Synthesis of a new ionic liquid for efficient liquid/liquid extraction of lead ions from neutral aqueous environment without the use of extractants

Figures & data

Table 1. Operating parameters of Perkin Elmer Optima 8000 ICP-OES spectrometer for the analysis of Pb²⁺

Parameters	Value
Plasma flow	12 L/min
Auxiliary flow	0.5 L/min
Nebulizer flow	0.2 L/min
RF power	1500 watt
Sample flow rate	1 mL/min
Sample replicates	3
Spectra line (analytical wave length)	220.353 nm

Scheme 1. Synthesis path of [C₆byp][(CF₃SO₂)₂ N].

Table 2. Working standards of the calibration curve for determinations of Pb²⁺ using ICP-OES

Standards	Concentration (mg/L)	Intensity	Regression equation
1	0.05	1269.8
2	1.05	29,261.3
3	2.05	56,616.5	y = 27730x-1.7
4	3.05	84,787.5
5	4.05	112,640.8	R^2 = 0.999991
6	5.05	139,752.2

Table 3. Frequencies and vibrational assignments of [C₆bpy][(CF₃SO₂)₂ N]

	Assignment	Frequency, cm^−1
1	ν C-H, aromatic	3132, 3072
2	ν C-H,hexyl	2950, 2870
3	δ C-H, aromatic	1960, 1849, overtone
4	ν C = C, aromatic	1636
5	ν C = N, aromatic	1464
6	ν SO2and δ SO2	1353, 1121 and 605, respectively
7	ν CF3and δ CF3	1191 and 737, 504, respectively
8	ν SNS	1050
9	ν CS	789

Figure 1. a) ¹ H NMR spectrum b) ¹³CNMR spectrum c) ¹⁹F NMR spectrum of [C₆byp][(CF₃SO₂)₂ N].

Figure 2. ESI MS+ of a) the cation, b) anion of [C₆byp][(CF₃SO₂)₂ N].

Figure 3. FTIR spectrum of [C₆bpy][(CF₃SO₂)₂ N].

Figure 4. DSC of [C₆bpy][(CF₃SO₂)₂ N].

Table 4. The concentration of Pb²⁺ before and after the extraction in the aqueous phase for each cycle at 298 K and IL

Cycle	(Ci)*aq(mg/L)	(Cf)**aq(mg/L)	CIL***(mg/L)	RSD	%E
I	0.3806	0.007	0.372	0.1543	98.16
II	0.3806	0.007	-	0.1804	98.16
III	0.3806	0.009	-	0.1154	97.64
IV	0.3806	0.008	-	0.1013	97.90

*(C_i)aq: concentration of the Pb²⁺ in the aqueous phase before extraction; **(C_f)aq: concentration of the Pb²⁺ in the aqueous phase after extraction; C_IL***: the concentration of Pb²⁺ was made only in the first round of extraction.