Standard solutions preparation

Standard solutions. Prepare, by appropriate dilution of standardised stock solutions of lead, cadmium and copper(II) ions, mixed aqueous standards of Pb2+, Cd2+ and Cu2+ containing the following concentrations of each metal ion 0.4, 0.6, 0.8 and l.OmgL-1 (Note 2). 

Standard solutions. Prepare different concentrations of standard solutions by dilutions of the stock solution with the injection solution. 

The standard curve is the plot of an instrument s readout vs. concentration, the data for which are the results of measuring a series of standard solutions prepared for the experiment. 

Fig. 3.128. Effect of solvent strength on the chromatograms of a standard solution prepared by dissolving /1-CD ([/1-CD] = 9.5 mM) and the commercially available dediazoniation products 4-nitrophenol ([PNBOH] = 2.00X104 M), nitrobenzene ([NBH] = 1.98X10-4 M and 4-chloro-nitrobenhenzene ([PNBC1] = 1.99X10 4 M). (a) Mobile phase MeOH-water (75 25, v/v), (b) ACN-water (75 25, v/v). Reprinted with permission from C. Bravo-Diaz et al. [177].

When using standard solutions prepared on the basis of activities calculated from these activity scales, and provided there is no interfierence and that the prelogarithmic term in the E versus log a dependence is Nernstian or at least accurately known and constant, the sample activity can be determined from the ISE potentials obtained in the sample and in a standard solution (see (4.13), p. 74-6). 

The extracted blank spiked with analyte is an aliquot of blank matrix that is extracted and spiked with the appropriate neat standard solution prepared to be equivalent to an extracted standard. 

Protein concentration can also be determined by measuring the intrinsic fluorescence based on fluorescence emission by the aromatic amino acids tryptophan, tyrosine, and/or phenylalanine. Usually tryptophan fluorescence is measured. The fluorescence intensity of the protein sample solution is measured and the concentration is calculated from a calibration curve based on the fluorescence emission of standard solutions prepared from the purified protein. This assay can be used to quantitate protein solutions with concentrations of 5 to 50 (J-g/ml. 

Protein standard solution prepared using the purified protein (see recipe)... 

Standard solution Prepare as directed for the Standard preparation in the Assay. 

After initial calibration has been completed, it must be verified with a second source standard, which has been prepared from material coming from a different source (different manufacturer or lot number). This QC measure, called the second source confirmation, allows detecting errors in the initial calibration standard solution preparation and prevents a systematic error in compound quantitation. Only after this initial calibration verification (ICV) standard has also met its own acceptance criteria may the analyst start analyzing samples. 

Dealing with the chemical issues is usually much more demanding. In a typical chemical measurement there are two main components to the chemical chain of comparisons, as illustrated in Fig. 1. One component is established by measuring the response from one or more chemical standard(s), often in the form of standard solutions, prepared from pure substance RMs. The identity, purity, and stability of the standards are important issues. The calibration factor Fc and its uncertainty, Uc, describe this part of the chain. Such methods are often called ratio methods and include most of the... 

For both consistency over each day, and to check day-to-day reproducibility, it is very useful to analyse at regular intervals either synthetic standard solutions, prepared in an appropriate matrix, or, better still, standard or certified reference materials, which contain precisely known amounts of the elements or species of interest. Routine long-term time-plots of the results of such regularly repeated analyses are very useful in showing up errors arising as a consequence of hitherto unrealized procedural changes. 

Density values for the samples are dioctyl phthalate, d = 0.981 g/mL dibutyl phthalate, d = 1.043 g/mL and dimethyl phthalate, d = 1.190 g/mL. There should be four standard solutions prepared in this activity. 

Standard Solutions Prepare a series of lead standard solutions serially diluted from the Standard Lead Solution. Pipet 2, 5, 10, and 20 mL, respectively, of Standard Lead Solution into separate 100-mL volumetric flasks, add 1 mL of nitric acid, dilute to volume, and mix. The Standard Solutions contain, respectively, 0.20, 0.50, 1.00 and 2.00 pig of lead per milliliter. 

Standard Solution Prepare a series of Standard Solutions as follows Transfer 100 mg of glycolic acid, previously dried in a desiccator at room temperature overnight and accurately weighed, into a 100-mL volumetric flask, dissolve in and dilute to volume with water, and mix. Use this solution within 30 days. Transfer 1.0, 2.0, 3.0, and 4.0 mL, respectively, of this solution into separate 100-mL volumetric flasks, add sufficient water to each flask to make 5 mL, then add 5 mL of glacial acetic acid, and dilute to volume with acetone. 

Toluene Standard Solutions Prepare five working standard solutions with concentrations of 10, 50, 100, 250, and 500 pg/mL by quantitatively diluting Toluene Stock Solution with methanol. 

Standard Solution Prepare this solution in the same manner as the Sample Solution, but use 6.0 mL of Standard Arsenic Solution (see Arsenic Limit Test, Appendix IIIB) in place of the sample. 

Standard Solution Prepare a 6% solution of USP Glyceryl Behenate Reference Standard in chloroform. 

Preparation of Standard Solutions Prepare a standard solution of each of the organic compounds to be quantitated in Hydrochloric Acid (known to be free of interfering impurities) at approximate concentrations of 5 mg/kg, or within 50% of the concentrations in the samples to be analyzed. 

NDPA Standard Solution Prepare the initial solution as described above, but containing 250 p,g of A-nitrosodi-A-propylamine (NDPA) per milliliter of anhydrous ethanol. 

Standard Solutions Prepare chromatographic standards by dissolving accurately weighed amounts of commercial ethylene glycol and diethylene glycol, previously purified by distillation if necessary, in water. Suitable concentrations range from 0.2 to 1 mg of each glycol per milliliter. 

Standard Solutions Prepare a Dimethyl Sulfoxide Standard Stock Solution in tetrahydrofuran containing 0.25 mg/ mL. Dilute the Dimethyl Sulfoxide Standard Stock Solution quantitatively and stepwise to obtain Standard Solutions containing 0.005, 0.001, and 0.0005 mg of dimethyl sulfoxide in each milliliter. 

Standard Solution Prepare an aqueous solution having known concentrations of 10 mg/mL of sucrose (reference standard material is available from NIST) and 10 mg/mL of maltose (available from Sigma Chemical Co.). 

Standard Solution Prepare a solution of toluene in octyl alcohol containing approximately 50 p,g/mL, and calculate the exact concentration (CR) in percent (w/v). 

Internal Standard Solution Prepare a solution containing about 3 mg of hexadecyl hexadecanoate (Aldrich, or equivalent), accurately weighed, in each milliliter of n-hexane. 

Internal Standard Solution Prepare an aqueous solution of USP Fructose Reference Standard having a concentration of 100 mg/mL. 

Fructose Internal Standard Solution Prepare a solution of fructose to be used as an internal standard by transferring 50 g of commercial grade (3-D(-)fructose powder to a 500-mL volumetric flask, and dissolve in and dilute to volume with water. 

Of the two terms, reference materials and standards, the latter has so many meanings that care needs to be taken in its use. For example, is the analyst talking about the standard of the work i.e. the analysis), the standard solutions prepared or the standard method used. Reference material has a much less ambiguous meaning in the analytical laboratory. 

Standard Solutions. Prepare standard solutions of paracetamol as described in die colorimetric method, above. 

A. Huggett et ah, J. Chromat, 1981, 209, 61-16. Standard Solutions. Prepare standard solutions of paracetamol in plasma as described for the colorimetric method, above. 

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