EPA 1664 Standards

EPA 1664 Standards

StepSaver - New and Improved

Convenient Snip & Pour® PTFE Tubes.

Just snip the top of the PTFE tube and pour the contents into the sample container or extraction apparatus. The precise volume of HEM is delivered to the LCS or Matrix Spike sample. HEM contents do not adhere to the sides of the single-use PTFE tube. Inexpensive Snip & Pour tubes eliminate pipets and require no warming prior to use. Twenty 10mL tubes per pack. Each G3025 tube contains 40mg of extractable HEM per 10mL aliquot while each G3026 tube contains 10mg extractable HEM.

Oil and grease standards are also available in 30mL screw-cap bottles.

Item No. Description
G2018 SPE - O/G Standard, 5mL tubes, 40mg HEM, 20pk
G3004 SPE - O/G Standard, 10mL tubes, 4mg HEM, 20pk
G3020 SPE - O/G, 9X30mL Bottles, HEM at 40mg (w/v) in Ace
G3021 SPE - O/G Standard, 10mL tubes, 2mg HEM, 20pk
G3023 SPE - O/G MDL Standard, 10mL tubes, 7mg HEM, 20pk
G3024 SPE - O/G MDL Standard, 10mL tubes, 5mg HEM, 20pk
G3025 SPE - O/G Standard, 10mL tubes, 40mg HEM, 20pk
G3026 SPE - O/G Standard MDL, 10mL tubes, 10mg HEM, 20pk
G3027 SPE - O/G Standard, 200mg/L, 10mL units, 20pk
G3032 SPE - O/G Standard, 100mg/L, 10mL, 20pk


Is this hexadecane or steric acid?

This standard is a 50/50 mixture of both hexadecane and stearic acid.

Hi, Is this HEM disssolved in acetone

Yes it is. These tubes contain 250 mg HEM dissolved in 10 mL acetone.

When treating this product with only hexanes, such that I am only extracting nonpolar components, should my reference value be 20mg? This would be because only the hexadecane is being extracted.

Hexane will extract both hexadecane and stearic acid. Your final result should be 40 mg extracted from this standard. Even though the carboxylic acid functional group adds a certain amount of polarity to the end of the chain, the non-polar carbon chain allows for solubility in organic solvents. If you use the silica gel treatment (SGT-HEM) prior to evaporation of hexane, that will give you selectivity between the stearic acid and hexadecane, with a final result of 20 mg.

Do I need to extract the stearic acid as well as hexadecane in order to achieve 100% recovery?

To comply with EPA method 1664 you must use the a standard with 20 mg hexadecane and 20 mg stearic acid, which gives 40 mg total HEM. The total recovered amount must be in the range of 83-101% for the initial precision and recovery standard or 78-114% for the ongoing precision and recovery standard.

What is the difference between 10mL and 5mL tubes? Are there instructions for use?

The important difference is the amount of analyte contained in each one. That amount is given in the product description. There are some tubes that have the same amount of analyte present in 5 mL and 10 mL of acetone. Which one you use is dependent on the amount of volume available to add and user preference.

Will freezing the Standard effect the recovery of the Standard

The storage conditions for this standard are listed as ambient conditions. Refrigerated or frozen conditions can cause the target analytes to fall out of solution. If particulate is observed in the tube, allow it to warm to room temperature and wait for all particulate matter to redissolve.

We have one of your systems. Is the Hexadecane std for mineral O&G recovery and the stearic acid std for animal&vegetable O&G recovery?

The Laboratory Control Standard (LCS) specified in EPA Method 1664 is 20 mg hexadecane and 20 mg stearic acid dissolved in acetone and is to be spiked into the aqueous sample. The stearic acid was chosen to simulate biological sources of oil (vegetable and animal oils and fats) and hexadecane was chosen to simulate petroleum sources of relatively low volatile oils (heavy fuel oils and lubricating oils).

Calculation of Sample Matrix Spike using the above standard, if our sample is in mg.\\L or ppm?

This product contains 7 mg of HEM. If this standard was spiked in 1 L of sample, the concentration of the spike would be 7 mg/L or 7 ppm.

Are these standards prepared with NIST traceable equipment?

