From the adsorptive precipitation of SCN−, tetrachloro-tetrabromofluorescein (TBTCF) and Ag+, we found in-situ embedment of TBTCF into growing silver thiocyanate particles to form ternary electronegative inclusion material. The composition, size and phase of the material were determined by spectrophotometry and ICP and characterized by XRD, SEM, etc. The results showed that in-situ inclusion particles {[Ag(SCN)]m(TBTCF)}n2n− (m = 33 ± 11) were formed. The inclusion particles adsorbed cationic dyes selectively and rapidly. A representative cationic dye, ethyl violet (EV), was used to investigate the performance of the ternary inclusion particles and the mechanism involved. The equilibrium adsorption capacity of the Ag(SCN)/TBTCF inclusion particles is 202 mg/g EV, over 14 times higher than absorption to the silver thiocyanate–only particles and slightly more than activated carbon. Moreover, the adsorption approached the equilibrium in 10 min, which is much less than that with activated carbon in about 2 h. In this work, a simple preparation method of the inclusion material as dye adsorbent was established and it will play an important role in the removal or recovery of cationic organic substances from aqueous.

The light-absorption ratio variation approach (LARVA) which produces an outstandingly increasing of analytical sensitivity was applied to the quantitative detection of ultramicro amounts of Mn(II) by light-absorption spectrometry using the competitive replacement complexation among 1,5-di(2-hydroxy-5-sulfophenyl)-3-cyanoformazan (DSPCF), Zn(II) and Mn(II) in the presence of o-phenanthroline (OPTL). Not only masks OPTL foreign metal ions but also seriously sensitize the competitive complexation. All the binary and ternary complexes were characterized by the break point approach. Results have shown that the limit of detection (3δ) of Mn(II) is only 0.7 ng ml−1. This method has been applied to analysis of water quality with satisfactory results.

The complexation of cetyltrimethylammonium bromide (CTAB) with sodium dodecyl sulfate (SDS) with sodium dodecyl benzene sulfonate (SDBS), with tetraiodophenolsulfonphthalein (TIPST) as a spectral substitute was investigated at pH 5.89 and 8.30 by the microsurface adsorption—spectral correction (MSASC) technique. The aggregations of TIPST, SDS, and SDBS on CTAB obeyed the Langmuir isothermal adsorption. The aggregates TIPST–CTAB, TIPST2–CTAB3, SDS3–CTAB2, and SDBS3–CTAB2 were formed at 20 °C and the binding constants of all the aggregates were determined. The replacement of TIPST-binding CTAB monomer with SDS or SDBS at pH 5.89 was applied to the quantitative determination of anionic detergent (AD) in water with satisfactory recovery.

The light-absorption ratio variation approach (LARVA) has been established and applied to the determination of Co on the ng ml−1 level with 1, 5-di(2-hydroxy-5-sulfophenyl)-3-cyanoformazan (DSPCF) at pH 9.33. Competitive replacement complexation (CRC) among DSPCF, Zn(II) and Co(II) as described was used to improve the analytical selectivity. The determination of the complex formation constants was also improved. Results have shown that ΔAr−1 (where ΔAr is the light-absorption ratio variation) is linear in the range of Co(II) between 10 and 200 ng ml−1. The limit of detection (3δ) of Co(II) is only 3.7 ng ml−1. The combination of CRC and LARVA has been applied to the analysis of water quality with satisfactory results.

The non-chemical bond interaction between small molecule and macromolecule coming from the electrostatic attraction obeys the Langmuir assembly. The interaction of 1,5-di(2-hydroxyl-5-sulfophenyl-)-3-cyanoformazan (DSPCF) and three kinds of proteins: bovine serum albumin (BSA), α-globulins (Gb) and ovalbumin (OVA) at pH 1.83 has been investigated and then sodium dodecyl benzene sulfonate (SDBS) was added to replace the DSPCF binding in protein. The microsurface adsorption-spectral correction (MSASC) technique and the break point approach were both used to characterize the aggregates. Results showed that the products: SDBS99BSA, SDBS50OVA and SDBS25Gb at 30 °C and SDBS90BSA, SDBS40OVA and SDBS20Gb at 40 °C are formed.