Cereals and cereal products Sampling Simplified routine method

Transcription

1 CEN/TC 338 Date: TC 338 WI CEN/TC 338 Secretariat: AFNOR Cereals and cereal products Sampling Simplified routine method Getreide und Getreideerzeugnisse Probenahme Vereinfachte Routineverfahren Céréales et produits céréaliers Échantillonnage Méthode simplifiée de routine ICS: Descriptors: Document type: European Standard Document subtype: Document stage: Working Document Document language: E M:\dp\PPN\Equipe\HP\WI00338xxx\TC_338_WI_(E)-validated BR-oct2011.doc STD Version 2.4a

2 Contents Page Foreword...4 Introduction Scope Terms and definitions General requirements Sampling equipment and devices Sampling General Sampling of bulk products General Sampling of flowing bulk products Sampling of static bulk products Number and weight of grain samples Number and weight of samples of milled products and other cereal products Sampling of milled products and other cereal products in prepackaged units Crates and boxes or sacks and bags for sampling Incremental samples or prepackaged units Number and weight of samples Laboratory sample Homogenisation Division of the aggregate sample The cone and quarter method Sample dividers Packaging and labelling of samples General Labels for samples Information Shipment of samples Sampling report Health and safety Annex A (informative) Examples of mechanical sampling devices used for flowing grain A.1 Cross-cut sampling devices A.2 Full-flow diverter-type sampling devices A.3 Rotating cup sampling devices A.4 Bucket elevator sampling devices Annex B (informative) Examples of sampling devices used for static products and dividers B.1 Cereal sampling devices B.1.1 Sampling devices used to sample static bulk products in mobile tanks and rigid containers B.1.2 Sampling devices used to draw samples from sacks or bags, including bulk sacks B.2 Sampling devices used to sample milled products, excluding granular products B.2.1 Sampling devices used to sample static bulk products B.2.2 Sampling devices used to take samples from sacks and bags B.3 Instruments for dividing laboratory samples B.3.1 Straight metallic parts

3 B.3.2 Multiple-slot dividers (with partitions or blades)...28 B.3.3 Conical dividers (Boerner type)...29 B.3.4 Mechanical centrifugal divider...30 B.4 Guide to sampling devices suitable for sampling cereals and cereal products...31 Bibliography

4 Foreword This document (TC 338 WI ) has been prepared by Technical Committee CEN/TC 338 Cereal and cereal products, the secretariat of which is held by AFNOR. This document is a working document. 4

5 Introduction Sampling is a procedure that requires both a method and equipment that are suitable for the task. Any analysis of the characteristics of a lot and any interpretation of the results would prove futile if the sample were not representative of the lot from which it was taken. Sampling is a delicate procedure that requires a great deal of care. It is strongly recommended that the task be entrusted to personnel who have been previously trained to use the appropriate equipment. 5

6 1 Scope This document is applicable to the dynamic or static sampling, by manual or mechanical means, of cereals and cereal products for assessment of their quality and condition. It is applicable to sampling for the determination of heterogeneously distributed contaminants, undesirable substances and parameters usually homogenously distributed, such as those used to assess quality or compliance with a specification. It can be used to determine insect infestation in a grain lot, although it is recommended to assess harmful insect populations by trapping whilst grain is in storage. Methods for assessing insect populations are provided in the standards NF V [13] and ISO [14]. This document is not applicable to seeds or genetically modified organisms (GMO). NOTE 1 The sampling of seeds is governed by the rules established by the ISTA (International Seed Testing Association). NOTE 2 At the time of publication of this document, there is no study to support the inclusion of GMOs in the scope of this document. 2 Terms and definitions For the purposes of this document, the following terms and definitions apply. 2.1 lot Identified quantity of product (cereals or cereal products) on which a sampling check is carried out to determine one (or several) given characteristic(s) 2.2 sampling act of constituting a final sample that is representative of the lot and intended for shipment to the laboratory or for preservation 2.3 incremental sample a small quantity of grain taken at each individual sampling point in a lot 2.4 aggregate sample a section of the entire lot comprised of one (or several) individual incremental sample(s) drawn randomly from the lot, combined together and mixed 6

