Table 1

Tablet sample#	Founded FA concentration in test sample solution (µg/mL)	STDV/RSD%	Added FA concentration in standard addition/recovery test sample solution (µg/mL)	Recovered FA concentration in standard addition/recovery test solution (µg/mL)	Recovery rate (%)
1	0.992	0.00951/0.958%	0.500	0.500	100%
2	0.959	0.0230/2.40%	0.500	0.518	104%
3	1.01	0.0285/2.82%	0.500	0.511	102%

Table 1: Results of MIP-EW-OFCS analyzing FA in vitamin B complex tablet*

*Sample and sample preparation: A Vitamin B50 complex from a local pharmacy store was used as a sample. A tablet of this vitamin B50 complex product has a claimed 400 µg of vitamin B9. Each tablet was mixed with 400 mL DI water to make a test sample solution. Vitamin B9 concentration in the obtained test sample solution is 1.00 µg/mL.

Tables at a glance

Table 1

Figures at a glance

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

FIGURE 1

Figure 1: A diagrammatic drawing show the process of a FA templated Chitosan MIP synthesizing, washing out FA template and selective re-adsorption of FA into the template

FIGURE 2

Figure 2: Optical fiber EW absorption spectrum recorded during washing FA template molecules out of the MIP membrane coated on a BOFP. The reference light intensity was recorded when the newly made MIP was just inserted to DI water. During the washing off process, FA molecules washed out, and a negative absorption spectrum was resulted.

FIGURE 3

Figure 3: Optical fiber EW absorption spectra recorded with a bare BOFP exposed to a 10.0 µg/mL FA standard solution (spectrum A), a Chitosan non-MIP coated BOFP exposed to a 10.0 µg/mL FA standard solution (spectrum B), and a Chitosan MIP coated BOFP exposed to a 2.00 µg/mL FA standard solution (spectrum C). one single BOFP was used to reording the spectra.

FIGURE 4

Figure 4: Time response of a MIP-EW-OFCS alternatively exposed to DI water and a 1.00 µg/mL FA standard solution, repeatedly. This test result demonstrates the sensor’s reversibility and response time. The signal goes down at around 12 min was the result of mistake in operation.

FIGURE 5

FIGURE 6

Figure 5: Spectral response of MIP-EW-OFCS of this work to FA standard solution of different concentration (Figure 5 (A)). The spike at around 284 nm was caused by a light intensity spike from DH-2000 light source. It is not FA’s absorption spectrum. The relationship of baseline-shift corrected absorbance value with FA concentration is showing in Figure 5 (B).

FIGURE 7

Figure 6: Spectral responses of the MIP-EW-OFCS exposed to standard solutions of different substances. The concentration of the substances tested is also given in this graph.