Table 1.

Characteristics of 4-[¹⁰B]borono-2-[¹⁸F]fluoro-l-phenylalanine (l-[¹⁸F]FBPA) preparations separated by high-performance liquid chromatography using 10 different eluents

Eluent	n	Volume	l-[18F]FBPAa		RCPb	l-BPAc	pH
		mL	GBq	GBq/mmol	%	%
(1) 0.1% AcOH water	3	16.2 ± 1.8	1.21 ± 0.04	71.4 ± 7.2	97.2 ± 1.1	0.97 ± 0.36	3.3 ± 0.3
(2) 0.01% AcOH water	4	11.9 ± 1.2	1.06 ± 0.20	66.4 ± 6.4	98.5 ± 1.0	0.43 ± 0.17	3.9 ± 0.2
(3) Saline	2	22.3	1.32	66.4	98.7	0.97	6.0
(4) 0.01% AcOH saline	9	24.0 ± 3.0	1.18 ± 0.19	86.6 ± 23.8	98.9 ± 0.8	0.87 ± 0.71	3.8d
(5) 1% EtOH, 0.01% AcOH saline	1	20.3	1.35	50.9	98.7	2.08	3.8
(6) 0.01% AcOH, 5 mM phosphate-buffered saline	3	13.8 ± 2.2	0.95 ± 0.05	83.0 ± 24.9	99.6 ± 0.1	0.26 ± 0.23	6.1 ± 0.1
(7) 0.01% AcOH, 1 mM phosphate-buffered saline	3	15.3 ± 0.7	1.22 ± 0.17	60.1 ± 12.3	99.5 ± 0.2	0.72 ± 0.40	4.4 ± 0.1
(8) 10 mM phosphate-buffered saline	2	14.1	1.51	72.5	97.0	0.55	6.8
(9) 5 mM phosphate-buffered saline	3	15.8 ± 1.3	1.14 ± 0.04	71.7 ± 1.3	98.0 ± 0.9	0.32 ± 0.06	6.8 ± 0.0
(10) 1 mM phosphate-buffered saline	8	13.2 ± 3.3	1.12 ± 0.14	92.8 ± 31.4	98.0 ± 0.5	0.41 ± 0.23	6.7 ± 0.0

Data are average ± standard deviation

^al-[¹⁸F]FBPA obtained at the end of synthesis was normalized to that produced by 120-min irradiation

^bRadiochemical purity (RCP) was determined based on HPLC analysis

^cContamination (moles) of 4-[¹⁰B]borono-l-phenylalanine (l-BPA) is expressed as a percentage against the mass of l-FBPA.

^dn = 2