7 2.5 laboratory sample sample obtained by homogenisation and division of the aggregate sample 2.6 homogenisation effective mixing by mechanical or manual means such that the contaminants and the physical properties are distributed randomly within the aggregate sample or the laboratory sample 2.7 prepackaged unit quantity of grain or cereal products packaged in a sack, bag or retail packing 2.8 sampling error difference between the characteristics of the sample and those of the lot due to: heterogeneity; errors associated with the sampling equipment; the sampling method. NOTE A sample is merely a representation of a lot. 3 General requirements 3.1 Under the present national standard, sampling is comprised of the following stages: the drawing of a defined number of incremental samples with a view to constituting an aggregate sample; the homogenisation of the aggregate sample; the reduction of the aggregate sample into one (or several) laboratory sample(s). 3.2 Given that the composition of cereal lots is rarely homogenous and that certain contaminants are distributed in a non-uniform manner, a sufficient number of incremental samples must be taken. These must be carefully mixed to create an aggregate sample from which it will be subsequently possible to obtain one (or several) laboratory sample(s). For static products, particular care must be taken to ensure that these incremental samples are distributed evenly throughout the quantity of grain, both on the surface and at depths. 3.3 Precautions must be taken to ensure that all of the equipment used is clean, dry and free of foreign odours. The sampling procedures must be carried out so as to protect the drawn products from any source of accidental contamination caused by rain, dust, etc. 3.4 All of the sampling procedures must be carried out within a sufficiently short period of time to prevent any alteration to volatile substances present in the samples. If one of the sampling stages takes too long, the individual or mixed incremental samples must be kept in hermetically sealed clean recipients. 3.5 In the event of arbitration, the samples must be jointly drawn by representatives of the buyer and the seller, or by a third party appointed by common agreement. 3.6 Precautions must be taken to guarantee the integrity of all samples between drawing and analysis. 7

8 4 Sampling equipment and devices Numerous sampling equipment items and devices exist. The most appropriate equipment should be chosen by taking into account the product to be sampled, the quantity required and the recipients to be used. Appendix A gives a description of the general types of mechanical sampling devices used for flowing grain and contains illustrations of examples of such devices. Appendix B gives examples of devices used for the sampling of static products and examples of instruments used for the division of samples. Appendices A and B are purely informative and do not exhaustively list existing devices. Mechanical samplers must allow easy access for the examination, cleaning, maintenance and repair of all surfaces subject to wear. It is advisable that means of access are constructed from materials that do not generate an electrostatic charge. In the case of maize, it is advisable that vacuum samplers feature a dual tube with an air supply. 5 Sampling 5.1 General The sampling of bulk products concerns both the drawing of flowing cereals and the drawing of static cereals. In both cases, the sample can be drawn by mechanical or manual means. The sampling of lots in prepackaged units (2.7) is always static sampling and only employs manual means. The number of incremental samples and the weights are indicated in Tables 1 and 2 for grain, in Tables 3 and 4 for milled products and other cereal products and in Table 5 for milled products and other cereal products in prepackaged units. A laboratory sample (2.5) is necessary per lot or sublot of 1,500 t maximum. NOTE 1 For example: for a lot of 6,000 t, four laboratory samples are required for analysis. NOTE 2 The sample weights indicated in Tables 1 to 5 are taken from data from the Technical Report CEN ISO/TR Sampling of bulk products General Insofar as is possible, it is advisable to carry out sampling when the products are flowing (for example, during loading or unloading) so that all of the sections constituting the lot have the same probability of being sampled. If mechanical means are not available, a manual sampling plan must be implemented. The methods (mechanical or manual) for taking samples from flowing lots must be adapted to the speed at which the product flows (see Tables 1 and 3). For static grain, when the equipment used does not allow a sample to be taken throughout the entire depth of the mass of grain, it is necessary to carry out sampling when the mass is flowing. 8

