United States Department of Agriculture

Agricultural Marketing Service, Science & Technology

Pesticide Data Program

SOP No.: PDP-LABOP Page 1 of 42

Title: Sample Processing

Revision: 15 Replaces: 12/01/2022 Effective: 12/01/2023

1. Purpose:

To provide standard procedures for:

• the receipt, storage, archival, and disposal of MPD Pesticide Data Program (PDP) samples 

and sample portions

• the preparation of MPD PDP samples 

• the handling of sample homogenates that are shipped to another laboratory for analysis

2. Scope:

This standard operating procedure (SOP) shall be followed by all laboratories conducting residue 

studies for PDP, including support laboratories conducting stability or other types of studies that 

may impact the program.

3. Outline of Procedure:

5. Sample Processing, Storage, and Disposal

5.1 Sample Receipt

5.1.1 Sample Inspection at Receipt

5.1.2 Prepared Fresh Commodity Acceptability

5.1.3 Sample Containers

5.1.4 Damaged Animal Tissue

5.1.5 Sample Weight Acceptability Criteria

5.1.6 Sample Viability

5.1.7 Documentation for Samples Not Analyzed

5.1.8 Missing/Late/Unacceptable Samples or eSIFs

5.1.9 Unresolved Sampling Issues

5.1.10 Paper SIFs

5.1.11 Unique Laboratory Sample ID

5.1.12 Unit Counting

5.1.13 Sample Receipt Log

5.2 Sample Storage Prior to Homogenization

5.3 Preparation and Homogenization of Fresh Produce, Animal Tissue, Nuts, and Grains

5.4 Preparation and Homogenization of Processed Commodities

5.5 Weighing of Analytical Portion
United States Department of Agriculture

Agricultural Marketing Service, Science & Technology

Pesticide Data Program

SOP No.: PDP-LABOP Page 2 of 42

Title: Sample Processing

Revision: 15 Replaces: 12/01/2022 Effective: 12/01/2023

5.6 Transshipment of Homogenate Subsamples

5.7 Storage of Homogenate Subsamples

5.8 Storage of Extracts

5.9 Disposal of Reserve Samples

5.10 Disposal of Extracts

4. References:

• Memorandum to State PDP Laboratories from Dr. Robert Epstein, Science Division, AMS, 

May 22, 1991

• U.S. EPA, Good Laboratory Practice Standards, 40 CFR Parts 160.47 and 160.51, August 17, 

1989 https://ntp.niehs.nih.gov/iccvam/suppdocs/feddocs/epa/epa_glp40_160.pdf

• U.S. EPA, Maintenance and calibration of equipment, 40 CFR 160.63

https://ntp.niehs.nih.gov/iccvam/suppdocs/feddocs/epa/epa_glp40_160.pdf

• U.S. EPA, Standard operating procedures, 40 CFR 160.81

https://ntp.niehs.nih.gov/iccvam/suppdocs/feddocs/epa/epa_glp40_160.pdf

• U.S. FDA, Final Preparation Procedures, Standard Operating Procedure for the Total Diet 

Study KCX-1, Appendix E, January 19, 1993

• U.S. FDA, Instructions for the Items Prepared by Contract Kitchen, Standard Operating 

Procedure for the Total Diet Study KCX-1, Appendix F, January 19, 1993

Note: References consulted in the preparation of this SOP document.

5. Sample Processing, Storage, and Disposal:

This SOP represents minimum PDP requirements and is presented as a general guideline. Each 

laboratory shall have written procedures that provide specific details concerning how the 

procedure has been implemented in that laboratory. These instructions shall include specific 

practices for minimizing cross-contamination during preparation of multiple samples (e.g., 

cleaning of equipment and utensils between samples). Both the Monitoring Programs Division 

(MPD) SOPs and the laboratories’ internal SOPs and work instructions will be used as the measure 
United States Department of Agriculture

Agricultural Marketing Service, Science & Technology

Pesticide Data Program

SOP No.: PDP-LABOP Page 3 of 42

Title: Sample Processing

Revision: 15 Replaces: 12/01/2022 Effective: 12/01/2023

of compliance in the event of an MPD laboratory review. Each sample shall be analyzed for 

identified compounds (refer to applicable commodity-specific compound list memorandum). 

5.1 Sample Receipt

Information required to be recorded in RDE/SIF

Required 

Information Detailed Instructions RDE Field SOP Section

Required/ 

Optional

Variety information If not recorded by sampler Variety Field 5.1.1 Required if 

available

Lot information If not recorded by sampler

Lot Field

(or Sample 

Comments 

Field if more 

space 

required)

5.1.1 Required if 

available

Product preparation 

prior to sample 

collection

Received as washed, 

chopped, snipped – needs 

to meet Fact Sheet 

requirements

Sample 

Comments 5.1.2 Required if relevant

Container integrity, 

adequacy, and/or 

custody seals

Container integrity

Container adequacy

Custody seals

Lab 

Comments 5.1.3 

Required if 

there are 

problems

Amount/weight 

received if different 

from required

Overweight/underweight Lab 

Comments 5.1.5 

Required if 

there are 

problems

Sample unable to be 

analyzed by lab

Specify reason sample not 

analyzed

Reason NOT 

Analyzed

5.1.4 

5.1.7 

Required if 

not analyzed

Received sample Record date sample 

received

Date/Time 

Received 5.1.1 Required 

Received sample Record person that 

received the sample Received By 5.1.1 Required 

Sample weight 

received

Record weight of sample 

received Sample Size 5.1.5 Required 
United States Department of Agriculture

Agricultural Marketing Service, Science & Technology

Pesticide Data Program

SOP No.: PDP-LABOP Page 4 of 42

Title: Sample Processing

Revision: 15 Replaces: 12/01/2022 Effective: 12/01/2023

Required 

Information Detailed Instructions RDE Field SOP Section

Required/ 

Optional

Sample weight 

homogenized

Record weight of sample 

homogenized

Analytical

Size 5.1.5 Required

Unique laboratory 

number Lab assigned number Internal Lab Identifier 5.1.11 Required

Units Record number of units

homogenized # of Units 5.1.12

Required if 

unit counting 

is specified

Note: FGIS grain sample collection is completed by FGIS and sample information is imported to 

the laboratory RDE tool. Additional information on FGIS sampling procedures is documented in 

each statement of work. Contact the PDP Sampling Team (pdp.sampling@usda.gov) for additional 

information on these procedures.

5.1.1 Sample Inspection at Receipt

5.1.1.1 Record the person who received the sample and the date received in the 

RDE sample information.

5.1.1.2 Samples shall be inspected upon arrival to verify that the sample is suitable 

for analysis based on commodity requirements (refer to current PDP Commodity 

Fact Sheet). Ensure that lot numbers on all units are the same, unless a specific 

Commodity Fact Sheet allows multiple lots to achieve required weight. Check that 

required information (variety, lot numbers, etc.) that can be determined is recorded 

in the RDE sample information (if not already recorded by sampler), and that the 

information in RDE and sample identification label match each other. This may be 

entered manually in RDE or noted on a printed Sample Information Form (SIF) and 

entered into RDE before or during reporting. 

5.1.1.3 The laboratory shall establish procedures for ensuring the sample

identification label information is retained (e.g., attaching to printed electronic SIFs 

(eSIFs), in a sample receipt logbook, etc.).
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Agricultural Marketing Service, Science & Technology

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SOP No.: PDP-LABOP Page 5 of 42

Title: Sample Processing

Revision: 15 Replaces: 12/01/2022 Effective: 12/01/2023

5.1.2 Prepared Fresh Commodity Acceptability

Prepared fresh product (e.g., snipped green beans, chopped packaged lettuce) is acceptable 

if the commodity requirements on the Commodity Fact Sheet are met. The laboratory shall 

note that the product is prepared (e.g., washed, chopped, snipped) in the “Sample 

Comments” section of the RDE sample information if it is not already noted by the sampler.

5.1.3 Sample Containers

If the sample container integrity is compromised or inadequate, document this in the “Lab 

Comment” section of the RDE sample information. The laboratory shall contact the PDP

Sampling Team (pdp.sampling@usda.gov) if there are questions as to the sample’s 

viability.

5.1.3.1 Fresh fruit and vegetable containers shall be inspected upon arrival for any 

deteriorating condition (e.g., leaking sample container) which would make the 

sample inedible or compromise sample integrity (e.g., cross contamination).

5.1.3.2 Canned commodities shall be free of large dents or punctures.

5.1.3.3 Frozen commodities shall be inspected to determine the extent of thawing 

during transit.

5.1.3.4 The plastic bags sealed by the collectors shall be opened only if absolutely 

necessary to determine the condition of the sample(s). If the sample bag is packed 

too tightly to accurately count the units (for required commodities), a rough count 

(e.g., 13-14 units) may be recorded at the time of receipt. The unit count can then 

be performed after the bag is opened prior to homogenization.

5.1.3.5 If the sample integrity is compromised (e.g., frozen samples that have 

completely thawed, bags that are not sealed, cans with dents, compromised custody 

seals, etc.), the laboratory shall contact the PDP Sampling Team

(pdp.sampling@usda.gov) to determine if analysis should be performed or if the 

sample should be re-collected.

5.1.4 Damaged Animal Tissue
United States Department of Agriculture

Agricultural Marketing Service, Science & Technology

Pesticide Data Program

SOP No.: PDP-LABOP Page 6 of 42

Title: Sample Processing

Revision: 15 Replaces: 12/01/2022 Effective: 12/01/2023

Animal tissue samples (e.g., fish), or portions thereof, received in a damaged condition 

(e.g., warm to the touch, spoiled, or leaking) shall be discarded and not analyzed. Condition 

and disposal shall be recorded on all applicable documentation. If a sample must be 

discarded, the laboratory shall immediately notify MPD. 

