高盐样品中总有机碳含量检测方案(TOC分析仪)

analytikjenaAGanalytical solutions 01/01 SP_TOC_01_01_e Recovery of a TOC Standard after injection of a saline solutionmulti N/C 1lntroduction In the field of TOC analysis， not only wastewater or surface water， but also seawater playsan important part. The specificity of the latter is that the salt content of this matrix is veryhigh. Such salt loads， however， can also be found in chemical industry， on garbage dumpsand in electroplating industry. Analysis The aim of the investigation was to test the multi N/C analyzer to find out to what extent therecoveroyf oaf1 amg/l standard remains stable. The procedure was as 1follows：A 1 mg/l potassium hydrogen phthalate standard with an addition of 140% NaCl wasanalyzed altogether six times with 20 repeat measurements each. After every secondanalysis， a control measurement with a pure potassium hydrogen phthalate standard wastaken to keep track of the recovery. A five times determination with subsequent averaging ofthe test standard was regarded as sufficient. The mean of the 14 % NaCl blank also resultedfrom the random sampling between the salt-loaded standards. With this NPOC method， the injection volume was optimized to 500 pl. Blank+14%NaCl=1.01 mg/l In the following evaluation， first one refers to the introduced salt content， which entered thesystem through the blanks and the standards. The blank has already been taken intoaccount and subtracted accordingly. 01/01 SP_TOC_01_01_e Number of injections (500 pl each) Blank14% NaCl 1 mg/I KHP14% NaCl Salt content.absolute Salt content，total 5 1.13 mg/l 0.35g 0.35 g 20 0.92 mg/l 1.40 g 1.75g 20 1.05 mg/l 1.40 g 3.15 g 5 0.89 mg/l ---- 0.35g 3.50g 20 1.11 mg/l 1.40 g 4.90 g 20 1.07 mg/1 1.40 g 6.30 g 5 1.06 mg/l 0.35 g 6.65 g 20 1.03 mg/l 1.40g 8.05 g 20 1.10 mg/l 1.40 g 9.45g 5 0.96 mg/I --- 0.35g 9.80 g SUM： 140 From the results， first one can conclude that 140 injections with saline water got into thesystem. These contained about 10 g of salt. In addition， the comparison is to be presented showing the recovery of a standard withoutsalt load after the measurement of a saline-loaded standard. analytical solutions 01/01 SP_TOC_01_01_e ◎ 2001 Analytik Jena AG Phone +49 (0) 36 41/77-70Fax +49 (0) 36 41/77-92 79