9 For trucks and articulated lorries, given the high speed of unloading, it is recommended to take samples in a static manner. To ensure that the overall sample is representative of the lot, the number of incremental samples must be as high as possible. Tables 1 to 4 state the minimum number of samples to be drawn according to the situation Sampling of flowing bulk products Because the characteristics and composition of the lot may vary, incremental samples must be taken from the entire lot, i.e. during the entire duration of grain flow. In the case of mechanical sampling, the equipment must be adjustable so that the size of the incremental samples and/or the sampling frequency can be varied over a wide range. A series of incremental samples of a defined size must be drawn at predetermined intervals in accordance with the flow and in such a way that each section of the lot has the same probability of entering into the sampling device. NOTE For example, cross-cut sampling devices meet this requirement regardless of the flow's form. In the case of manual sampling, the incremental samples must be taken at regular intervals Sampling of static bulk products In the case of static sampling, the means and methods for drawing samples must take into account the depth of the product to be sampled: up to a depth of 2 m, manual probes may be used; up to a depth of 2.5 m, mechanical samplers may be used if the sampling principle upon which they operate does not create segregation at the entrance to the probe's tube and if they do not damage the grain; if the depth of the product exceeds 2.5 m, only suction sampling probes may be used. At the time of release of this document, available equipment allows a maximum depth of 9 m to be reached without excessive difficulty for the operator. Whatever the sampling method used, incremental samples should be drawn at regular intervals across the entire breadth and throughout the entire depth of the lot. It is recommended to carry out sampling throughout the entire depth of the lot using a gridding method (see Figure 1). At the current state of technology, the sampling probes used for grains are not suitable for powdery products such as flour Number and weight of grain samples Number and weight of incremental samples The minimum number and the weight of the incremental samples are stated in Tables 1 and 2. All of the incremental samples combined constitute the aggregate sample, which must be homogenised and divided (6.1 and 6.2) to constitute the laboratory sample Weight of the laboratory sample The recommended weight of a laboratory sample is determined by the type and the requirements of the tests to be performed (see Tables 1 and 2). 9

10 For contaminant analysis, the weight of the laboratory sample must be between 3 kg and 10 kg. However, in the case of sampling carried out to determine DON, the weight of the laboratory sample may be 1 kg. For analysing other characteristics, it must be at least 1 kg (3 kg for samples taken for experimental milling) Sampling of flowing bulk products Sampling by mechanical or manual means The mechanical sampling device must be adjusted so that an incremental sample of the size specified in Table 1 below can be obtained. The size of the incremental drawings and the samples is provided as a guideline only and is not intended as a substitute for national requirements or specifications. Table 1 Sampling procedure for obtaining the minimum weight of a laboratory sample in the case of flowing grain Sampling of flowing grain by mechanical or manual means Weight of incremental samples MINIMUM number of incremental samples a Minimum weight of the laboratory sample for contaminant analysis Minimum weight of the laboratory sample for other analyses Mechanical sampling 300 g to 1,900 g 10 per lot or sublot of 500 t 15 per lot or sublot of 1,500 t for lots of a large size over 1,500 t Manual sampling 300 g to 1,900 g For contaminants: 10 per lot or sublot of 500 t 15 per lot or sublot of 1,500 t for lots of a large size over 1,500 t For other analyses: For ochratixin A and aflatoxins 10 kg For pesticides, heavy metals and dioxins: 1 kg For other contaminants b : 3 kg 1 kg to 3 kg depending on analytical requirements 3 per lot or sublot of 500 t 4 per lot or sublot of 1,500 t for lots of a large size over 1,500 t a Examples of sampling frequency according to the grain flow rate: for a lot of 500 t and a flow rate of 500 t per hour, the sampling frequency shall be one incremental sample every 6 mins; for a flow rate of 250 t per hour, the frequency shall be one every 12 mins. b Other contaminants such as DON, fumonisins, zearalenone; in the case of sampling carried out to determine DON, the weight of the laboratory sample may be 1 kg Sampling of static bulk products The number of samples to constitute for laboratory analysis and arbitration must be agreed upon between the parties concerned. The minimum number and the size of the incremental samples is stated in Table 2. Figure 1 gives an example of the distribution of sampling points for 8 points. 10

