Bioanalytics and Bioinformatics

 

EBPI Analytics is pleased to offer Mass Spectrometry (MS) services to identify and quantify small molecule sample components. Our MS mass analyzers are modern machines with exceptional capabilities. We also offer separation methods that can be coupled with mass analysis to improve spectral resolution and allow compound identification of many environmental contaminants. High resolution Mass Analysis (HRMS) is also offered to provide ppm mass accuracy for publication and unambiguous identification purposes. Standardized sample preparation will be enforced to ensure the protection of our instruments and analysis will be run with pre-approved solvents and concentrations. Developed chromatographic separation methods will also be implemented for the same reason however, our analytical specialist will be happy to aid in supplementary method development at an appropriate cost if necessary.

Please ensure samples submitted do not contain non-volatile buffers and salts. These will interfere with analysis, may suppress ionization of sample analytes, and may contaminate or damage the instrument. If salts are present, you will need to follow a de-salting procedure. Please refer to our handout on some steps to take to avoid this.

 

Bioanalytical Services Offered at EBPI Analytics 

Gas Chromatography coupled Mass Spectrometry (GC-MS)

This technique has been used extensively to identify and quantify molecules in environmental samples, drug detection, fire detection and airport security protocols. GC-MS utilizes separation by gas chromatography followed by mass spectrometry on a triple quadrupole mass analyzer. Tandem MS experiments are available to aid in biomarker detection and identification. The instrument used at EBPI Analytics is a Bruker Scion GC-MS, purchased last year.

• Ideal for running solid, liquid and gaseous samples
• Perfect for detection of most pesticides, drug metabolites and most organic molecules
• Cost and time-effective
• Volatility is necessary for ionization.

 

High Pressure Liquid Chromatography coupled Mass Spectrometry (HPLC-MS)

This technique has also been used extensively for the identification and characterization of sample components in mixtures implements liquid separation methods and electrospray to ionize sample molecules. The standard HPLC chromatography protocol at EBPI Analytics typically uses reverse phase (RP) separation columns but normal phase (NP) and specialized columns are available if required. Electrospray ionization (ESI) coupled with an ion trap mass analyzer composes the MS analysis, which permits tandem fragmentation experiments as well as specific reaction monitoring experiments.

• Ideal for larger, non-volatile molecules and aqueous samples
• ESI is “soft” ionization technique, fragile parent molecules are detected more efficiently
• Ideal method for analysis of aqueous samples, waste water effluent, drinking water testing.

 

High Resolution Mass Spectrometry (HRMS)

This technique uses a time of flight mass spectrometer (TOF-MS) to detect and give high mass accuracy information. Accuracy in parts per million (ppm, 4 decimal places) is required for most peer-reviewed journals to confirm molecular identity.

• Necessary for unambiguous identification in certain application.
• Provides necessary accuracy for complex mixtures of similar compounds, or compounds with identical molecular formulas.

  

Things to Remember

If you are unsure about what separation and MS technique to use for your sample, please refer to our sample submission flow chart. Technique choice will be largely based on the physical and chemical properties of the analyte, as well as the sample matrix and type ie. solid/liquid.

Sample Submission Flow Chart:

 

Mass Spectrometry Guidelines and Techniques Offered

Guidelines 

It is BEST TO AVOID the use of non-volatile agents such as salts (NaCl, CaCl2, KH2PO4), detergents (SDS, Triton), chaotropic agents (Urea, Guanidinium salts) and buffers/solvents such as DMSO, glycerol, TRIS, CHAPS, HEPES, citrates, perchlorates, DMF. They will lead to poor ionization. If unavoidable, see below to remove or reduce their concentration.

If necessary then purification steps are required. Please ensure you notify EBPI Analytics of any buffers or salts used for your samples so that correct purification can be implemented. Preferred techniques include:

• Reversed phase HPLC using C4, C8, or C18 columns
• Ultrafiltration - a gentle method to purify & concentrate protein samples. Small spin columns can be purchased with specific MW cut-off filters, which allow size selection for the compound of interest.

What CAN you use?

Volatile solvents and buffers like water, ammonium hydrocarbonate, ammonium acetate, ammonium formate, acetonitrile, methanol, trifluoroacetic acid, formic acid, ammonium hydroxide, acetic acid.

Please refer to table of maximum acceptable concentrations of surfactants, buffers and salts, shown below

 

Allowable Concentrations of Buffer/Solvent Components:

Component	For ESI (mM)
TRIS	N/A
HEPES	N/A
BICINE	N/A
Urea	N/A
Guanidine, HCI	N/A
Dithiothreitol	N/A
Glycerol	N/A
n-Octyl-b-glucopyranoside	3.4
n-Octyl-sucrose	2.1
n-Dodecyl sucrose	1.9
n-Dodecyl maltoside	2.0
Octyl thioglucoside	3.2
n-Hexyl glucoside	3.8
n-Dodecyl-glucoside	2.9
PEG1000	0.5
PEG2000	N/A
Triton X-100	<1.6
NP-40	N/A
Zwittergent, 3-16	N/A
Tween20	0.81
Thesit	<1.7
SDS	<4.4
LDAO	<4.4
CTAB	<3.5
CHAPS	1.6
Sodium Cholate	2.3
Sodium Taurocholate	<1.9
Sodium Azide	3.1
NH4CHO3	N/A
NaCl	N/A
Sodium Acetate	N/A
NaHPO4	10
TFA	4.4