This standard is prepared with NIST traceable supplies. Please visit http://www.envexp.com/coa and then follow the path down to Oil and Grease Standards, OG Standard - G3020, and select a file to see a sample COA.

Does item # G3023 (O/G MDL standard, 7mg HEM) contain equal amounts of Stearic Acid & Hexadecane? And can it be used for the SGT-HEM MDL at 3.5 mg/L?

Yes, this standard does contain equal amounts of stearic acid and hexadecane. If 3.5 mg of SGT HEM is acceptable for your procedure than it can be used for such. If you need a slightly larger amount we do offer a product that is 10 mg HEM, 5 mg of each component. This is item G3026.

What is the difference between G3025-G34 and G3025 standards?

There is no difference in the actual product. They are identical. The difference arises in the documentation that comes with it. Item G3025-G34 comes with ISO Guide 34 certification included.

When I prepare the standard using an amber sample jar, should I adjust the final result by the total volume of water in the jar?

If you adjust the final result by the amount of water in the jar you should also adjust the true value by the amount of water in the jar. Either way will yield the same final percent recovery.

What is the acceptable range for only the SGT-HEM portion of this standard (G3025)?

The method defines an acceptable range of SGT-HEM recovery as 83-116% for the initial precision and recovery (IPR) and 64-132% for matrix spikes and ongoing precision and recovery.

Is the range of uncertainty for the SGT-HEM portion of this standard (G3025) also +/- 2%?

The uncertainty for each of the individual components is ± 1%.

Is this product ISO 34 Certified?

Yes, these products carry guide 34 certification.

Is this product ISO 34 Certified?

Yes, these products carry guide 34 certification.

Is this product ISO 34 Certified?

This standard is made by a Guide 34 certified manufacturer. Please see http://www.envexp.com/coa for a sample COA for this product. Cycle through to the end of the listing to see the most current COA with ISO certification references.

I\'m not quite sure what HEM means... does this mean that when the entire contents of the tube is poured through the filter, 40mg/L of oil & grease is available to be extracted and finally calculated?

HEM stands for Hexane Extractable Material, which is the official term that is in the method instead of Oil and Grease. This standard is prepared exactly as specified in the method with 20 mg hexadecane and 20 mg stearic acid in each tube. This gives you a total of 40 mg that is available for extraction. The two different components are used so that further treatment with silica gel can give a measureable result as well.

If I use half the volume into 1L will I get back 20mg/L

That would be correct but it is not recommended to treat this standard in that manner - it should be used as a whole volume.

If I use the 40mg HEM standard for the Silica Gel portion for TPH only, should my reference value be 20mg?

Yes, the standard is 20 mg stearic acid and 20 mg hexadecane.

i have a G3020 standard.how much ml of standard from the bottle to use?

The concentration of this standard is 4 mg/mL the volume you use will depend on the final concentration desired of your working standard. The concentration of the LCS per EPA 1664 should be 40 mg/L so 10 mL of the G3020 standard per 1-L of acidified water will achieve this.

G3025S - Samples: SPE - O/G Standard, 10mL tubes, 40mg HEM, 4pk: Is this item manufactured under an ISO 17025 or Guide 34 accreditation? If nor do you have one that is?

Yes--this standard is manufactured by an ISO 17025 / Guide 34 certified laboratory.

Hello. I need a standard and a certificate of analysis for HEM and SGT-HEM. Do you have one?

There are several options available for this standard. G3025 is the most convenient. It comes in individual tubes with one measured amount on standard inside. It contains 40 mg total HEM and 20 mg SGT-HEM as specified in 1664. G3020 comes packaged as a set of nine 30 mL bottles. These contain HEM at a concentration of 4.0 mg/mL and SGT-HEM at 2.0 mg/mL. This allows you to customize the amount of standard you wish to add each time. We also offer 2 different options intended for MDL determination. G3023 is 20 tubes at 7 mg HEM, 3.5 mg SGT-HEM and G3026 is 20 tubes at 10 mg HEM, 5.0 mg SGT-HEM. All of these products will come with a certificate of analysis.

Hi Environmental Express, I purchase your 10 mg HEM standards. The certificate that comes with the standards has the concentration but not the uncertainty associated with the 10 mg. Please send to me.

The uncertainty of our cat# G3026 standard is 10mg +/- 2% HEM.

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