11 If the weight of the laboratory sample cannot be achieved, the number of incremental samples must be increased. Table 2 Sampling procedure for obtaining the minimum recommended weight of a laboratory sample in the case of static bulk grain Sampling of static bulk grain (mechanical sampling systems recommended) in articulated lorries or trucks, wagons, storage ships or tanks, silos or warehouses Size of the lot or sublot Weight of incremental samples a MINIMUM number of incremental samples b Minimum weight of the laboratory sample for contaminant analysis Minimum weight of the laboratory sample for other analyses 30 tonnes 3 sampling points < 30 tonnes to 45 tonnes 4 sampling points < 45 tonnes to 100 tonnes 6 sampling points For ochratixin A and aflatoxins 10 kg < 100 tonnes to 300 tonnes < 300 tonnes to 500 tonnes < 500 tonnes to 1,500 tonnes 400 g to 3,000 g 7 sampling points 8 sampling points 10 sampling points per 500 t For pesticides, heavy metals and dioxins: 1 kg For other contaminants b : 3 kg 1 kg to 3 kg depending on analytical requirements per lot or sublot of 1,500 tonnes 10 sampling points a In the case of sampling by mechanical means, the weight of the incremental samples must be adapted to the equipment. b For bulk grain with a large depth, a sample taken every 2 m at the same sampling height corresponds to an incremental sample. Repeat the procedure as many times as necessary. c Other contaminants such as DON, fumonisins, zearalenone; in the case of sampling carried out to determine DON, the weight of the laboratory sample may be 1 kg. Figure 1 Example of the distribution of sampling points for 8 points Number and weight of samples of milled products and other cereal products The minimum number and the size of the incremental samples are stated in Tables 3 (flowing products) and 4 (static products). 11

12 Table 3 Sampling procedure for obtaining the minimum weight of a laboratory sample in the case of flowing milled products and other cereal products Mechanical sampling Sampling of flowing milled products and other cereal products by mechanical or manual means Manual sampling INDICATIVE weight of the incremental sample 300 g to 1,900 g 300 g to 1,900 g MINIMUM number of incremental samples 5 per sublot of 100 t (frequency according to the flow of the circuit) 5 per sublot of 100 t i.e. for a flow rate 20 t/hr: minimum of 1 per hour i.e. for a flow rate > 20 t/hr : minimum of 1 per 20 t Minimum weight of the laboratory sample for contaminant analysis For powdery products 1 kg For compressed products (for example: pellets etc.): 3 kg Minimum weight of the laboratory sample for other analyses 1 kg to 3 kg depending on analytical requirements NOTE 1 Additional incremental samples may be necessary to achieve the minimum weight of the laboratory sample. NOTE 2 As it is commonly acknowledged that powdery products are more homogenous than grain, a laboratory sample of 1 kg is sufficient for contaminant analysis. Table 4 Sampling procedure for obtaining the minimum recommended weight of a laboratory sample in the case of static milled products and other cereal products Sampling of static milled products and other bulk cereal products (mechanical sampling systems recommended) in articulated lorries or trucks, wagons Size of the lot or sublot 15 tonnes INDICATIVE weight of the incremental sample MINIMUM number of incremental samples 1 sampling point < 15 tonnes to 30 tonnes 1 sampling points per compartment < 30 tonnes to 45 tonnes 400 g to 3,000 g 2 sampling points per compartment > 45 tonnes 3 sampling points per compartment Minimum weight of the laboratory sample for contaminant analysis For powdery products 1 kg For compressed products (for example: pellets etc.): 3 kg Minimum weight of the laboratory sample for other analyses 1 kg to 3 kg depending on analytical requirements NOTE 1 Additional incremental samples may be necessary to achieve the minimum weight of the laboratory sample. NOTE 2 As it is commonly acknowledged that powdery products are more homogenous than grain, a laboratory sample of 1 kg is sufficient for contaminant analysis. It is recommended to sample flowing milled products and other cereal products during manufacturing or shipping. Sampling in silos is not recommended. 12

