DIODE ARRAY SPECTROPHOTOMETER HP 8452A

Steps to run the Diode Array Spectrophotometer:

1)    Turn the UV/Vis Spectrophotometer switch on.

2)    Turn the computer on.

3)    Select Microsoft Windows 2000.

4)    Start the Chemstation by clicking the icon UV-Vis online.

5)    Go to Instrument and turn the light on.

6)    Go to file—> New Method /Load (Previous Method)

7)    Method

    —Fixed Wavelength Task: The Fixed Wavelength task allows the calculation of results from up to six wavelengths with or without back   ground correction.

·       Use wavelengths —Up to six single wavelength

·       Background correction—none
                                         single reference wavelength
                                         subtract average over a range
                                         three-point drop line

·       Data Type—Transmittance
                     Absorbance
                     Derivative 1-4

·       Display Spectrum—Sets the upper and lower wavelength limits for spectral display

—Spectrum/Peak: This task determines the maximum and minimum of the data points(y-values) in the defined wavelength range of the spectrum.

·        Data Type—Sets the Spectral Processing to the selected type

                                           —Transmittance

                                           —Absorbance

                                           —Derivative 1-4

·        Display Spectrum—set the upper and lower wavelength limits for spectral display.

·        Number of peaks—0 to 19

·        Number of Valleys—0 to 19

     —Ratio/Equation: This task calculates the result based upon a specified equation. The equation can contain absorbances from up to six wavelengths plus sample weight and volume information. The parameters are as follows:

·        Use Wavelengths: Set it to the selected values. Up to six single wavelengths.

·        Data Type: Set it to the selected values.

                                           —Transmittance

                                           —Absorbance

                                           —Derivative 1-4

·        Equation Name: Set the equation name-Numeric text

·        Equation: Set the equation parameter-Numeric text

You can use the following mathematical operators for the equation:

+,-,/,*,ABS(exp),Ceil(exp),EXP(exp),FlOOR(exp),LN(exp)

LOG (exp), SQR (exp), SQRT (exp).

·        Unit: Set the units for the result-Numeric text

·        Use sample weight and volume: Switches on the weight and volume entry fields in the Sample Information dialog box.

Checked or unchecked.

·        Prompt for sample information: Switches on the display of the Sample Information dialog box after sample measurement. Checked or unchecked.

·        Display Spectrum: Sets the upper and lower wavelength limits for spectral display.

           —Quantification: This task calculates calibration coefficients from the measured data of a set of standards, and then uses the calibration coefficients to determine the concentration of unknown sample.

·        Use wavelengths —Single wavelength value.

·        Background correction—none
                                         single reference wavelength
                                         subtract average over range
                                         three-point drop line

·        Analyte name: Set the analyte name-numeric text.

·        Calibration Curve Type: Set the calibration curve type.

                                         —linear (Beer’s law)

                                         —linear with offset

                                         —quadratic

                                         —quadratic with offset

·        Concentration: set the unit of concentration-numeric text.

·        Weight and Volume unit: Set the units of weight and volume; Switches on the weight and volume entry fields in the Sample Information dialog box-numeric text.

·        Prompt for standard information: Switches on the display of the Standard Information dialog box after sample measurement. Checked or unchecked.

·        Prompt for sample information: Switches on the display of the Sample Information dialog box after sample measurement. Checked or unchecked.

·        Data Type: Sets the Spectral Processing to the selected type

                                           —Transmittance

                                           —Absorbance

                                           —Derivative 1-4

·        Display Spectrum: Sets the upper and lower wavelength limits for spectral display.

8)    Go to Measure from the screen Menu.

·        Blank (F4) to run the blank

·        Automation Set up (F7)

9)    Go to Instrument:

·        Select sampling system—manula

                                           —Sipper

                                           —Multiple Cell

                                           —Auto Sampler

press sample to run the sample

·        Set up spectrophotometer—Wavelength range from 190-1100

                                              —Integrated time-.5 sec

·        Spectrum status

10)  Math —Absorbance: It is the default method. Absorbance spectra is             calculated using absorbance function. 

                —Transmittance: Transmittance spectra is calculated using transmittance function. 

                —Derivative: First, second, third and fourth order derivative spectra can be calculated. Derivative function is used.

                —SPline

     11) View—samples

                       —last blank spectrum

                       —math results

12) Mode—Standard

13) Config—Path: standard report

                                —data

                                —method

14) Help

15) After you are done go to instrument turn off the lamp, spectrophotometer and the computer.

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