5.1.5 Sample Weight Acceptability Criteria

The sample is defined as the portion that the collector provides to the laboratory, usually 

between one and five pounds. The acceptable weight range is ± 20% of the target weight 

(e.g., for 5 lb. samples: 4-6 lbs). The sample weight specific to each commodity is found 

in the Commodity Fact Sheet.

Note: Determine the sample weight at the time of sample receipt and enter the weight in 

the “Sample Size” field of the RDE sample information.

5.1.5.1 Samples that weigh less than 70% of the target weight are not acceptable 

(e.g., < 3.5 lbs. for 5 lb. samples). If the sample weighs between 70% and 80% of 

the target weight, it is left to the discretion of the receiving laboratory, based on 

their best professional judgment, whether to request resampling. Alternatively, the 

laboratory may contact MPD for further guidance.

5.1.5.2 If the laboratory receives an unusually large sample (e.g., more than ten 

pounds), the laboratory may randomly select from the large sample to reach the 

targeted weight (± 20%) of product (e.g., 5 pounds for oranges) to homogenize, as 

long as units or bunches are not broken (e.g., do not halve cantaloupes or split grape 

bunches, etc.). The laboratory shall record the sample weight being homogenized 

in the “Analytical Size” field of RDE as well as any weight related issues in the 

“Lab Comments” field of the RDE sample information (e.g., received weight 

between 70 and 80% of target, laboratory randomly selected target weight due to 

large sample size received, etc.).

5.1.6 Sample Viability

5.1.6.1 For a sample to be considered viable, a minimum of 70% of the sample, by 

weight or count, should be available for analysis after any damaged/deteriorated 
United States Department of Agriculture

Agricultural Marketing Service, Science & Technology

Pesticide Data Program

SOP No.: PDP-LABOP Page 7 of 42

Title: Sample Processing

Revision: 15 Replaces: 12/01/2022 Effective: 12/01/2023

portions (e.g., wilted, mushy, moldy, etc.) are discarded (e.g., anything less than 

3.5 lbs for a 5 lb sample is not viable for analysis).

5.1.6.2 For processed commodities (e.g., cans, jars, boxes, etc.) submitted as 

multiple subsamples, the lot numbers must match.

Note: Some commodities use lot numbers that include a time stamp. For example, 

if three jars are labeled 15502B1130, 15502B1132, and 15502B1133, the lot 

number is 15502B and the last four digits are the time stamp. The time stamp 

portion can be disregarded when determining matching lot numbers. Lot number 

formats differ widely among commodities and companies. Contact MPD for 

guidance if there are questions regarding viability.

5.1.7 Documentation for Samples Not Analyzed

If sample condition upon arrival prevents analysis (e.g., entire sample mushy), the 

condition shall be documented in the “Reason NOT Analyzed” field of the RDE sample 

information. All unanalyzed samples should have the “Reason NOT Analyzed” field 

completed in RDE. 

5.1.8 Missing/Late/Unacceptable Samples or eSIFs

5.1.8.1 If a sample is not received within five working days from collection or is 

unacceptable, the laboratory shall contact the appropriate State Sampling Manager 

and the PDP Sampling Team (pdp.sampling@usda.gov) to arrange for recollection. 

Recollection should occur within the same month if possible (except December 

recollections must be within the calendar year).

5.1.8.2 If a sample arrives without a corresponding RDE SIF, the laboratory shall 

contact the appropriate State Sampling Manager within 24 hours and copy MPD at 

amsmpo.data@usda.gov.

5.1.8.3 If an eSIF contains an error that cannot be resolved with the Sampling State, 

contact MPD at amsmpo.data@usda.gov or the PDP Sampling Team at 

pdp.sampling@usda.gov.

5.1.8.4 If an RDE SIF arrives for a non-collected sample, the SIF shall be attached 
United States Department of Agriculture

Agricultural Marketing Service, Science & Technology

Pesticide Data Program

SOP No.: PDP-LABOP Page 8 of 42

Title: Sample Processing

Revision: 15 Replaces: 12/01/2022 Effective: 12/01/2023

to a group/set and submitted in RDE by the laboratory. The non-collected sample 

can be attached to a group that contains routine analyzed samples or to a group that 

contains just non-collected samples. This allows MPD to track the number of 

missing samples and the reasons why the samples were not collected.

5.1.9 Unresolved Sampling Issues

The receiving laboratory shall notify the PDP Sampling Team (pdp.sampling@usda.gov) 

of any continuing unresolved sampling issues monthly.

5.1.10 Paper SIFs

If a paper SIF is received, the laboratory shall scan and email to MPD

(amsmpo.data@usda.gov) within 24 hours. Grain samples collected by FGIS are exempt 

from this SIF requirement. 

5.1.11 Unique Laboratory Sample ID

Each sample shall be assigned a unique laboratory identification number. The identification 

number shall be recorded on or affixed to samples and sample aliquots in a manner to 

ensure its legibility during handling and storage. This number shall also be recorded on the 

accompanying paperwork and in the “Internal Lab ID” field in the RDE sample 

information.

5.1.12 Unit Counting

For all large non-clustered commodities (e.g., apples, cantaloupe, onions, pears, sweet 

potatoes, etc.) the counting of homogenized units (i.e., pieces of individual produce) is 

required for EPA to perform some of their risk assessment calculations. For any given 

commodity, a determination of whether units shall be counted is stipulated in Section 5.3

of this SOP. Units shall be examined prior to homogenization and damaged units discarded. 

If more than one-third of the edible portion is damaged, discard the entire unit, then count 

the remaining units. Record the count of homogenized units in the “# of Units” field in the 

RDE sample information. Refer to Section 5.1.3.4 if the sample bag is so tightly packed 

that accurate unit counting cannot be performed.

5.1.13 Sample Receipt Log
United States Department of Agriculture

Agricultural Marketing Service, Science & Technology

Pesticide Data Program

SOP No.: PDP-LABOP Page 9 of 42

Title: Sample Processing

Revision: 15 Replaces: 12/01/2022 Effective: 12/01/2023

Each laboratory shall maintain a log of samples received. Suggested methods are either in 

a bound notebook with ink or a computer log as long as the electronic storage of data 

follows acceptable practices. Refer to SOP PDP-DATA. Minimum information recorded 

includes sample numbers, date and time received (unless documented on the SIF), and who 

received the sample. Other information may include commodity type, reference to 

analytical method, results, and date when results were reported.

5.2 Sample Storage Prior to Homogenization

5.2.1 All refrigerators and freezers used for PDP samples shall have controlled access.

Each laboratory shall have a system in place to monitor and document temperatures and 

sample traffic. The temperature checks shall be made each working day, or the laboratory 

may use automatic temperature recording devices. Checks shall be recorded. 

5.2.2 Samples shall be stored in refrigerators and freezers separate from standards.

5.2.3 Fresh fruits and vegetables still sealed in bags shall be refrigerated for a period not 

to exceed 72 hours, or 120 hours, depending on whether it is perishable, from the time of 

arrival until the sample is homogenized. Section 5.3 of this SOP lists the maximum holding 

time prior to homogenization for each PDP commodity.

5.2.4 Processed commodities normally stored by consumers at room temperature (e.g., 

in cans, jars, shelf-stable boxes, etc.) shall be stored in a clean, dry area at room temperature 

(approximately 22 °C) or lower for a period not to exceed 120 hours from the time of arrival 

until the sample is homogenized. Processed commodities that require refrigeration (e.g. 

dairy, refrigerated juices, eggs, etc.), may not exceed 72 hours refrigeration from the arrival 

time until the sample is homogenized.

5.2.5 Frozen commodities that have not thawed in transit (still cold to the touch) shall be 

held in the freezer at approximately 0 °C or lower until the sample is homogenized.

5.2.6 Frozen commodities that thawed in transit (not cold to the touch) shall be 

refrigerated and the PDP Sampling Team shall be contacted at PDP.sampling@udsa.gov

to determine sample viability. If the sample is determined to be viable, the sample should 

be homogenized within 24 hours (from the time of arrival); however, refrigeration of the 

thawed commodity for a period not to exceed 72 hours (from the time of arrival) may be
United States Department of Agriculture

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Pesticide Data Program

SOP No.: PDP-LABOP Page 10 of 42

Title: Sample Processing

Revision: 15 Replaces: 12/01/2022 Effective: 12/01/2023

acceptable.

5.2.7 Grain commodities shall be refrigerated for a period not to exceed 120 hours from 

the arrival time until the sample is homogenized. 

5.3 Preparation and Homogenization of Fresh Produce, Animal Tissue, Nuts, and 

Grains

For all commodities, the entire sample shall be prepared for homogenization according to the 

commodity-specific instructions in this section. If the entire sample does not fit into the 

homogenizer/chopper at one time, then the sample may be homogenized in portions. All portions 

shall be mixed together in a clean container to ensure an evenly mixed sample.

If the laboratory receives a sample that weighs significantly more than the targeted weight (e.g., 

10 pounds when target weight is 5 pounds), follow the instructions in Sections 5.1.5.2 and 5.1.6 

of this SOP. 