13 5.3 Sampling of milled products and other cereal products in prepackaged units Crates and boxes or sacks and bags for sampling A lot is made up of a series of base units ("prepackaged units") taken from one (or several) manufacturing source(s) all bearing the same identification code on the individual packaging for traceability purposes. The prepackaged units are usually transported in crates or boxes or on pallets containing an appropriate number of base units. The method applicable to sacks (described in 5.3.3) must be used to define the appropriate number of crates, boxes or palettes for sampling Incremental samples or prepackaged units The prepackaged unit constitutes an incremental sample, drawn at random from the lot selected for sampling. It is important to avoid selecting prepackaged units that are in the same position in several crates, boxes or palettes Number and weight of samples The incremental samples shall be taken from the middle and throughout the entire depth of each prepackaged unit for sampling using a slender sampling probe specially designed for sacks (see Appendix B, B.1.2). They shall be taken from the number of sacks specified below. The following formula shall be used as a guide for the sampling of lots packaged in individual packaging (sacks, retail packing, etc.): F( n) = mb mi ma mp where F(n) is the sampling frequency per lot: incremental sample to be taken every n th sacks or bags (decimal points should be rounded to the nearest whole number); n being the number of prepackaged units between two incremental samples; m B is the weight of the lot, expressed in kilogrammes (kg); m I is the weight of the incremental samples, expressed in kilogrammes (kg); around kg; m A is the weight of the aggregate sample, expressed in kilogrammes (kg); for contaminant analysis, around 1 kg for powdery products and 3 kg for compressed products (for example: pellets etc.); 1 kg for other analyses; m P is the weight of the individual prepackaged unit, expressed in kilogrammes (kg). A practical example of calculating a sampling frequency for a lot of 25 tonnes is given in Table 5 and Figure 2. 13

14 Table 5 Sampling procedure for obtaining the minimum recommended weight of a laboratory sample in the case of milled products and other cereal products in individual prepackaged units: practical examples for a lot of 25,000 kg Weight of individual sacks Weight of the incremental sample Sampling frequency calculated for contaminant analysis of compressed products (for example: pellets etc.) (n) (kg) (kg) 1 incremental sample every "n" preconditioned units Sampling frequency calculated for contaminant analysis of powdery products or for other analyses of any type of product (n) 1 incremental sample every "n" preconditioned units i.e. 1 per palette 2,500 i.e. 1 per palette i.e. 5 per palette 500 i.e. 2 per palette i.e. 24 per palette 100 i.e. 8 per palette i.e. 38 per palette 63 i.e. 13 per palette i.e. 48 per palette 50 i.e. 16 per palette One incremental sample per palette or packaging item is the minimum required regardless of the type of lot. Figure 2 Examples of the distribution of sampling points for a sampling frequency F(n) of 17 6 Laboratory sample 6.1 Homogenisation The aggregate sample must be carefully mixed before carrying out any division aimed at obtaining the laboratory sample. NOTE Dividing the sample without prior homogenisation will result in a non-representative laboratory sample. 6.2 Division of the aggregate sample Reduce the aggregate sample with a view to obtaining the required number of laboratory samples of a determined weight (see Tables 1 to 4 in and 5.2.5) using a method and/or equipment enabling the obtainment of representative laboratory samples. Examples are provided in to and in Appendix B, B.3. Other equipment may be used in the case of aggregate samples of a very large size, although it must be capable of producing representative laboratory samples. The equipment must be carefully cleaned between each sample to prevent cross-contamination. 14

15 6.2.1 The cone and quarter method a) Thoroughly mix the aggregate sample by repeating steps b) and c) at least twice before carrying out the division described in steps c) and d). Work on a clean, non-absorbent surface. b) Gather the grain together to form a conical pile. c) Flatten the top of the pile, then divide the pile into quarters. d) Remove the two diagonally opposite quarters (B and C) and mix the two remaining quarters (A and D) (see Figure 3). e) Repeat the entire process until a laboratory sample of the required size is obtained Sample dividers The divider must be used on a flat surface Conical divider Figure 3 Cone and quarter method To reduce an aggregate sample, use a device featuring a supporting structure if necessary and use receptacles or pots for collecting the divided samples. a) Thoroughly mix the sample by repeating steps b) and c) at least three times and remixing the subsamples in the hopper. b) Pour the aggregate sample into the hopper. c) Two sub-samples are obtained in the two receptacles (or pots). d) Keep the content of one of the two receptacles. e) Reposition two empty receptacles. Repeat steps a) to e) as many times as necessary, using the sub-sample obtained in d) and alternating the receptacles to be kept until a laboratory sample of the required size is obtained Centrifugal divider Start the centrifugal divider. Pour the aggregate sample into the upper hopper. Proceed as instructed in c) to e) above. Repeat steps a) to e) as many times as necessary, alternating the receptacles until a laboratory sample of the required size is obtained. 15

