water and power plants in power plants water comes into contact with numerous components some of which are mentioned below · · · · · · · piping heat exchangers ion exchangers turbine blades condensers reactor pressure vessel fuel rods the protection of these components guarantees operational safety and reduces maintenance costs ion chromatography offers the possibility of determining important monitoring parameters ion exchangers ion exchangers whose correct functioning is checked by anion determinations purify the water used if the rapidly eluting anions fluoride glycolate acetate and formate can be detected this means that the ion exchangers are exhausted and must be replaced the metrosep a supp 7 250 anion-separation column separates the above-mentioned anions besides the standard anions in an isocratic run heat exchangers if concentrations of sodium are found to be too high in the water used for steam generation in the power plant this could indicate a leak in the heat exchanger
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preventing corrosion corrosion can be effectively prevented this is carried out by the addition of lewis bases which have the following effect h3o nr3 h2o nhr3 as a result of this neutralization reaction corrosion promoted by oxonium ions can be considerably reduced for ph adjustment or for making the water alkaline the following chemicals can be used among others substance ammonia diethanolamine ethanolamine hydrazine lithium hydroxide morpholine abbreviation nh3 dea eta/mea n2h4 lioh triethanolamine c4h9no tea cation determinations by ion chromatography without chemical suppression allows for the reliable determination of the amines meaning that ic can be used for controlling amine addition this addition is necessary as amines are not only consumed but also decompose for example by splitting off dinitrogen monoxide laughing gas or nitrogen and are removed in this way from the circuit control boron in the form of boric acid is added to the water of the primary circuit of nuclear pow
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cation ic system the setup of the «mic-4 advanced» the modular cation system with electronic suppression and sample preconcentration is as simple as it is effective isocratic analyses are carried out with freely selectable eluent serial double-piston 818 ic pump injection valve with ic cation preconcentration column high-performance separation column for cations which is contained in the 820 ic separation center with column heating and 819 ic conductivity detector chemical suppression is not needed as this would interfere with the determination of the transition metals in addition to the alkali and alkaline earth metals and amines chemical suppression would lead to the formation of hydroxides causing precipitation of the transition metals the preconcentration column is the interface between the ic system and «misp» metrohm inline sample preparation all sample preparation steps take place in the low-pressure part of the system outside the ic system itself the cations to be analyze
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schematic of «mic-4 advanced» key c columns d detector e eluent p pumps s standard t transfer solution «mic-4 advanced» modular cation system with electronic suppression extended by a valve sample preconcentration 800 dosino metrosep i trap 1 and transfer tubing schematic of «mic-6 advanced» key c columns d detector e eluent p pumps s standard t transfer solution «mic-6 advanced» modular anion system with chemical suppression sample preconcentration and matrix elimination extended by matrix neutralization 800 dosino metrosep i trap 1 and transfer tubing 9
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liquid handling with the 838 advanced sample processor the 838 advanced sample processor prepares samples for analysis more than 30 different sample racks are available and are automatically recognized by the sample changer sample volumes from 0.5 to 500 ml are safely handled up to 148 samples of up to 11 ml can be accommodated on the standard sample rack in ultratrace analysis the sample vessels play a significant role because as the volume of the sample vessel increases the risk of contamination and adsorption by the vessel walls decreases for example 125-ml nalgene® bottles are recommended these can be used with the 6.2041.380 sample rack special models for particular vessel types can be supplied liquid handling with the 833 liquid handling sample preparation unit the 833 liquid handling sample preparation unit corresponds to a high-capacity version of the «msm» metrohm suppressor module sample preparation takes place «inline» regeneration and rinsing take place «offline» in para