Commodity PDP Code

SOP Preparation 

and 

Homogenization 

Section

Almonds AL 5.3.1

Apples 

Fruit AP 5.3.3 

Juice AJ 5.4.3

(Juices/Concentrates)

Sauce AC

5.4.5 (Other 

Processed, Semiprocessed, Packaged)

Asparagus AS 5.3.4 

Avocados AV 5.3.5

Baby foods 

Applesauce IA

5.4.5 (Other 

Processed, Semiprocessed, Packaged)

Carrots IC

Green Beans IG

Peaches IH

Pears IP
United States Department of Agriculture

Agricultural Marketing Service, Science & Technology

Pesticide Data Program

SOP No.: PDP-LABOP Page 11 of 42

Title: Sample Processing

Revision: 15 Replaces: 12/01/2022 Effective: 12/01/2023

Commodity PDP Code

SOP Preparation 

and 

Homogenization 

Section

Peas IE

Sweet potatoes IS

Bananas BN 5.3.6 

Basil BS 5.3.16 

Barley BY 5.3.20 (Grains)

Beans

Canned

Black

BC 5.4.1 (Canned 

Commodities)

Kidney

Pinto

Garbanzo 

(Chickpea) ZB

Dried

Garbanzo, 

dried 

(Chickpea)

ZD 5.4.5.6 

Green GB 5.3.7 

Beets, canned BT 5.4.1 (Canned 

Commodities)

Blackberry

Fresh BK 5.3.8 

Frozen KZ* 5.4.2 (Frozen 

Commodities)

Blueberry

Fresh BB 5.3.8 

Frozen BZ* 5.4.2 (Frozen 

Commodities)

Broccoli BR 5.3.9 

Butter BU

5.4.5 (Other 

Processed, Semiprocessed, Packaged)

Cabbage CG 5.3.10 

Cantaloupe CN 5.3.11 
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SOP No.: PDP-LABOP Page 12 of 42

Title: Sample Processing

Revision: 15 Replaces: 12/01/2022 Effective: 12/01/2023

Commodity PDP Code

SOP Preparation 

and 

Homogenization 

Section

Carrots CR 5.3.12 

Cauliflower CF 5.3.13

Celery CE 5.3.14 

Cherries, Sweet

Fresh CH 5.3.15 

Frozen CZ* 5.4.2 (Frozen 

Commodities)

Cilantro CL 5.3.16 

Corn

Grain CO 5.3.20 (Grains)

Sweet, Fresh CB 5.3.17

Sweet, Frozen CS 5.4.2 (Frozen 

Commodities)

Sweet, Canned CD 5.4.1 (Canned 

Commodities)

Syrup CY

5.4.5 (Other 

Processed, Semiprocessed, Packaged)

Cranberry

Fresh CA 5.3.8 

Frozen AZ* 5.4.2 (Frozen 

Commodities)

Canned RC 5.4.1 (Canned 

Commodities)

Cream, heavy CM

5.4.5 (Other 

Processed, Semiprocessed, Packaged)

Cucumbers CU 5.3.18 

Egg EG 5.4.5.5

Eggplant EP 5.3.19 

Fish Catfish FC 5.3.2 (Animal 
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SOP No.: PDP-LABOP Page 13 of 42

Title: Sample Processing

Revision: 15 Replaces: 12/01/2022 Effective: 12/01/2023

Commodity PDP Code

SOP Preparation 

and 

Homogenization 

Section

Salmon FS Tissue-Fish)

Grapefruit GF 5.3.31 

Grapes

Fruit GR 5.3.21

Juice GJ 5.4.3 

(Juices/Concentrates)

Greens

Collard GL

Kale GK 5.3.22

Mustard MG

Honey HY

5.4.5 (Other 

Processed, Semiprocessed, Packaged)

Honey Dew Melon HD 5.3.23

Infant formula Dairy-based DF5.4.5.4 Soy-based YF

Kiwi KW 5.3.24 

Lettuce

Head LH/LT 5.3.25

Leaf LL/LT 5.3.26 

Bagged LB

5.4.5 (Other 

Processed, Semiprocessed, Packaged)

Mangoes MA 5.3.27 

Milk, whole MK

5.4.5 (Other 

Processed, Semiprocessed, Packaged)

Mushrooms MU 5.3.28 

Nectarines NE 5.3.33
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SOP No.: PDP-LABOP Page 14 of 42

Title: Sample Processing

Revision: 15 Replaces: 12/01/2022 Effective: 12/01/2023

Commodity PDP Code

SOP Preparation 

and 

Homogenization 

Section

Oats OA 5.3.20 (Grains)

Olives Canned OL 5.4.1 (Canned 

Commodities)

Onions Bulb ON 5.3.29 

Green GO 5.3.30

Orange

Fruit OG 5.3.31 

Juice OJ 5.4.3 

(Juices/Concentrates)

Papaya YA 5.3.32 

Peaches

Fruit PC 5.3.33 

Canned CC 5.4.1 (Canned 

Commodities)

Frozen PZ* 5.4.2 (Frozen 

Commodities)

Peanut Butter PB

5.4.5 (Other 

Processed, Semiprocessed, Packaged)

Pears

Fruit PE 5.3.34 

Juice PJ 5.4.3 

(Juices/Concentrates)

Canned CP 5.4.1 (Canned 

Commodities)

Peas

Green, Fresh SE 5.3.35

Green, Frozen PS 5.4.2 (Frozen 

Commodities)
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SOP No.: PDP-LABOP Page 15 of 42

Title: Sample Processing

Revision: 15 Replaces: 12/01/2022 Effective: 12/01/2023

Commodity PDP Code

SOP Preparation 

and 

Homogenization 

Section

Green, Canned SD 5.4.1 (Canned 

Commodities)

Snap SN 5.3.36 

Peppers Bell, Sweet PP 5.3.37

Hot HP 5.3.38 

Pineapples

Fresh PN 5.3.39 

Canned NC 5.4.1 (Canned 

Commodities)

Plums

Fresh PU 5.3.40

Dried PD 5.4.4 (Dried Fruits)

Potatoes

Fresh PO 5.3.41 

Frozen PZ* 5.4.2 (Frozen 

Commodities)

Sweet SW 5.3.42 

Pumpkin Canned PK 5.4.1 (Canned 

Commodities)

Radish RD 5.3.43 

Raisins RA 5.4.4.1 

Raspberries

Fresh RS 5.3.8 

Frozen RZ* 5.4.2 (Frozen 

Commodities)

Rice RI 5.3.20 (Grains)

Soybeans, Grain SY 5.3.20 (Grains)

Spinach

Leafy SP 5.3.44 

Canned SC 5.4.1 (Canned 

Commodities)
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SOP No.: PDP-LABOP Page 16 of 42

Title: Sample Processing

Revision: 15 Replaces: 12/01/2022 Effective: 12/01/2023

Commodity PDP Code

SOP Preparation 

and 

Homogenization 

Section

Frozen SF 5.4.2 (Frozen 

Commodities)

Squash

Summer SS 5.3.45 

Winter WS 5.3.46

Winter, frozen WZ 5.4.2 (Frozen 

Commodities)

Strawberries

Fresh ST 5.3.47

Frozen SZ* 5.4.2 (Frozen 

Commodities)

Tangerines TA 5.3.31 

Tomatillo TT _5.3.48_

Tomatoes

Cherry CT 5.3.49

Fresh TO 5.3.50

Canned TC 5.4.1 (Canned 

Commodities)

Paste TP

5.4.5 (Other 

Processed, Semiprocessed, Packaged)

Watermelon WM _5.3.51_

Wheat

Grain WH _5.3.20 (Grains)

Flour WF

5.4.5 (Other 

Processed, Semiprocessed, Packaged)

* For USDA use only

5.3.1 Almonds

Grind the entire sample using an appropriate device (e.g., centrifugal mill, Wiley mill, etc.) 

just until a visually homogeneous mixture is attained. Unit counting is not required.
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Title: Sample Processing

Revision: 15 Replaces: 12/01/2022 Effective: 12/01/2023

Refrigeration may not exceed 120 hours from the arrival time until the sample is 

homogenized.

5.3.2 Animal Tissue-Fish

Remove the skin and bones and mechanically homogenize the entire submitted tissue 

sample until a visually homogeneous mixture is attained. The laboratory shall use its 

discretion in the utilization of dry ice during the homogenization procedure. Unit counting 

is not required.

5.3.3 Apples

Wash each apple under cold running tap water for approximately 15-20 seconds to ensure

that all surfaces of the apple have been rinsed. Allow to drain for at least 2 minutes. Do not 

peel. Remove the stem, if present. With a commercially available apple corer, remove core. 

Alternatively, use a clean, dry knife to cut each apple in half or quarters and remove the 

core portion. Mechanically chop just until a visually homogeneous mixture is attained. Unit 

counting is required. Refrigeration may not exceed 120 hours from the arrival time until 

the sample is homogenized.

5.3.4 Asparagus 

Remove an inch or two of the woody stems, if inedible. Wash asparagus spears under cold 

running tap water for approximately 15-20 seconds to ensure that all surfaces have been 

rinsed. Allow to drain for at least 2 minutes. Mechanically chop just until a visually 

homogeneous mixture is attained. Unit counting is not required. Refrigeration may not 

exceed 72 hours from the arrival time until the sample is homogenized.

5.3.5 Avocados

If necessary, avocado samples may be stored in a secure location at room temperature for 

72 hours for ripening purposes. Wash avocados under cold running tap water for 

approximately 15-20 seconds to ensure that all surfaces have been rinsed. Allow to drain 

for at least 2 minutes. Using a clean, dry knife, cut the avocado around the pit (i.e., without 

cutting through the pit). Remove the pit and skin, being careful to keep as much of the meat 

as possible. Mechanically chop just until a visually homogeneous mixture is attained. Unit 

counting is required. If avocado samples are too unripe for proper preparation, additional 
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hours at room temperature to ripen are permissible. However, the samples should be 

checked daily and processed as soon as they are ripe. Samples can be stored in paper bags 

to assist with ripening.