16 Partition divider Partition dividers must only be used for small samples (less than 2 kg). Proceed as instructed in c) to e) above. Repeat steps a) to e) as many times as necessary, alternating the receptacles until a laboratory sample of the required size is obtained. 7 Packaging and labelling of samples 7.1 General Laboratory samples must be placed in clean containers suitable for the quantities required for all tests that need to be subsequently carried out and in order to preserve their original characteristics. Ideally, these containers must be completely filled and hermetically sealed so as to prevent any damage. If present, the seals must be tamper-proof and identifiable. 7.2 Labels for samples The information stated below must be marked indelibly and legibly. 7.3 Information The information on the labels on the laboratory sample must contain the instructions required by agreement between the parties concerned, for example: a) the nature of the product; b) the quantity represented; c) the lot identifier; d) the contract number (if applicable); e) the sampling date; f) the location and point of sampling; g) the name of the person who carried out the sampling. 8 Shipment of samples Samples should be sent to the laboratory as quickly as possible. The samples should be kept and transported in conditions appropriate for the preservation of their integrity. 9 Sampling report The sampling report may contain some or all of the following information: the sampling date; the name and signature of the individuals authorised to carry out sampling; 16

17 if necessary: the name and signature of the seller; the name and signature of the buyer; the name and signature of the deliverer; the description of the product, including: the reference number of the sample; the sample weight; the size of the lot; the origin of the sample (for example: flat storage, vertical silo, truck, etc.); a description of the sampling operation, including: the location and points of sampling; the number of incremental samples per lot; the number of laboratory samples per lot; the sampling procedure used (equipment, static/flowing, etc.); the destination of the sample, e.g. the name and address to which the samples are to be sent; any additional comments; the sample transportation and storage method (for example, refrigerated). 10 Health and safety The sampling device used must comply with the safety requirements in place and, in particular, must be sufficiently lit for inspection work, operation and maintenance. It is recommended to wear an appropriate respiratory mask if the device is used in an environment containing dust emanations. WARNING It is dangerous to walk on grain stored in a storage bin, in the holds of ships, in silos or in trucks. In some cases, the atmosphere in silos may be asphyxiating or toxic due to the accumulation of gases caused by the metabolism of grains or the presence of fungal species. Local legislation and industrial safety standards must be observed. 17

18 Annex A (informative) Examples of mechanical sampling devices used for flowing grain Appendix A describes the general types of mechanical sampling devices used for flowing grain and illustrates a few examples of such devices. A.1 Cross-cut sampling devices Cross-cut sampling devices allow a complete cross-section of a falling grain flow to be taken. They may be open-nozzle sampling devices (see Figure A.1), tubular sampling devices with adjustable apertures (see Figure A.2) or tubular sampling devices with a worm screw (see Figure A.3). Key 1 Nozzle 2 Sampling device 3 Grain Figure A.1 Open-nozzle cross-cut sampling device, ensuring intermittent, repeated sampling 18

19 Key 1 Sample divider 2 Sample flow 3 Return of excess grains into the system Figure A.2 Tubular cross-cut sampling device with adjustable apertures Key 1 Grain flow 2 Worm screw 3 Sample flow Figure A.3 Tubular sampling device with worm screw 19

20 A.2 Full-flow diverter-type sampling devices In this type of sampling device, a flap or shutter intermittently redirects the entire grain flow (see Figure A.4). Key 1 Sample flow 2 Flap or shutter Figure A.4 Full-flow diverter-type sampling device A.3 Rotating cup sampling devices The falling grain flow is intermittently sampled by a cup rotating around a central vertical axis (see Figure A.5). Key 1 Grain flow 2 Vertical chute 3 Rotating cup 4 Flow 5 Sample flow Figure A.5 Rotating cup sampling device 20

