Preconcentration volume

I. Ferrer, M. C. Hennion and D. Barcelo, Immunosorbents coupled on-line with liquid chromatography/atmospheric pressure chemical ionization/mass spectrometry for the part per trillion level determination of pesticides in sediments and natural waters using low preconcentration volumes , Anal. Chem. 69 4508-4514 (1997). 

Figure 5.10 Trace analysis of borate. Separator conductivity regenerant 25 mmol/L TMAOH column lonPac ICE-Borate eluent 25 mmol/L +15 mmol/L mannitol concentrator column methanesulfonic acid + 60mmol/L mannitol TBC-1 preconcentrated volume 160mL flow rate 1 mL/min detection suppressed peaks 500 ng/L borate (as boron) (1).

Figure 10.82 Gradient elution of anions in a spiked high-purity water sampie. Separator coiumn ionPac AS17-C coiumn dimensions 250 mm X 2 mm i.d. eiuent KOH gradient flow rate 0.25 miVmin detection suppressed conductivity preconcentrated volume 25 mL ...

H2SO4 flow rate 0.25 mL/min detecdon suppressed conductivity preconcentrated volume 40mL peaks <10ng/L each of sodium (1), ammonium (2), and trimethylamine (3). 

Figure 10.118 Analysis of a cooling water conditioning agent in a cooling tower circulation water. Chromatographic conditions see Figure 10.117 preconcentrated volume 2mL peaks (1) polyphosphonate, (2) chloride, and (3) sulfate.

AMC-1 preconcentrated volume 2.4 mL detection suppressed conductivity peaks (1) fluoride, (2) carbonate, (3) chloride, (4) unknown component (5) unknown component (6) nitrate, (7) orthophosphate, and (8) sulfate. 

Figure 10.140 Separation of anions in dime-thylformamide after matrix elimination. Separator column Metrosep Anion Supp 1 eluent 4mmol/L Na COa flow rate 1.2 mlVmin detection suppressed conductivity preconcentrated volume 250 pL concentrator...

Figure 10.141 Trace analysis of a cation standard after matrix elimination. Separator coi-umn lonPac CS12A eluent 11 mmol/L H2SO4 flow rate 1 mlVmln detection suppressed conductivity preconcentrated volume 2 ml concentrator column lonPac CG12A peaks ...

Table 10.20 Detection limits for cations in clean room air with an automated system for analyzing air (based on a gas volume of 10 L and a preconcentrated volume of 5 ml).

Figure 10.153 Trace analysis of sulfur dioxide, conductivity preconcentrated volume 5mL Separator column lonPac AS4A eluent concentrator column TAC-LP1 peaks 10 nL/L...

The use of LOV allows the bead injection process, so that the replacement of the resin packing was performed automatically. Contrary to the longer manual protocol to isolate Sr which lasts days, the automatic separation and preconcentration system allowed analyzing up to five samples per hour depending on the preconcentrated volume. The analytical protocol started with the automatic filling of the microcolumn with Sr-resin. Then it was conditioned with 2 ml of 8 mol/1 nitric acid. Once the column was ready, a variable volume of sample was dispensed toward the column. An additional volume of 0.5 ml of conditioning solution was propelled in order to eliminate interferences. After that, the elution of Sr was carried out dispensing 5.1 ml of 0.01 mol/1 nitric acid. For the radiostrontium quantification, the eluate was dried and measured in a LBPC. 

The separation of cations is usually carried out on lonPac CS12A with sulfuric acid or methanesulfonic acid as an eluant. For anion analysis, carbonate-selective anion exchangers such as lonPac AS12A or AS14 have proved to be suitable. Alternatively, gradient elution on lonPac AS 11 can be used. As a matter of principle, 2-mm columns are utilized in order to reach the required sensitivity. With a gas flow of 1 L/min, sampling times are between 10 and 40 minutes the preconcentrated volume ranges from 1 mL to 10 mL. Metal cations are rarely detected in clean room air because they are usually bound to particles. Because... 

Separator column lonPac CS12 eluant 10 mmol/L methanesulfonic acid flow rate 1 mL/min detection suppressed conductivity preconcentrated volume 5 mL concentrator column TCC-LPl peaks 11 nU/L ammonia (1) as ammonium. 

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