5.3.6 Bananas

If necessary, banana samples may be stored in a secure location at room temperature for 

up to 72 hours for ripening purposes. To accelerate ripening, the bananas can be stored in 

a paper bag. Peel each fruit. Mechanically chop just until a visually homogeneous mixture 

is attained. Unit counting is required. Refrigeration may not exceed 72 hours for ripe 

bananas and 120 hours for green bananas from the arrival time until the sample is 

homogenized.

5.3.7 Beans, Green

Wash fresh beans under cold running tap water for approximately 15-20 seconds to ensure

that all surfaces have been rinsed. Allow to drain for at least 2 minutes. Do not peel. Using 

a clean, dry knife, remove any stems that are present. Mechanically chop just until a 

visually homogeneous mixture is attained. Unit counting is not required. Refrigeration may 

not exceed 72 hours from the arrival time until the sample is homogenized.

5.3.8 Blueberries/Cranberries/Raspberries/Blackberries

Wash blueberries/cranberries/raspberries/blackberries by the handful or by using a 

colander under cold running tap water for approximately 15-20 seconds to ensure that all 

surfaces are rinsed. Allow to drain for at least 2 minutes. Mechanically chop just until a 

visually homogeneous mixture is attained. Unit counting is not required. Refrigeration may 

not exceed 72 hours from the arrival time until the sample is homogenized.

5.3.9 Broccoli

Visually examine and discard any damaged portion or wilted florets. Do not discard leaves 

unless they are wilted. Trim away inedible portions of stems. If the stem is less than 3 

inches, do not trim. If the stem is longer than 3 inches, thinly slice away the tough outer 

layer on the stalk. Wash the sample under cold running tap water for approximately 15-20 

seconds to ensure that all surfaces have been rinsed. Allow to drain for at least 2 minutes.

Mechanically chop just until a visually homogeneous mixture is attained. Unit counting is 
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not required. Refrigeration may not exceed 72 hours from the arrival time until the sample 

is homogenized.

5.3.10 Cabbage

Visually examine the head, remove wrapper, damaged or wilted leaves, and the core. Rinse 

the head under cold running tap water for approximately 15-20 seconds. Turn the head top 

side down. Allow to drain for at least 2 minutes. Mechanically chop just until a visually 

homogeneous mixture is attained. Unit counting is required. Refrigeration may not exceed 

120 hours from the arrival time until the sample is homogenized.

5.3.11 Cantaloupes

Using a clean, dry knife, cut each cantaloupe in half and remove seeds and rind. Halves 

may be further divided at this point to facilitate removal of the rind. Mechanically chop 

just until a visually homogeneous mixture is attained. Unit counting is required.

Refrigeration may not exceed 72 hours from the arrival time until the sample is 

homogenized.

5.3.12 Carrots

If carrots have any visible dirt, hold each carrot under cold running tap water and gently 

scrub the entire surface with a clean vegetable brush to remove any loose soil and grit.

Rinse each scrubbed carrot under cold running tap water for approximately 15-20 seconds 

to ensure that all surfaces of the carrot have been rinsed. Allow to drain for at least 2 

minutes. With a clean, dry knife, remove stem cap portion from each carrot. Mechanically 

chop just until a visually homogeneous mixture is attained. Unit counting is required.

Refrigeration may not exceed 120 hours from the arrival time until the sample is 

homogenized.

5.3.13 Cauliflower

Visually examine the head and remove wrapper leaves and any damaged portions. Rinse 

the head under cold running tap water for approximately 15-20 seconds. Turn the head top 

side up. Allow to drain for at least 2 minutes. Mechanically chop just until a visually 

homogenous mixture is attained. Unit counting is required. Refrigeration may not exceed 
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72 hours from the arrival time until the sample is homogenized.

5.3.14 Celery

Using a clean, dry knife, remove the inedible portion of the stalk (i.e., the woody part at 

the base of the stalk) to allow the stems to separate. Do not remove the leaves unless 

discolored or damaged. Wash the stems under cold running water for approximately 15-20 

seconds to ensure that all surfaces have been rinsed and that all extraneous matter (e.g., 

soil) is removed. Allow to drain for at least 2 minutes. Mechanically chop just until a 

visually homogeneous mixture is attained. Unit counting is not required. Refrigeration may 

not exceed 120 hours from the arrival time until the sample is homogenized.

5.3.15 Cherries, Sweet

Remove the stem from each cherry. Wash cherries under cold running tap water for 

approximately 15-20 seconds to ensure that all surfaces are rinsed. Allow to drain for at 

least 2 minutes. Remove the pit, being careful to remove as little of the meat as possible.

A commercial cherry pitter is recommended. Mechanically chop just until a visually 

homogeneous mixture is attained. Unit counting is not required. Refrigeration may not 

exceed 72 hours from the arrival time until the sample is homogenized.

5.3.16 Cilantro\Basil

Using a clean, dry knife, trim the ends. Remove the discolored or damaged leaves. Wash 

the stems with the leaves under cold running water for approximately 15-20 seconds to 

ensure that all surfaces have been rinsed and that all extraneous matter (e.g., soil) is 

removed. Allow to drain for at least 2 minutes. Mechanically chop just until a visually 

homogeneous mixture is attained. Unit counting is not required. Refrigeration may not 

exceed 72 hours from the arrival time until the sample is homogenized.

5.3.17 Corn

Remove husk and silk from each ear. Wash each ear under cold running tap water for 

approximately 15-20 seconds to ensure that all surfaces are rinsed. Allow to drain for at 

least 2 minutes. Using a clean dry knife or other appropriate utensil, remove the kernels 

from cob. Mechanically chop just until a visually homogeneous mixture is attained. Unit 

counting is required. Refrigeration may not exceed 72 hours from the arrival time until the 
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sample is homogenized.

5.3.18 Cucumbers

Wash each cucumber under cold running tap water for approximately 15-20 seconds to 

ensure that all surfaces of the cucumber are rinsed. Allow to drain for at least 2 minutes.

Cucumbers may be halved or quartered at this point to facilitate homogenization.

Mechanically chop just until a visually homogeneous mixture is attained. Unit counting is 

required. Refrigeration may not exceed 72 hours from the arrival time until the sample is 

homogenized.

5.3.19 Eggplant

Wash each eggplant under cold running tap water for approximately 15-20 seconds to 

ensure that all surfaces are rinsed. Allow to drain for at least 2 minutes. Using a clean, dry 

knife, remove the end pieces. Mechanically chop just until a visually homogenous mixture 

is attained. Unit counting is required. Refrigeration may not exceed 72 hours from the 

arrival time until the sample is homogenized.

5.3.20 Grains

The grain sample should be inspected prior to processing and large debris (i.e., stones, 

sticks, large pieces of dirt, etc.) should be removed. The entire grain sample received from 

the Federal Grain Inspection Service (i.e., corn, wheat, soybean, barley) is to be 

homogenized, while for other grains (i.e., oats, rice) the entire sample is poured into a 

container and mixed thoroughly to obtain a 500 gram sub-sample for homogenization. 

Grind the sample using an appropriate device (e.g., Falling 3300 laboratory mill, Jacobsen 

grinder, UDY grinder). Tumble the resulting powder homogenate to obtain a homogeneous 

mixture. Unit counting is not required. Refrigeration may not exceed 120 hours from the 

arrival time until the sample is homogenized.

5.3.21 Grapes

Wash each sample under cold running tap water for approximately 15-20 seconds to ensure

that all surfaces have been rinsed. Allow to drain for at least 2 minutes. Remove all stems 

and extraneous matter. Mechanically chop just until a visually homogeneous mixture is 

attained. Unit counting is not required. Refrigeration may not exceed 72 hours from the 
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arrival time until the sample is homogenized.

5.3.22 Greens

Visually examine the sample and remove only the damaged or wilted leaves and any woody 

stems. Wash remaining sample under cold running tap water for approximately 15-20 

seconds to ensure that all surfaces have been rinsed. Allow to drain for at least 2 minutes. 

Note: Bagged pre-washed greens do not require washing by the laboratory.

Mechanically chop just until a visually homogeneous mixture is attained. Unit counting is 

not required. Refrigeration may not exceed 72 hours from the arrival time until the sample 

is homogenized.

5.3.23 Honeydew Melons

Using a clean, dry knife, cut each melon in half and remove seeds and rind. Halves may be 

further divided at this point to facilitate removal of the rind. Mechanically chop just until 

a visually homogeneous mixture is attained. Unit counting is required. Refrigeration may 

not exceed 72 hours from the arrival time until the sample is homogenized.

5.3.24 Kiwi

Wash each kiwi under cold running tap water for approximately 15-20 seconds to ensure

that all surfaces are rinsed. Allow to drain for at least 2 minutes. Do not peel. Mechanically 

chop just until a visually homogeneous mixture is attained. Unit counting is required.

Refrigeration may not exceed 72 hours from the arrival time until the sample is 

homogenized.

5.3.25 Lettuce, Head

Visually examine the head and remove wrapper and damaged or wilted leaves. Rinse the 

head under cold running tap water for approximately 15-20 seconds. Turn the head top side 

down. Allow to drain for at least 2 minutes. Mechanically chop just until a visually 

homogeneous mixture is attained. Unit counting is required. Refrigeration may not exceed 

72 hours from the arrival time until the sample is homogenized.
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5.3.26 Lettuce, Leaf

Visually examine the sample and remove only the damaged or wilted leaves and any woody 

stems. Wash remaining sample under cold running tap water for approximately 15-20 

seconds to ensure that all surfaces have been rinsed. Allow to drain for at least 2 minutes.

