2011,40(10):1673-1686
The critical micelle concentration (CMC) of surfactant–Cr(III)–dodecylamine complexes of the type cis-α-[Cr(trien)(C12H25NH2)X]2+ (where trien = triethylenetetramine; X = F−, Cl−, Br−) has been studied in n-alcohol and in formamide at different temperatures, by electrical conductivity measurements. From the CMC values as a function
of temperature, various thermodynamic properties have been evaluated: standard Gibbs energy changes (Δmic
G
0), standard enthalpy changes (Δmic
H
0) and standard entropy changes (Δmic
S
0) for micellization. Critical micelle concentrations have also been measured as a function of the percentage composition of
alcohol added. The solvent composition dependences of these thermodynamic parameters were determined. It is suggested that
alcohol addition leads to an increase in formamide penetration into the micellar interface that depends on the alcohol’s chain
length. The results are discussed in terms of an increased hydrophobic effect, dielectric constant of the medium, the chain
length of the alcohols, and the surfactant in the solvent mixture. 相似文献
10.
L. M. Cotoruelo M. D. Marqués A. Leiva J. Rodríguez-Mirasol T. Cordero 《Adsorption》2011,17(3):539-550
The adsorption processes of three aromatic chemicals onto activated carbons (ACs) from aqueous solutions have been studied.
Eucalyptus kraft lignin obtained from cellulose industry as a residual biomass has been used to prepare activated carbons
by physical activation with CO2. The influences of the activation time on the surface areas and pore volumes of the ACs were analyzed. The physicochemical
properties and the surface chemical structure of the adsorbents have been studied by means of N2 and CO2 adsorption, ultimate analysis, XPS, TPD and SEM. XPS and TPD spectra of the ACs have suggested the presence of aromatic rings
and carbon-oxygen functional groups in the solid surfaces. The potential use of the ACs for the removal of acetaminophen (paracetamol),
salicylic acid and benzoic acid has been investigated at different pH, temperature and contact time. The adsorption equilibrium
data have been correlated to Langmuir isotherm model. The thermodynamic study has been developed, the values of ΔH, ΔG, and ΔS have been calculated and they indicated that the processes are endothermic for acetaminophen and exothermic for salicylic
and benzoic acids. The analysis of the kinetic experiments showed that the effective diffusivities are low; 10−12 to 10−11 cm2/s, and they are the corresponding to intraparticle mass transfer, which appears as the controlling step for the net adsorption
processes. 相似文献
11.
A. M. Ryzhakov M. S. Gruzdev D. F. Pyreu E. V. Kozlovskii R. S. Kumeev 《Russian Journal of Coordination Chemistry》2010,36(8):565-571
The formation of mixed-ligand complexes HgEdtaIm2−, HgEdtaL3−, HgEdtaHL2−, and (HgEdta)2L5− (L is histidine, lysine; Im is imidazole) was studied by calorimetry, pH-metry, and NMR spectroscopy. The thermodynamic parameters
(logK, ΔrG
0, ΔrH, Δr
S) for the reactions of complex formation at 298.15 K and ion strength of 0.5 (KNO3) were determined. The most likely coordination mode for the complexone and amino acid in the mixed complexes was identified. 相似文献
12.
The effect of cosolvent on micellization of hexadecyltrimethyl ammonium bromide (CTAB) in aqueous solutions was studied. The
conductivity of a mixture (cosolvent + water) as function of CTAB concentration was measured at different temperatures. Ethylene
glycol and ethanol were used as a cosolvent. The conductivity data were used to determine the critical micelle concentration
(CMC) and the effective degree of counterion dissociation of micelle in the temperature range 303.2 to 313.2 K. In all the
cases studied, a linear relationship between log([CMC]mix/mol dm−3) and the mass fraction of cosolvent in solvent mixture has been observed. The free energy (ΔG
mic
0
), enthalpy (ΔH
mic
0
), and entropy (ΔS
mic
0
) of micellization were determined using the temperature dependence of CMC. The dependence of these thermodynamic parameters
on solvent composition was determined. The standard free energy of micellization was found to be negative in all cases and
becomes less negative as the cosolvent content increases. The enthalpy and entropy of micellization are independent of temperature
in pure water, while ΔH
mic
0
and ΔS
mic
0
decrease dramatically with temperature in mixed cosolvents. Furthermore, the entropic contribution is larger than the enthalpic
one in pure water, while in the mixed solvents, the enthalpic contribution predominates.
The text was submitted by the authors in English. 相似文献
13.
