Retention And Analysis Of Trace Compounds In Paper

Pulping and papermaking process, in order to produce a certain degree of white paper, often need bleaching or adding a certain amount of fluorescent whitening agent in stock to achieve the requirements. Currently our bleaching of straw pulp mainly through hypochlorite or chlorine bleach, and the composition of plant fiber paper is complex, and in the bleaching, agent will react with plant fiber and produce a variety of chlorinated organic compounds. Fluorescent whitening agent in paper will contact with the human body through the skin, mouth and other ways to enter the human body; chlorinated organic compounds and a fluorescent whitening agent into the human body will continuous enrich in body, and harm human health. Therefore, it is imperative to study the detection methods of trace compounds in paper.By infrared spectroscopy (FTIR), high performance liquid chromatography (HPLC) and Raman spectroscopy, the determination of trace fluorescent whitening agent VBL and 2,4,6-trichlorophenol(TCP) was studied.The micro fluorescent whitening agent VBL and TCP were studied by FTIR method, and no obvious characteristic peak appeared, so the detection sensitivity is low.The fluorescent whitening agent VBL was studied by HPLC method. Through the single factor experiment, the liquid phase chromatography conditions about fluorescent whitening agent VBL and the fluorescent whitening agent extraction method in paper were determined, then design of four factors and three levels of orthogonal experiment was used to optimize the extraction method of the paper of fluorescent whitening agent VBL, ultimately it was found that the self-made sample quality on the extraction efficiency had the greatest impact, extraction solvent volume had the second impact degree, and ultrasonic vibration time and temperature effects were minimum. Using the established method to detect 15 products purchased from the market, the presence of fluorescent whitening agent VBL were detected in the 3 products and the content was high.The TCP of the paper was studied by HPLC. Determination of trace TCP test conditions and extraction method in the paper were through the single factor experiment, then using the established method,20 kinds of real samples buy from the market were tested. TCP was detected in a printing paper, a corrugated and a napkin and its content followed by printing paper, corrugated paper, and paper napkin. Pulp for making printing paper is bleached pulp, pulp for making corrugated paper is a brown pulp, and the actual test result can indicate that corrugated TCP content and print has little difference, so it can be concluded that, with the recovery and utilization of waste paper fiber more times, harmful substances residual in the paper fiber may continue to accumulate, the TCP content will be more and more high and will eventually break through the lowest level of the provisions of the state and threat to human health, harm environment security.TCP in paper was studied by Raman spectroscopy. First through comparison the Raman spectra chart of TCP and base paper, it was found that TCP had multiple peak existing at the locations different from the base paper fiber. Three groups of peaks were selected for the detection of TCP in paper fibers, and ultimately the peaks of 190,230cm-1 had best detection effect. By comparing condition with the silver sol enhanced substrate and without enhanced substrate, the results showed that the silver sol inhibits the residual effect of TCP on the paper fiber, and the detection effect was not obvious. Through detecting the multi sample groups containing different concentrations of TCP, comparing the Raman spectra and Raman scanning image, the minimum detection line of the method was determined as 1mg/L.