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applications determination of cations in the secondary circuit of nuclear power plants the «mic-4 advanced»-system is used for this application the standard system has been extended by the 838 sample processor with 800 dosino i trap column and the transfer tubing two «misp» techniques are used · inline calibration · inline sample preconcentration calibration the calibration values are selected so that the whole of the expected concentration range is covered the linearity of the inline calibration is excellent the correlation coefficients for all cations are >0.999 cations calibration levels of inline calibration concentrations given in ppb g/l no ion level 1 level 2 level 3 no of sample loop switchings 1 2 5 volume 10 l 20 l 50 l lithium 200 sodium 200 ammonium 50 000 eta 500 000 sample concentrations corresponding to a preconcentration volume of 5000 l lithium 0.4 0.8 2.0 sodium 0.4 0.8 2.0 ammonium 100 200 500 eta 1000 2000 5000 1 2 3 4 1 2 3 4 column metrosep c 2 250 6.1010.23
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carryover samples standards regeneration and transfer solutions partly use the same tubing within the ic system particular attention has been given to keeping carryover within the system negligible · air bubble as simple as effective a defined volume of air is aspirated between different liquid portions and transferred through the tubing system even this simple step significantly reduces carryover · rinsing the sample needle in order to prevent carryover caused by the sample needle it is assigned a special position by the sample changer and thoroughly rinsed both inside and out with a freely selectable rinsing solution if the risk of carryover is insignificant it is sufficient to rinse the needle at one of the three special positions on the sample rack liquid handling during the rinsing process is carried out by the 800 dosino · rinsing the flow path the 800 dosino is used to rinse the complete flow path of the system that comes into contact with the sample this is normally done with u
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measurement for measurements a 2000 l sample is preconcentrated the preconcentration volume depends on the expected concentrations and the matrix for measurements in the lower ppt range singledigit ppt more than 100 ml sample can be preconcentrated particular attention is given to the separation between fluoride and the rapidly eluting anions glycolate acetate and formate the metrosep a supp 7 250 column is used which separates these anions from the other standard anions in an isocratic run no 1 2 3 4 5 6 7 8 9 10 ion fluoride glycolate acetate formate chloride carbonate nitrite bromide nitrate phosphate sulfate concentration 20.21 3.36 9.67 3.10 25.51 10.73 0.20 22.32 17.79 69.65 column metrosep a supp 7 250 6.1006.630 eluent sodium carbonate eluent sample from the primary circuit of a nuclear power plant concentration ppb g/l preconcentration volume 2000 l 16
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triple determination of the sample blank 500 1000 1500 and 2000 l data security in accordance with the requirements methods can be validated and checked most statistical methods can be easily implemented and are supported by the metrodata ic net software determining blanks spiking reproducibility recovery rate variability of the retention times etc to check the present measurements four different volumes 500 1000 1500 and 2000 l were preconcentrated and a three-fold determination carried out on each the blank value was determined and subtracted the data was then used to check the linearity and reproducibility of the analysis metrohm inline calibration with fixed sample loop the use of only one standard solution and the extraordinary precision of the 800 dosino provide excellent results both under normal laboratory conditions and under the rough conditions prevailing in the power plant turbine room no ion concentration rsd 0.29 0.07 0.99 0.89 0.33 0.80 0.98 0.18 0.24 0.15 1 2 3 4
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«mic-6 advanced» anion system adapted to power-plant applications modular anion chromatography system with chemical suppression sample preconcentration and matrix elimination extended by matrix neutralization 800 dosino i trap column and transfer tubing 2.818.0110 2.819.0110 2.820.0220 2.830.0020 2.833.0020 2.833.0030 2.837.0010 2.838.0020 6.2041.380 2.800.0010 6.3032.150 6.1562.130 6.2620.150 6.1006.430 6.1011.020 6.1011.120 6.1006.310 6.1014.200 6.1805.100 6.2744.200x3 6.2744.080 6.1618.050 6.1621.000 6.1829.020 6.2820.000 6.5324.000 818 advanced ic pump 819 advanced ic detector 820 advanced ic separation center with 2 injectors and column heater 830 advanced ic interface 833 advanced ic liquid handling suppressor unit 833 advanced ic liquid handling sample preparation unit 837 advanced ic eluent degasser 838 advanced ic sample processor with 6-way injection valve and dual-channel peristaltic pump sample rack 14 x 8 oz for 125-ml bottles e.g nalgene® 800 dosino dosing unit glass 5 ml
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i onanalysis metrohm ltd ch-9101 herisau/switzerland phone +41 71 353 85 85 fax +41 71 353 89 01 www.metrohm.com info@metrohm.com subject to modifications layout by ecknauer+schoch asw printed in switzerland by metrohm ltd herisau 8.041.6003 2006-10
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