Thermodynamics of mixed-ligand complexation of yttrium group lanthanide ethylenediaminetetraacetates
T. S. Krivonogikh D. F. Pyreu E. V. Kozlovskii E. S. Titova 《Russian Journal of Inorganic Chemistry》2012,57(4):634-637
Mixed-ligand complexation of yttrium subgroup lanthanide ethylenediaminetetraacetates with asparaginate, iminodiacetate, and
nitrilotriacetate ions in aqueous solution was studied by calorimetry and pH-metry. The full set of thermodynamic parameters
(logK, Δ
r
G
0, Δ
r
H, Δ
r
S) of the addition reactions of Asp2−, Ida2−, and Nta3− to LnEdta− (Ln3+ = Tb3+, Dy3+, Ho3+, Er3+, Tm3+, Yb3+, Lu3+) was determined at 298.15 K and ionic strength I = 0.5(KNO3). The change in the thermodynamic parameters of the reactions over the series of lanthanides was discussed. 相似文献
14.
G. S. Murthy M. V. Sivaiah S. S. Kumar V. N. Reddy R. M. Krishna S. Lakshminarayana 《Journal of Radioanalytical and Nuclear Chemistry》2004,260(1):109-114
The applicability of zirconium phosphate-ammonium molybdophosphate (ZrP-AMP) for the efficient removal of cesium from aqueous
acidic solutions by adsorption has been investigated. The adsorption data analysis was carried out using the Freundlich, Dubinin-Raduskevich
(D-R) and Langmuir isotherms for the uptake of Cs in the initial concentration range of 3.75.10-5-7.52.10-3 mol.dm-3 on the ZrP-AMP exchanger from nitric acid medium. The mean free energy (E) values for the adsorption of Cs were obtained from the D-R isotherm. Equilibrium adsorption values at different temperatures
have been utilized to evaluate the change in enthalpy, entropy and free energy (ΔH°, ΔS°, ΔG°). The adsorption of cesium on the ZrP-AMP exchanger was found to be endothermic.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
15.
Removal of Cu(II), Zn(II) and Co(II) ions from aqueous solutions by adsorption onto natural bentonite 总被引:1,自引:0,他引:1
In this study, the removal of Cu(II), Zn(II) and Co(II) ions from aqueous solutions using the adsorption process onto natural
bentonite has been investigated as a function of initial metal concentration, pH and temperature. In order to find out the
effect of temperature on adsorption, the experiments were conducted at 20, 50, 75 and 90 °C. For all the metal cations studied,
the maximum adsorption was observed at 20 °C. The batch method has been employed using initial metal concentrations in solution
ranging from 15 to 70 mg L−1 at pH 3.0, 5.0, 7.0 and 9.0. A flame atomic absorption spectrometer was used for measuring the heavy metal concentrations
before and after adsorption. The percentage adsorption and distribution coefficients (K
d) were determined for the adsorption system as a function of adsorbate concentration. In the ion exchange evaluation part
of the study, it is determined that in every concentration range, adsorption ratios of bentonitic clay-heavy metal cations
match to Langmuir, Freundlich and Dubinin-Kaganer-Radushkevich (DKR) adsorption isotherm data, adding to that every cation
exchange capacity of metals has been calculated. It is shown that the bentonite is sensitive to pH changes, so that the amounts
of heavy metal cations adsorbed increase as pH increase in adsorbent-adsorbate system. It is evident that the adsorption phenomena
depend on the surface charge density of adsorbent and hydrated ion diameter depending upon the solution pH. According to the
adsorption equilibrium studies, the selectivity order can be given as Zn2+>Cu2+>Co2+. These results show that bentonitic clay hold great potential to remove the relevant heavy metal cations from industrial
wastewater. Also, from the results of the thermodynamic analysis, standard free energy ΔG
0, standard enthalpy ΔH
0 and standard entropy ΔS
0 of the adsorption process were calculated. 相似文献
16.
Polymorphism of paracetamol 总被引:1,自引:0,他引:1
G. L. Perlovich Tatyana V. Volkova Annette Bauer-Brandl 《Journal of Thermal Analysis and Calorimetry》2007,89(3):767-774
The thermodynamic relationship between crystal modifications of paracetamol was studied by alternative methods. Temperature
dependence of saturated vapor pressure for polymorphic modifications of the drug paracetamol (acetaminophen) was mea sured
and thermodynamic functions of the sublimation process calculated. Solution calorimetry was carried out for the two modifications
in the same solvent. Thermodynamic parameters for sublimation for form I (monoclinic) were found: ΔG
sub298=60.0 kJ mol−1; ΔH
sub298=117.9±0.7 kJ mol−1; ΔS
sub298=190±2 J mol−1 K−1. For the orthorhombic modification (form II), the saturated vapor pressure could only be studied at 391 K. Phase transition
enthalpy at 298 K, ΔH
tr298(I→II)=2.0±0.4 kJ mol−1, was derived as the difference between the solution enthalpies of the noted polymorphs in the same solution (methanol). Based
on ΔH
tr298 (I→II), differences between temperature dependencies of heat capacities of both modifications and the vapor pressure value
of form II at 391 K, the temperature dependence of saturated vapor pressure and thermodynamic sublimation parameters for modification
II were also estimated (ΔG
sub298=56.1 kJ mol−1; ΔH
sub298=115.9±0.9 kJ mol−1; ΔS
sub298=200±3 J mol−1 K−1). The results indicate that the modifications are monotropically related, which is in contrast to findings recently reported
found by classical thermochemical methods. 相似文献
17.
