Below find three documents related to special projects

Instruments Available for Special Projects
Ideas for Special Projects
Suggestions for HPLC Projects, CH 461& 461H

Instruments Available for Special Projects

1. Agilent 240 FAAS and 240 Z GFAA atomic absorption spectrophotometers

We have hollow cathode lamps for 20 - 25 elements including Cu, Na, Zn, Pb, Tl, Mn, K, Mo, Al, V, Mg, Si, B, Ca, Ag, Cd, Zr, Cr, Li, Sr, Rb, Co, As, Se, Te.

2. JY model 2000 inductively coupled plasma emission atomic spectrometer.

For atomic emission measurements of metals and a few non-metals including As and Se. This instrument is well suited for measuring many elements in a short period of time and in general provides better detection limits than the flame AAS for transition metals.

3. Cary  219,  Agilent/HP diode array spectrophotometers.

For solution molecular absorbance determination of inorganic and organic species

4. Perkin Elmer LS50B and Aminco-Bowman Series 2 Luminescence spectrometers.

Configured to perform fluorescence measurements, phosphorescence measurements, lifetime measurements (t > 1 ms), and excitation, emission, and synchronous scans. For solution molecular fluorescence determination of inorganic and organic species.

5. Agilent 1260 High Performance Liquid Chromatographs (HPLC).

The three chromatographs are equipped with reverse phase columns and UV/visible spectrophotometric detectors. For analysis of mixtures of non-volatile organic species. One system has a DAD detector, two have variable wavelength detectors.  All three are gradient instruments.

6.  HP 5890 Gas Chromatographs with FID detectors.

For analysis of mixtures of volatile organics

7. Nicolet 510P and 5PC and a 6700 high resolution Fourier Transform Infrared Spectrophotometers

For determination of organics

8. Princeton Applied Research model 264A Voltammetric Analyzers

For determination of electroactive species with dc or pulse polarography or anodic stripping voltammetry

9. Orion pH meters

With glass pH electrodes and fluoride and bromide ion-selective electrodes

10. GC/MS

Hewlett-Packard 5890 Series II gas chromatograph with a 5971 mass selective detector and an OI Analytical purge and trap apparatus.

11. Size Exclusion HPLC.

Based on HP model 1050 high pressure pump, an non-aqueous size exclusion column, and a Waters model R401 Differential Refractive Index detector. For separation and detection of high molecular weight species such as polymers.

12. Shimadzu DCS-50 Differential Scanning Calorimeter.

A Few Ideas for Special Projects

1. Vitamins in tablets or food products

2. Compounds (fragrances) in perfumes or cosmetics

3. Pesticides or fertilizers in soil

4. Active ingredients from any drug store shelf product

5. Metals in food, petroleum products, water, or biological (blood, urine, plant, animal) samples

6. Additives in food products

7. Enzymes or substrates (glucose, lactate) in biological fluids.

8. EPA approved procedures for volatiles or semi-volatiles in drinking water by GC/MS.

SUGGESTIONS FOR HPLC PROJECTS

This document is important to read if your special project involves the use of HPLC

1. Summarize the critical literature information:

column: stationary phase (e.g., reverse phase), particle size, length

mobile phase: exact composition including any additives

detector: type and conditions (e.g., wavelength)

sample preparation:

2. Prepare separate stock solutions of analytes. First chromatograph each analyte separately to establish clearly the retention time and purity. Next, make a mixture and chromatograph to ensure that the resolution is adequate.

3. Obtain an absorption spectrum of the stock solution of each analyte to be sure of the optimum wavelengths. Often a wavelength of 254 nm is used in a literature reference because the detector was based on a Hg lamp. With our Agilent detectors, we can choose any wavelength between 200 and 800 nm.

4. The column could have become contaminated by a previous user. It is prudent to purge the column for 10 or 15 minutes with 100% methanol or a less polar solvent to wash off strongly retained less polar compounds. A purge with 100% H₂O is sometimes useful. Always equilibrate your column with your final solvent for at least 15 minutes and until the baseline is stable.

5. If your sample preparation involves a cleanup step such as solvent extraction or solid phase extraction (SPE), thoroughly test the procedure with your standard or standard mixture before proceeding to the sample. It is important to evaluate the recovery and precision of recovery of sample preparation procedures. Many times no analyte has been found in a sample because of a faulty sample preparation procedure.  For SPE, check with a standard the solution that first comes through for analyte and also do a second elution of the column to see if analyte has been left on the column.  

6. All sample solutions should be filtered with a sub-micron syringe filter before injection on the columns. The guard column is easily plugged by particulates.

7. To minimize solvent peaks, your final dilutions of standards or samples should be made with the mobile phase where appropriate.

8. List all run parameters at the beginning and end of a day so there is a clear record of the HPLC experimental conditions.

9. Indicate all analyte species that could ionized and the approach used to minimize ionization.