Mechanically chop just until a visually homogeneous mixture is attained. Unit counting is 

required if discrete bunches are received. Unit counting is not required if loose leaves are 

received. Refrigeration may not exceed 72 hours from the arrival time until the sample is 

homogenized.

5.3.27 Mangoes

Mango skin contains small amounts of urushiol (the same chemical as in poison ivy) and 

may cause an allergic reaction or induced contact dermatitis. People with sensitive skin 

should handle mangoes with gloves. Wash each mango under cold running tap water for 

approximately 15-20 seconds to ensure that all surfaces of the fruit are rinsed. Allow to 

drain for at least 2 minutes. Do not peel. Remove stem if present. Using a clean, dry knife, 

cut the mango around the pit (i.e., without cutting through the pit). Remove the pit, being 

careful to remove as little of the meat as possible. Mechanically chop just until a visually 

homogeneous mixture is attained. Unit counting is required. Refrigeration may not exceed 

72 hours for ripe mangoes and 120 hours for green mangoes from the arrival time until the 

sample is homogenized.

5.3.28 Mushrooms

Wash mushrooms under cold running tap water for approximately 15-20 seconds to ensure

that all surfaces are rinsed. Allow to drain for at least 2 minutes. Using a clean, dry knife, 

slightly trim end pieces to remove any inedible/woody portions. Mechanically chop just 

until a visually homogeneous mixture is attained. Unit counting is not required.

Refrigeration may not exceed 72 hours from the arrival time until the sample is 

homogenized.

5.3.29 Onions, Bulb

Using a clean knife, remove onion top, outer layer, first white layer and membrane, and 

any other inedible portions. Remove root portion last to minimize fumes. Preparation 

procedures may be performed with onions immersed in cold tap water, with total 
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immersion time for each unit not to exceed 10 minutes. Allow onions to drain at least 2 

minutes. Mechanically chop just until a visually homogeneous mixture is attained. Unit 

counting is required. Refrigeration may not exceed 120 hours from the arrival time until 

the sample is homogenized.

5.3.30 Onions, Green

Wash green onions under cold running tap water for approximately 15-20 seconds to ensure

that all surfaces have been rinsed. Allow to drain for at least 2 minutes. Using a clean, dry 

knife, trim the bulb end of any roots/inedible material and trim the tops if damaged or 

wilted. Mechanically chop just until a visually homogeneous mixture is attained. Unit 

counting is not required. Refrigeration may not exceed 72 hours from the arrival time until 

the sample is homogenized.

5.3.31 Oranges/Tangerines/Grapefruit

Peel each fruit and remove any excess white membrane. Mechanically chop just until a 

visually homogeneous mixture is attained. Unit counting is required. Refrigeration may not 

exceed 120 hours from the arrival time until the sample is homogenized.

5.3.32 Papaya

If necessary, papaya samples may be stored in a secure location at room temperature for 

up to 72 hours for ripening purposes. Wash each papaya under cold running tap water for 

approximately 15-20 seconds to ensure that all surfaces of the fruit are rinsed. Allow to 

drain for at least 2 minutes. Cut in half. Scoop out and discard seeds. Scoop out flesh for 

homogenization. Mechanically chop just until a visually homogeneous mixture is attained.

Unit counting is required. Refrigeration may not exceed 72 hours for ripe papayas and 120 

hours for green papayas from the arrival time until the sample is homogenized.

5.3.33 Peaches/Nectarines

Wash each peach/nectarine under cold running tap water for approximately 15-20 seconds 

to ensure that all surfaces of the peach/nectarine are rinsed. Allow to drain for at least 2 

minutes. Do not peel. Remove stem and leaves if present. Using a clean, dry knife, cut the 

peach around the pit (i.e., without cutting through the pit). Remove the pit, being careful 
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to remove as little of the meat as possible. Mechanically chop just until a visually 

homogeneous mixture is attained. Unit counting is required. Refrigeration may not exceed 

72 hours from the arrival time until the sample is homogenized.

5.3.34 Pears

Wash each pear under cold running tap water for approximately 15-20 seconds to ensure

that all surfaces of the pear have been rinsed. Allow to drain for at least 2 minutes. Do not 

peel. Remove stem, if present. Using a clean, dry knife, cut each pear in half or quarters 

and remove the core portion. Mechanically chop just until a visually homogeneous mixture 

is attained. Unit counting is required. Refrigeration may not exceed 72 hours from the 

arrival time until the sample is homogenized.

5.3.35 Peas, Green

For each sample, shell enough peas to comprise at least one cup. Discard pods. Rinse peas 

under cold running tap water for approximately 15-20 seconds to ensure that all surfaces 

have been rinsed. Allow to drain for at least 2 minutes. Mechanically chop just until a 

visually homogeneous mixture is attained. Unit counting is not required. Refrigeration may 

not exceed 72 hours from the arrival time until the sample is homogenized.

5.3.36 Peas, Snap

For each sample, rinse snap peas under cold running tap water for approximately 15-20 

seconds to ensure that all surfaces have been rinsed. Allow to drain for at least 2 minutes. 

Remove inedible portion(s).

Note: Bagged pre-washed (including ready-to-eat and steam in bag) snap peas do not 

require washing and may be processed as-is by the laboratory.

Mechanically chop just until a visually homogeneous mixture is attained. Unit counting is 

not required. Refrigeration may not exceed 72 hours from the arrival time until the sample 

is homogenized.

5.3.37 Peppers, Bell Sweet

Wash each pepper under cold running tap water for approximately 15-20 seconds to ensure
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that all surfaces are rinsed. Allow to drain for at least 2 minutes. Using a clean, dry knife, 

remove stem, core, and seeds. Mechanically chop just until a visually homogeneous 

mixture is attained. Unit counting is required. Refrigeration may not exceed 72 hours from 

the arrival time until the sample is homogenized.

5.3.38 Peppers, Hot

Wash each sample under cold running tap water for approximately 15-20 seconds to ensure

that all surfaces are rinsed. Allow to drain for at least 2 minutes. Using a clean, dry knife, 

remove stem. Mechanically chop just until a visually homogeneous mixture is attained.

Unit counting is not required. Refrigeration may not exceed 72 hours from the arrival time 

until the sample is homogenized.

5.3.39 Pineapples

Wash each pineapple under cold running tap water for approximately 15-20 seconds to 

ensure that all surfaces of the fruit have been rinsed. Allow to drain for at least 2 minutes.

Remove the top of each pineapple. Using a clean, dry knife, cut in half and remove core 

and shell. Mechanically chop just until a visually homogeneous mixture is attained. Unit 

counting is required. Refrigeration may not exceed 72 hours from the arrival time until the 

sample is homogenized.

5.3.40 Plums

Wash each plum under cold running tap water for approximately 15-20 seconds to ensure

that all surfaces are rinsed. Allow to drain for at least 2 minutes. Do not peel. Remove stem 

and leaves if present. Using a clean, dry knife, cut the plum around the pit (i.e., without 

cutting through the pit). Remove the pit, being careful to remove as little of the meat as 

possible. Mechanically chop just until a visually homogeneous mixture is attained. Unit 

counting is required. Refrigeration may not exceed 72 hours from the arrival time until the 

sample is homogenized.

5.3.41 Potatoes

Hold each potato under cold running tap water and gently scrub the entire surface with a 

clean vegetable brush to remove any loose soil and grit. Rinse each scrubbed potato under 

cold running tap water for approximately 15-20 seconds to ensure that all surfaces of the 
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potato have been rinsed and allow to drain for at least 2 minutes. Mechanically chop just 

until a visually homogeneous mixture is attained. Unit counting is required. Refrigeration 

may not exceed 120 hours from the arrival time until the sample is homogenized.

Due to the widespread use of chlorpropham in potatoes combined with the high 

concentrations present and the chemical nature of the compound, care must be taken to 

prevent laboratory cross-contamination. If multiple commodities are being processed, the 

potatoes should be held for last. All equipment, including cutting boards, knives, bowls, 

etc., should be solvent washed after potato contact. The use of separate grinding bowls is 

recommended.

5.3.42 Potatoes, Sweet

Hold each sweet potato under cold running tap water and gently scrub the entire surface 

with a clean vegetable brush to remove any loose soil and grit (remove any woody stems 

if present). Rinse each scrubbed sweet potato under cold running tap water for 

approximately 15-20 seconds to ensure that all surfaces have been rinsed. Allow to drain 

for at least 2 minutes. Mechanically chop just until a visually homogeneous mixture is 

attained. Unit counting is required. Refrigeration may not exceed 120 hours from the arrival 

time until the sample is homogenized.

5.3.43 Radish

Hold each radish under cold running tap water and remove any loose soil and grit (discard 

the leaf portion). Rinse each radish under cold running tap water for approximately 15-20 

seconds to ensure that all surfaces are rinsed. Allow to drain for at least 2 minutes. 

Note: Bagged pre-washed radishes do not require washing by the laboratory. 

If there are tops or roots present, remove with a clean, dry knife. Mechanically chop just 

until a visually homogeneous mixture is attained. Unit counting is not required. 

Refrigeration may not exceed 120 hours from the arrival time until the sample is 

homogenized.

5.3.44 Spinach

Visually examine the sample and remove only the damaged or wilted leaves and any woody 
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stems. Wash remaining sample under cold running tap water for approximately 15-20 

seconds to ensure that all surfaces have been rinsed. Allow to drain for at least 2 minutes.

