Rapid Quality Assessment Of Environmental Water And Pharmaceutical Capsules By Surface-enhanced Raman Scatting And Chromatometry

A novel, simple and ultra-sensitive method, for rapid detection of trace malachitegreen (MG) in environmental water using cloud point extraction (CPE) coupled withsurface-enhanced Raman scattering (SERS) is described. The colloidal goldnanoparticles (AuNPs) were synthesized by reduction of chloroauric acid (HAuCl4)with trisodium citrate and were used as SERS substrates. The SERS substrates werefound to produce enhancement factors of1.52×106for MG by employing the SERSpeak at1175cm1. After the optimization of SERS conditions including the volumesof ethanol, colloidal AuNPs and HCl, the present method was linear for MG at1175cm1and1618cm1over the concentration range of0.5–35.0μg L1and2.5–40.0μgL1, with the correlation coefficients (r) of0.9971and0.9960. The limits of detection(LODs) were0.10μg L1and0.70μg L1, and the intra-and inter-day relativestandard deviations (RSDs) of detection were in the range of2.0–2.5%and1.9–3.2%at1175cm1and1618cm1, respectively. Recoveries obtained by analyzing4spikedenvironmental water samples at2levels were between93.1and106.0%.In this paper, a novel method for rapid determination of total chromium in emptycapsule based on routine dry ashing method and colorimetric method is proposed. Aportable analyzer was developed with an ultra-bright light-emitting diode (LED)emitting at a peak wavelength of520nm, a lithium battery and a non-dispersive,integrated optical design. Effects of reagent concentrations, time and temperature ofcoloration on determination of total chromium were studied respectively. Under theoptimal conditions, the calibration curves showed a good linearity in the concentrationrange of0.01～1.5mg/L of total chromium, and the correlation coefficient was0.99945. Ashing time of the samples was optimize by standard addition method, andthe results showed that the best spike recovery was97.15%at a ashing time of3h.Compared with the GB national standard method (microwave digestion-graphitefurnace atomic absorption spectrometry), the results of this method has a maximum relative standard error less than5%.