Fp 920 fluorescence detector

Determination of vitamin B1 (thiamin), vitamin B2 (riboflavin), and vitamin B3 (niacin) was performed using high-performance liquid chromatography (HPLC). Vitamins B1 and B2 were analyzed according to the in-house methods of INMU-TM-FCH-08 based on AOAC Method Nos. 942.23 and 970.65, respectively. The HPLC system is composed of an FP-920 fluorescence detector (JASCO International Co., Ltd., Tokyo, Japan), an LC-20AT pump (Shimadzu Scientific Instrument, Columbia, MD, USA), a Luna C18(2) 100A column (5 µm, 250 × 4.6 × 10⁻³ m, Phenomenex, Torrance, CA, USA), and an isocratic solvent system (50% (v/v) methanol) operating at a flow rate of 1.0 mL/min [19 (link)].
Vitamin B3 was determined by an in-house method based on AOAC (2019) 961.14. The HPLC system is composed of an 1100 series G1314B variable wavelength detector (VWD) UV detector (Agilent Technologies, Santa Clara, CA, USA), a 1200 series G1310A isocratic pump (Agilent Technologies, Santa Clara, CA, USA), a Luna C8(2) 100A column (5 µm, 250 × 4.6 × 10⁻³ m, Phenomenex, Torrance, CA, USA), and an isocratic solvent system (15% (v/v) methanol) operating at a flow rate of 1.0 mL/min [20 (link),21 (link)].

SEC was performed out on an HLC-8120 system (Tosoh, Tokyo, Japan) equipped with a combination of TSKgel AW-4000 and AW-2500 columns (150 mm × 6 mm ID) (Tosoh), eluted with dimethylsulfoxide (DMSO) containing 10 mM LiBr at a flow rate of 0.15 mL/min at 65 °C. The polydispersity index (M_w/M_n) was calculated from a calibration curve of standard PEGs (Agilent Technologies, Wilmington, DE, USA). For SEC with fluorescence detection, the measurements were performed on a Gulliver system (Jasco, Tokyo, Japan) consisting of a DG-2080–53 degasser (Jasco), a PU-980 pump (Jasco), an AU-950 autosampler (Jasco), a CO-965 column oven (Jasco), an FP-920 fluorescence detector (excitation wavelength: 488 nm, emission wavelength: 515 nm) (Jasco), an RI-2031 Plus refractive index detector (Jasco), and a combination of TSKgel α-4000 and TSKgel α-2500 columns (300 mm × 7.8 mm ID) (Tosoh). The solutions (50 μL) were injected into the SEC system, and the system was eluted with a mixture of water and DMSO (volume ratio 50:50) at a flow rate of 0.3 mL/min at 40 °C. ¹H NMR spectra were recorded on a Bruker Avance III 500 MHz spectrometer (Bruker BioSpin, Rheinstetten, Germany). FTIR spectra were recorded on a Spectrum 100 FTIR spectrometer (Perkin Elmer, Wellesley, MA, USA). The sample powder was mixed with KBr and pellets were prepared for FTIR measurements.