Note: Bagged pre-washed spinach does not require washing by the laboratory.

Mechanically chop just until a visually homogeneous mixture is attained. Unit counting is 

not required. Refrigeration may not exceed 72 hours from the arrival time until the sample 

is homogenized.

5.3.45 Squash, Summer

Wash each squash under cold running tap water for approximately 15-20 seconds to ensure

that all surfaces are rinsed. Allow to drain for at least 2 minutes. Using a clean, dry knife, 

remove end pieces. Mechanically chop just until a visually homogeneous mixture is 

attained. Unit counting is required. Refrigeration may not exceed 72 hours from the arrival 

time until the sample is homogenized.

5.3.46 Squash, Winter

Wash each squash under cold running tap water for approximately 15-20 seconds to ensure

that all surfaces are rinsed. Allow to drain for at least 2 minutes. Using a clean, dry knife, 

remove stem and/or end pieces. Mechanically chop just until a visually homogeneous 

mixture is attained. Unit counting is required. Refrigeration may not exceed 120 hours from 

the arrival time until the sample is homogenized.

5.3.47 Strawberries

Wash strawberries by the handful or by using a colander under cold running tap water for 

approximately 15-20 seconds to ensure that all surfaces are rinsed. Allow to drain for at 

least 2 minutes. Remove stems and leaves if present. Mechanically chop just until a visually 

homogeneous mixture is attained. Unit counting is not required. Refrigeration may not 

exceed 72 hours from the arrival time until the sample is homogenized.

5.3.48 Tomatillos

Remove the husk, if present. After the husks are removed, wash tomatillos under cold 

running tap water for approximately 15-20 seconds to ensure that all surfaces of the 
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tomatillos are rinsed, and the sticky residue is removed. Allow to drain for at least 2 

minutes. Do not peel. Using a clean, dry knife, cut the tomatillo around the stem area. 

Remove any stem, being careful to remove as little of the meat as possible. The tomatillos 

may be quartered prior to homogenization. Mechanically chop just until a visually 

homogeneous mixture is attained. Unit counting is required. Refrigeration may not exceed 

72 hours from the arrival time until the sample is homogenized.

5.3.49 Tomatoes, Cherry

Wash tomatoes under cold running tap water for approximately 15-20 seconds to ensure

that all surfaces of the tomatoes are rinsed. Allow to drain for at least 2 minutes. Do not 

peel. Remove any present stems. Unit counting is not required. Refrigeration may not 

exceed 72 hours from the arrival time until the sample is homogenized.

5.3.50 Tomatoes, Fresh

Wash each tomato under cold running tap water for approximately 15-20 seconds to ensure

that all surfaces of the tomato are rinsed. Allow to drain for at least 2 minutes. Do not peel.

Using a clean, dry knife, cut the tomato around the stem area. Remove any stem, being 

careful to remove as little of the meat as possible. The tomatoes may be quartered prior to 

homogenization. Mechanically chop just until a visually homogeneous mixture is attained.

Unit counting is required. Refrigeration may not exceed 72 hours from the arrival time 

until the sample is homogenized.

5.3.51 Watermelon

Wash each melon under cold running tap water for approximately 15-20 seconds to ensure

that all surfaces are rinsed. Allow to drain for at least 2 minutes. Using a clean, dry knife, 

cut each watermelon into quarters, and remove the rind. For large watermelons, take 

alternate quarters of each fruit and mechanically chop just until a visually homogeneous 

mixture is attained. For small watermelons, take the entire sample and mechanically chop 

just until a visually homogeneous mixture is attained. If only pre-cut is available, do not 

rinse watermelon; remove the rind and mechanically chop just until a visually 

homogeneous mixture is attained. Unit counting is required. Refrigeration may not exceed 

72 hours from the arrival time until the sample is homogenized.

5.4 Preparation and Homogenization of Processed Commodities
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The sample is defined as the portion that the collector sends to the laboratory, usually between one 

and five pounds. For all commodities except dried fruits, the entire sample shall be homogenized.

For dried fruits, the entire sample is mixed to obtain a representative analytical portion prior to 

hydration and analysis. If the entire sample does not fit into the homogenizer/chopper at one time, 

then the sample may be homogenized in portions. All portions shall be mixed together in a clean 

container to ensure an evenly mixed sample.

5.4.1 Canned Commodities

Rinse the lid under cold running tap water for 5 to 10 seconds. Dry the lid with a paper 

towel. Open each can and pour the entire contents of each can including the liquid into a 

blender/homogenizer. Blend just until a visually homogeneous mixture is attained. Refer 

to section 5.2 for sample hold time prior to homogenization.

5.4.2 Frozen Commodities

The samples may be chopped while frozen, or to prevent damage to the 

chopper/homogenizer blades, the sample may be thawed in a refrigerator. A room 

temperature water bath may be used only if the sample is enclosed in watertight packaging, 

so that the water does not contact the sample. Open the containers and pour the entire 

contents into the chopper/homogenizer, except for frozen corn on the cob which requires 

removing the kernels from the cob using a clean dry knife or other appropriate utensil.

Mechanically chop just until a visually homogeneous mixture is attained. Refer to section 

5.2 for sample hold time prior to homogenization.

5.4.3 Juices/Concentrates

For fresh and reconstituted juices, ensure that the sample is evenly mixed to obtain a 

homogeneous mixture. For concentrates, dilute juice in a dry, clean container with cold 

running tap water, according to label directions. Mix well to ensure a homogeneous 

mixture.

Canned product concentrates (e.g., tomato paste) may be considered homogeneous and do 

not need to be mixed prior to weighing of analytical portion. Dilute appropriate analytical 

portion with sufficient water to facilitate sample extraction. Report results based on 
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undiluted concentrated product. Refer to section 5.2 for sample hold time prior to 

homogenization.

5.4.4 Dried Fruits

Open all the dried fruit package(s) into a container and mix or shake to obtain a 

representative analytical portion. Add enough water to cover the analytical portion and 

soak with water until re-hydrated. Prepare the analytical portion for extraction and analysis.

Unit counting is not required. Refer to section 5.2 for sample hold time prior to 

homogenization.

5.4.4.1 For raisins:

Raisins can be prepared following section 5.4.4, dried fruits. As an alternative, 

prepare raisins by opening all of the raisin package(s) into a container and mixing

or shaking to obtain a representative analytical portion. Grind the representative 

portion using a cryogrinder, cover it with water, mix thoroughly and freeze it. 

Prepare the analytical portion for extraction and analysis. Unit counting is not 

required. Refer to section 5.2 for sample hold time prior to homogenization.

5.4.5 Other Processed, Semi-Processed, Packaged Commodities

5.4.5.1 For other processed, packaged products that are homogenous, (e.g., corn 

syrup, peanut butter, baby food) proceed as follows:

• If the sample is comprised of a single container, simply weigh appropriate 

analytical portion.

• If the sample is comprised of multiple containers, combine and mix enough 

containers to achieve the commodity’s specified sampling size (e.g., 16 ounces 

for baby foods) and weigh appropriate analytical portion. Refer to section 5.2

for sample hold time prior to homogenization.

5.4.5.2 If a processed, packaged product appears non-homogeneous (e.g., 

separation of oil from peanut butter), ensure that the sample is evenly mixed prior 
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to weighing of analytical portion. Refer to section 5.2 for sample hold time prior to 

homogenization.

5.4.5.3 For semi-processed raw commodities (e.g., pre-washed, bagged spinach; 

peeled, cut carrots; etc.) refer to instructions in Section 5.3. Washing is not required.

5.4.5.4 For infant formula:

• For ready-to-eat samples, ensure that the sample is evenly mixed to obtain a 

homogeneous mixture.

• For concentrated liquid samples, dilute in a dry, clean container with reagent 

water, according to label directions and mix well to ensure a homogeneous 

mixture.

• For powdered samples, reconstitute in a dry, clean container with reagent water 

according to label directions and mix well to ensure a homogeneous mixture. 

Refer to section 5.2 for sample hold time prior to homogenization. 

5.4.5.5 For Eggs:

Crack open the eggs that make up the sample unit (minimum 10 eggs) into a clean 

blender/homogenizer. Discard the eggshells. Homogenize the eggs until a visually 

homogeneous mixture is attained. Refrigeration may not exceed 72 hours from the 

arrival time until the sample is homogenized.

5.4.5.6 For garbanzo beans, dried:

Open all the garbanzo bean package(s) into a container and mix or shake to obtain 

a representative analytical portion. Grind the representative portion using a 

cryogrinder or an appropriate device (e.g., Falling 3300 laboratory mill, Jacobsen 

grinder, UDY grinder). If using a cryogrinder, grind the representative portion, 

cover it with water, mix thoroughly and freeze it. Prepare the analytical portion for 

extraction and analysis. Unit counting is not required. Refer to section 5.2 for 

sample hold time prior to homogenization.

5.5 Weighing of Analytical Portion
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SOP No.: PDP-LABOP Page 33 of 42

Title: Sample Processing

Revision: 15 Replaces: 12/01/2022 Effective: 12/01/2023

The laboratory internal SOP shall define the weight required for the analytical portion. If the 

precision is ±1% or less, the laboratory may use the nominal target weight in further calculations.

5.6 Transshipment of Homogenate Subsamples

Specific details not addressed here may be worked out between the shipping laboratory, the testing 

laboratory, and/or MPD.