N. B. Morozova P. P. Semyannikov S. V. Sysoev V. M. Grankin I. K. Igumenov 《Journal of Thermal Analysis and Calorimetry》2000,60(2):489-495
The temperature dependency of the saturated vapor pressure of Ir(acac)3 has been measured by the method of calibrated volume (MCV), the Knudsen method, the flow transpiration method, and the membrane
method. The thermodynamic parameters of phase transition of a crystal to gas were calculated using each of these methods,
and the following values of ΔH
T
0 (kJ mol−1) and ΔS
T
0 (J mol−1K−1), respectively, were obtained: MCV: 101.59, 156.70; Knudsen: 130.54, 224.40; Flow transpiration: 129.34, 212.23; Membrane:
95.45, 149.44
Coprocessing of obtaining data (MCV, flow transportation method and Knudsen method) at temperature ranges 110−200°C as also
conducted:ΔH
T
0 =127.9±2.1 (kJ mol−1 ); ΔS
T
0 =215.2±5.0 (J mol−1 K−1 ).
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
18.
Lei Zhang Hongmei Li Xueyan Liu Pingli Kang 《Russian Journal of Inorganic Chemistry》2012,57(4):622-628
Titanium dioxide nanoparticles were employed for the sorption of Ge(IV) ions from aqueous solution. The process was studied
in detail by varying the sorption time, pH, and temperature. The sorption process was found to be fast, equilibrium was reached
within 3 min. A maximum sorption could be achieved from solution when the pH ranges between 4.0 and 11.0. Sorbed Ge(IV) ions
can be completely desorbed with 2 mL of 0.3 mol L−1 K3PO4-1.0 mol L−1 H2SO4 mixture solution. The kinetic experimental data properly correlate with the second-order kinetic model (k
2 = 0.88 g mg−1 min−1 (25°C)), Reichenberg equation and Morris-Weber model. The estimated E
a
for Ge(IV) adsorption on nano-TiO2 was 19.66 kJ mol−1. The overall rate process appears to be influenced by intra-particle diffusion. The sorption data could be well interpreted
with the Langmuir and Dubinin-Radushkevich (D-R) type sorption isotherms. The D-R parameters were calculated to be K = −0.00321 mol2 kJ−2, q
m
= 0.59 mmol g−1 and E = 12.48 kJ mol−1 at room temperature. Furthermore, the thermodynamic parameters were also determined, and the ΔH
0 and ΔG
0 values indicated a spontaneous exothermic behavior. 相似文献
19.
Elhossein A. Moawed 《Chromatographia》2008,67(1-2):77-84
The effect on polyurethane foam (PUF) of washing with different concentrations of HCl (1, 3, 6, or 11.8 M) has been studied.
After washing, PUF was characterized by use of different techniques. The adsorption properties of PUF and its chromatographic
behavior in the separation and preconcentration of gold from thiocyanate solution were investigated by batch and dynamic processes.
Uptake of Au(III) was maximum after washing with 0.05–0.2 M HCl. The kinetics of adsorption of the Au(III) were found to be
rapid; the average half-live of adsorption (t
1/2) was 60 s. Average values of the thermodynamic quantities ΔH and ΔG were −40.7 and −5.9 kJ mol−1, respectively. These data indicate that adsorption of Au(III) by white PUF proceeds via both weak anion exchange and an ion-association
mechanism. PUF was verified as a good adsorbent by determination of Au(III) in spring water and in gold alloy samples. 相似文献
20.
Multiwalled carbon nanotubes-polymeric alizarin film modified electrode was made. The electrochemical behavior of levofloxacin
hydrochloride on modified electrode was studied with cyclic voltammetry, linear sweep voltammetry and chronopotentiometry.
The results indicated that the electrical oxidation of levofloxacin hydrochloride on MWNT-PAR electrode, in HAc-NaAc buffer
solution at pH 4.2 was irreversible and was controlled by diffusion. Some important parameters m, n, D, E
D, ΔS
rc and ΔH
rc of the electrochemical process were evaluated. Good linearity relationship between peak current and its concentration in
the range of 5.0 × 10−6–1.0 × 10−4 mol l−1 was found, of which the equation was I
p(A) = −5.456 × 10−6 0.2667c, the correlative coefficient r = −0.9976 and detect limitation was 4.0 × 10−7 mol l−1. The recovery of levofloxacin hydrochloride in levofloxacin hydrochloride injection was between 94.6 and 104.7%. 相似文献