5.6.1 MPD designates which commodity homogenates shall be transshipped from one 

laboratory to another. Transshipments occur when required analyses (typically special 

procedures for single analytes or analyte classes) are not performed by the laboratory that 

receives the original collected sample. Rather than having PDP sampling staff split portions 

at the point of sample collection, laboratories split the sample at the point of 

homogenization. PDP and laboratory SOPs for handling, preparation, and custody shall 

apply to the subsamples destined for transshipping.

5.6.2 The testing laboratory designates the analytical portion size (e.g., by weight, 

volume, etc.) and the number of replicates necessary to perform their testing. The 

laboratories shall agree upon suitable containers and paperwork that needs to accompany 

the shipment. The shipping laboratory shall ensure that adequate analytical portions are 

provided to the testing laboratory by verifying that the agreed upon containers and fill 

volumes provide the minimum quantity needed for analysis. 

5.6.3 At the time of sample homogenization, the specified analytical portion is placed 

into the sample container and the container is labeled with the internal laboratory 

identification number. This information shall be recorded in permanent non-smearing ink 

or on waterproof, freezer-proof stickers. The homogenate subsamples shall then be stored 

at approximately -40 °C, or lower, at least overnight, until shipment.

5.6.4 On the day of shipment, homogenates and applicable paperwork are packaged 

tightly into shipping coolers with adequate blue ice and packing material to ensure they are 

received in satisfactory condition by the testing laboratory.

5.6.5 At a minimum, all samples shall be identified with both the PDP sample 

identification number and the internal laboratory identification number either directly (on 

the sample container) or indirectly (e.g., logsheets/worksheets). Appropriate chain-ofcustody forms and sample identification logsheets/worksheets (if used) shall be placed in 
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Pesticide Data Program

SOP No.: PDP-LABOP Page 34 of 42

Title: Sample Processing

Revision: 15 Replaces: 12/01/2022 Effective: 12/01/2023

a resealable plastic bag and included with the samples. If shipping to a non-PDP laboratory, 

the PDP Sample Information Form (SIF) shall not be included because it contains 

proprietary program site information.

5.6.6 Homogenates shall be shipped by overnight courier so that they arrive at the testing 

laboratory on a workday unless a weekend delivery has been agreed upon by the laboratory 

and MPD. The shipping laboratory shall notify the testing laboratory of the shipment. The 

shipping laboratory bears the cost of shipping. If the shipping laboratory requests the return 

of empty shipping coolers, the testing laboratory bears the cost of return.

5.7 Storage of Homogenate Subsamples

5.7.1 If it is not possible to extract the sample after homogenization the homogenized 

samples may be held for a period not to exceed 72 hours at approximately -20 °C or lower, 

or the homogenized sample may be held for longer periods of time at approximately -40

°C or lower, though the 90-day deadline for reporting requirement for final data is still in 

effect (see PDP DATA SOP Section 11.4.3).

5.7.2 One or more adequate portions of homogenized sample shall be held in reserve for 

reanalysis and/or confirmation as needed. The laboratory internal SOP shall define 

“adequate portion” and the distribution.

5.7.3 The reserve portions of violative samples shall be retained at approximately -40 °C

or lower until final QA review and successful RDE transmission. 

5.7.4 The reserve portion of all other samples shall be stored at approximately -40 °C or 

lower until final QA review and successful RDE transmission. An exception to this is 

allowed if blank homogenates need to be released early to serve as QC matrix. Also, if 

freezer space is limited, non-violative homogenates may be transferred to other freezers 

prior to final disposition. 

5.8 Storage of Extracts

Extracts shall be stored in appropriate containers (e.g., bottles, tubes, injection vials, etc.) and at 

appropriate temperature (approximately 4 °C or lower) for a period(s) as specified in the 

laboratory’s internal SOP to protect them from degradation and solvent evaporation.
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Pesticide Data Program

SOP No.: PDP-LABOP Page 35 of 42

Title: Sample Processing

Revision: 15 Replaces: 12/01/2022 Effective: 12/01/2023

Note: Vials held in active autosampler trays during instrumental analysis do not require 

refrigeration.

5.9 Disposal of Reserve Samples

The reserve sample may be discarded after time period(s) specified in Section 5.7 have elapsed.

Each laboratory shall establish the proper procedures for disposal of its reserve samples in an 

internal SOP.

5.10 Disposal of Extracts

The extracts may be discarded after time period(s) specified in the laboratory’s internal SOP have 

elapsed. Each laboratory shall establish the proper procedures for disposal (e.g., disposal by a 

licensed contractor) of its extracts in an internal SOP.
United States Department of Agriculture

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Pesticide Data Program

SOP No.: PDP-LABOP Page 36 of 42

Title: Sample Processing

Revision: 15 Replaces: 12/01/2022 Effective: 12/01/2023

Revised By: Chantal Rollerson Date

PDP Chemist

Monitoring Programs Division

1400 Independence Ave, SW 

Washington, DC 20250 

(202) 572-8172

Reviewed By: Sarva Balachandra Date 

Presiding Member of PDP Technical Advisory Group 

California Department of Food and Agriculture 

3292 Meadowview Rd 

Sacramento, CA 95832 

(916) 228-6857

Approved By: Brenda Foos Date

MPD Director, Monitoring Programs Division

1400 Independence Ave, SW 

Washington, DC 20250 

(202) 572-8167

Original signed by Chantal Rollerson 11/09/2023

Original signed by Sarva Balachandra 11/09/2023

Original signed by Brenda Foos 11/09/2023
United States Department of Agriculture

Agricultural Marketing Service, Science & Technology

Pesticide Data Program

SOP No.: PDP-LABOP Page 37 of 42

Title: Sample Processing

Revision: 15 Replaces: 12/01/2022 Effective: 12/01/2023

Revision 15 December 2023 Monitoring Programs Division

• Three memoranda removed from the references section because they are no longer available

• Added statement about tightly packed samples to section 5.1.12

• Added blackberries, tomatillos, and canned pumpkin to the table in section 5.3

• Clarified codes for head and leaf lettuce in the table in section 5.3

• Added blackberries to section 5.3.8

• Added new section 5.3.48 for tomatillos

• Renumbered the section headers in section 5.3 to accommodate the addition of tomatillos

• Added additional cleaning procedures for potatoes in section 5.3.41

• Clarified the use of water baths for frozen samples in section 5.4.2

• Updated the TAG approver information on the signature page 

Revision 14 December 2022 Monitoring Programs Division

• Changed USDA/AMS/MPD to MPD throughout document for clarification

• Changed SOP title from “Sample Processing and Analysis” to “Sample Processing” for clarification

• Removed PCNG from the references as it has been retired.

• Changed “Record number of units received” to “Record number of units homogenized” in the table in 

section 5.1

• Changed “sample identification” to “sample identification label” in sections 5.1.1.2 and 5.1.1.3.

• Removed “thawed commodity” language from section 5.1.3.5.

• Clarified the wording for determining sample weight in the note in Section 5.1.5 

• Added an example to section 5.1.6.1

• Changed the wording in the note in section 5.1.6.2 to remove the three-hour time window.

• Removed “if data is not available in RDE” from section 5.1.10 for clarification.

• Added the MPD email address to section 5.1.10

• Removed fact sheet references from section 5.2.4.

• Added the removal of debris from grains to section 5.3.20.

• Removed the 500g subsample requirement from section 5.3.20.

• Clarified the holding time for homogenized samples in section 5.7.1.

• Changed “MPD Sampling Team” to “PDP Sampling Team” throughout document for 

consistency.

• Updated “revised by PDP Chemist” signature line

• Updated the wording in the note under the Sample Receipt table.
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SOP No.: PDP-LABOP Page 38 of 42

Title: Sample Processing

Revision: 15 Replaces: 12/01/2022 Effective: 12/01/2023

Revision 13 December 2021 Monitoring Programs Division

• Updated formatting throughout the document 

• Updated section 4 to organize references alphabetically

• Updated “revised by PDP Chemist” signature line

• Changed “assure” to “ensure” throughout the document

• Changed “MPD Sampling Manager” to “MPD Sampling Team” throughout document

• Added MPD sampling team email address throughout document

• Added note regarding grain sample receipt information in RDE in section 5.1

• Removed “Federal Grain Inspection Service (FGIS) designee(s)” in section 5.1.8

• Removed references to faxing and to the obsolete FGIS form in section 5.1.10

• Added “a determination of” for clarification in section 5.1.12

• Added reference to Fact Sheet packing and shipping conditions for commodity storage in Section 

5.2.4 

• Added maximum time between sample arrival and homogenization in section 5.2.4

• Added reference to section 5.3 for maximum holding hours prior to homogenization in section 5.2.4

• Added section 5.2.7 for explicit storage conditions and maximum storage time for grain commodities

• Added frozen peaches (PZ) row to Table 5.3

• Added maximum refrigeration time to section 5.3.1

• Updated wording for preparation of grains for homogenization in section 5.3.20

• Added maximum time between sample arrival and homogenization in section 5.3.20

• Added preparation and homogenization instructions for pre-cut watermelon in section 5.3.50 

• Added reference to laboratory internal SOPs for extract storage time in Section 5.8

Revision 12 December 2020 Monitoring Programs Division

• Changed USDA/AMS to USDA/AMS/MPD throughout the document for clarification

• Added cross-referencing throughout the document

• Added reference links and a note indicating references were consulted in the preparation of 

this SOP in section 4

• Removed duplicate entry for reference to U.S EPA maintenance and calibration of equipment 

in section 4

• Added the full name and acronym for MPD in section 5

• Updated RDE entry language and changed the MPD name to acronym in section 5.1.1.2 

• Added the full name for eSIF acronym in section 5.1.1.3 

• Added clarification on selecting target weight for overweight samples received in section 

5.1.5.2

• Updated GIPSA organization to FGIS in sections 5.1.8.1 and 5.1.10
United States Department of Agriculture

Agricultural Marketing Service, Science & Technology

Pesticide Data Program

SOP No.: PDP-LABOP Page 39 of 42

Title: Sample Processing

Revision: 15 Replaces: 12/01/2022 Effective: 12/01/2023

• Updated section 5.2.4 to include sample hold time for commodities that require refrigeration 

prior to homogenization

• Updated SOP preparation and homogenization reference for corn syrup, eggs and infant 

formula in section 5.3

• Added frozen commodities for peas and dried fruits for plums in section 5.3 in the SOP 

preparation and homogenization section

• Updated commodity rinse language in sections 5.3.4 and 5.3.9

• Updated broccoli preparation in section 5.3.9

• Specified UDY as a grinder in section 5.3.20

• Removed duplicate papaya ripening language in section 5.3.32

• Added nectarine reference for consistency in section 5.3.33

• Added sample hold time reference prior to homogenization to sections 5.3.20, 5.41, 5.42, 

5.4.3, 5.4.4, 5.4.4.1, 5.4.5.1, 5.4.5.2, 5.4.5.4 and 5.4.5.6

• Added cryogrinding instructions and specified UDY as a grinder in section 5.4.5.6

• Updated sections 5.4.4, 5.4.5.6 and 5.6.2 for concise language 

Revision 11 December 2019 Monitoring Programs Division

• Updated MPD’s email address (section 5.1.8.2 and 5.1.8.3)

• Updated website for access to GIPSA’s Grain Sample Ticket Form, FGIS-920 in section 5.1.10

• Updated table in section 5.3 by adding basil, garbanzo beans (dried), mustard greens, radish, canned 

cranberry, canned and frozen sweet corn, canned and fresh green peas

• Updated table in section 5.3 for green peas variety and code, and SOP preparation and 

homogenization for raisins

• Updated table in section 5.3 by changing codes for frozen spinach, sweet, fresh corn and collard 

greens

• Added clarification to banana sample preparation in section 5.3.6

• Added basil to cilantro sample preparation in section 5.3.16

• Updated preparation instructions for grains (section 5.3.20)

• Updated hot pepper sample preparation in section 5.3.38

• Renumbered sections 5.3.43 through 5.3.49

• Added preparation instructions for radishes (section 5.3.43)

• Updated canned commodity sample preparation in section 5.4.1

• Added raisin sample preparation in section 5.4.4.1

• Added dried garbanzo bean sample preparation in section 5.4.5.6

• Updated extract disposal documentation requirement in section 5.10 

Revision 10 July 2018 Monitoring Programs Division

• Added preparation instructions for kiwi (section 5.3.24)
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Pesticide Data Program

SOP No.: PDP-LABOP Page 40 of 42

Title: Sample Processing

Revision: 15 Replaces: 12/01/2022 Effective: 12/01/2023

• Rearranged and renumbered commodities in section 5.3 to correspond to the table 

• In revision 9 history section, reversed snap peas and greens to correspond to sections 5.3.22 and 

5.3.35

• Added requirement for a procedure to dispose reserve samples in section 5.9

• Updated section 5.1.6.1 by changing the sample viability requirement for analysis

Revision 9 July 2017 Monitoring Programs Division

• Updated section 5.1.1.3 to remove requirement for duplicate labels – only one label required

• Added section 5.1.8.4 on capturing sample identity information for non-collected samples

• Updated table in section 5.3 by adding canned peaches and dried plums

• Updated table in section 5.3 by changing raisins from section 5.4.4.1 to section 5.4.4 

• Updated table in section 5.3 by adding codes for frozen cranberries and garbanzo (chick peas)

• Updated preparation instructions for greens and snap peas (sections 5.3.22 and 5.3.35)

• Removed section 5.4.4.1 and updated procedure from raisins to dried fruits

• Added preparation instructions for eggs (section 5.4.5.5)

Revision 8 July 2016 Monitoring Programs Division

• Updated section 5.1.8.3

• Added requirements for mixed lot numbers to section 5.1.1.2

• Added custody seals to section 5.1 and 5.1.3.5

• Updated section 5.3.2 

• Updated table in section 5.3 by adding canned olives, canned pineapples and frozen cranberries

• Removed 90 day storage requirement for violative samples in section 5.7.3

Revision 7 July 2015 Monitoring Programs Division

• Removed sections that referenced FSIS meat collection and water (no longer part of PDP collection 

programs

• Updated section numbering throughout 

• Updated title to section 5.1.8

• Added reference to work instructions in section 5

• Added requirement for laboratory to establish procedures to capture information from duplicate 

sample labels to section 5.1.1.3

• Added requirement for laboratory to contact MPD Sampling Manager if sample viability is in 

question to section 5.1.3

• Added option for estimated unit counting to section 5.1.3.4

• Included additional examples to section 5.1.3.5

• Updated section 5.1.8

• Removed references to commodities not tested by PDP from table in section 5.3
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Pesticide Data Program

SOP No.: PDP-LABOP Page 41 of 42

Title: Sample Processing

Revision: 15 Replaces: 12/01/2022 Effective: 12/01/2023

Revision 6 June 2014 Monitoring Programs Division

• Updated the document by replacing references of MP to MPD

• Added section 5.1.3.5 specifying MPD notification for samples with compromised integrity at receipt

• Updated table in section 5.3 by adding dairy-based and soy-based infant formula; salmon; and frozen 

blueberries, cherries, and potatoes

• Changed requirement throughout section 5.3 from “...allow to drain for at least 2 minutes on paper 

towels and a flat surface.” to “...allow to drain for at least 2 minutes.”

• Clarified broccoli preparation and homogenization requirement in section 5.3.9

• Added infant formula to section 5.4.5.4

• Changed reserve homogenate storage requirements in section 5.7.2

• Removed “-40” from section 5.7.4

• Corrected cross-reference in section 5.9

Revision 5 October 2012 Monitoring Programs Division

• Updated table in section 5.3 by adding avocados and raspberries

• Added avocados to Section 5.3.7 and renumbered remaining 5.3 sections

• Added raspberry to Section 5.3.8

• Renamed section 5.7 and added information on homogenate storage that was moved from section 5.3

Revision 4 July 2012 Monitoring Programs Division

• Updated purpose (section 1)

• Increased information presented in outline (section 3)

• Reorganized subsections in section 5.1 to reflect sample flow through the laboratory

• Updated RDE/SIF table in section 5.1 by adding “Required/Optional” column, clarifying 

specifications for required information 

• Clarified requirements for samples’ weights (section 5.1.6)

• Updated table in section 5.3 by adding codes for baby food applesauce, carrots, peaches, and peas 

• Clarified preparation and homogenization requirements for homogenous processed commodities in 

section 5.4.5.1

• Reordered sections 5.5, 5.6, and 5.7

• Renamed section 5.7 from “Storage of Reserve Homogenate Subsamples” to “Storage of Homogenate 

Subsamples”

Revision 3 July 2011 Monitoring Programs Division

• Updated the document by changing the MPO name with Monitoring Programs Division or 

Monitoring Programs (MP)

• Updated requirements for samples’ weights (section 5.1.8)

• Updated table in section 5.3 by adding papaya and renumbering the homogenization procedures
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Pesticide Data Program

SOP No.: PDP-LABOP Page 42 of 42

Title: Sample Processing

Revision: 15 Replaces: 12/01/2022 Effective: 12/01/2023

• Added section 5.3.30 as Papaya homogenization and renumbered all subsequent subsections

• Removed Note in section 5.5.3 referring to cap labeling

Revision 2 January 2011 Monitoring Programs Office

• Added the information required to be recorded in RDE/SIF as a table (in section 5.1)

• Updated requirements for recollection of samples (section 5.1.1)

• Eliminated the codes for animal tissue commodities and updated the example (section 5.1.4)

• Updated section 5.1.5 as to record in “Sample Comment” of RDE the preparation state of the fresh 

sample

• Updated section 5.1.6 as to record in “Lab Comment” of RDE the inadequacy of the received sample

• Updated section 5.1.7 as to record in “Reason NOT Analyzed” of RDE the lab’s inability to analyze 

the sample

• Updated section 5.1.8 as to record in the RDE sample information the date and person that received 

the sample

• Updated section 5.1.10 as to record in “# of Units” of RDE the number of units for non-clustered 

commodities

• Added centralized table with all commodities, their PDP codes and the SOP corresponding sections to 

their preparation and homogenization (section 5.3)

• Rearranged and renumbered the commodities in section 5.3 to correspond to the table

• Added Tangerines to citrus group (section 5.3.29)

• Added preparation instruction for Snap Peas (section 5.3.33)

• Updated preparation instructions for Anaheim Hot Peppers to have the core and seeds removed 

(section 5.3.35).

• Added instruction for cherry tomatoes preparation (section 5.3.44)

• Added baby food as another example in the processed foods section (5.4.5)

• Eliminated the transshipping amounts from section 5.5.2

• Updated homogenized sample container labeling (section 5.5.3)

• Updated the retention time of violative samples from 6 months to 90 days (section 5.6.2)

• Updated requirement for -40°C homogenate subsamples’ storage (section 5.6.3)

• Updated the weight and precision of analytical sample (section 5.7)

Revision 1 September 2010 Monitoring Programs Office

• Added preparation instructions for Hot Peppers (section 5.3.25).

• Added instruction for soybean transshipping (section 5.5.2).