21 A.4 Bucket elevator sampling devices This type of sampling device draws grain from a moving belt or a conveyor. Buckets travelling in a continuous loop draw samples over the entire width of the grain flow, as the configuration of the lateral rollers concentrates the grain on the belt. The samples are delivered into the reception hopper when the buckets pivot around the upper roller (see Figure A.6). Key 1 Sampling bucket(s) 2 Sampling bucket belt 3 Belt guide 4 Balance weights 5 Special roller 6 Sample receptacle 7 Conveyor roller 8 Carrier belt 9 Safety panel 10 Hopper NOTE As they are elevated, the buckets sample the grain from the carrier belt and, after pivoting around the upper roller, deposit the samples into the hopper. Figure A.6 Bucket elevator sampling device 21

22 Annex B (informative) Examples of sampling devices used for static products and dividers Appendix B provides examples of sampling devices used to sample static products and instruments used to divide samples. B.1 Cereal sampling devices B.1.1 Sampling devices used to sample static bulk products in mobile tanks and rigid containers B Manual concentric tapered probes a) Open or closed shaft: with one or several apertures Figure B.1 Open shaft with single aperture Figure B.2 Open shaft with several apertures or closed shaft with compartments and several apertures b) Open shaft with sequentially staggered apertures: several apertures Figure B.3 Open shaft with several sequentially staggered apertures 22

23 B Gravity-fill probes with extension rods and T-shaped handles a) Gravity-fill probe: concentric b) Gravity-fill probe: cup-type Figure B.4 Concentric gravity-fill tapered head probe Figure B.5 Cup-type (head shown in open position) B Mechanical sampling devices There are three main categories of mechanical sampling devices: a) Gravity-fill sampling device Figure B.6 Gravity-fill sampling device 23

24 b) Suction sampling device (sometimes called "vacuum sampling device") EXAMPLE Sampling from a truck 24

25 Key 1 Sample 7 Coupling 2 Quantity of grain 8 Additional length 3 Porous head unit 9 Automatic discharge 4 Air 10 Sample tank 5 Grain sample 11 Vacuum chamber 6 Sampling head unit 12 Duct Figure B.7 Suction (or "vacuum") sampling device 25

26 c) Pneumatic sampling device (not shown). B.1.2 Sampling devices used to draw samples from sacks or bags, including bulk sacks B Tapered dynamic sampling probes for sacks Minimum diameter: 17 mm; aperture: 40 mm 15 mm. Figure B.8 Tapered dynamic sampling probe for sacks B Walking-stick probe Concentric tubes, minimum diameter: 20 mm: a) open shaft: with one or several apertures; b) with compartments: with one or several apertures. Figure B.9 Walking-stick concentric probe for sacks: with open shaft and several compartments B Conical sampling device Figure B.10 Conical sampling device 26

27 B Gravity-fill probes with extension rods and T-shaped handles for open-topped sacks (Figures B.4 and B.5) B Archimedes' screw probe These probes are generally small, portable and electric. Figure B.11 Archimedes' screw probe (portable) B.2 Sampling devices used to sample milled products, excluding granular products B.2.1 Sampling devices used to sample static bulk products Identical to those used to sample cereals (B.1.1), with the exception of mechanical sampling devices. Only two types of mechanical sampling devices are suitable for the sampling of milled products: a) Electromechanical Archimedes' screw probe (Figure B.12) Figure B.12 Electromechanical Archimedes' screw probe b) Mechanical gravity-fill sampling probe (Figure B.6) 27

28 In general, pneumatic sampling devices are not suitable for this use. B.2.2 Sampling devices used to take samples from sacks and bags Identical to those used to sample cereals (B.1.2). B.3 Instruments for dividing laboratory samples Made from materials that are not liable to contaminate the samples. B.3.1 Straight metallic parts B.3.2 Multiple-slot dividers (with partitions or blades) a) Small laboratory dividers for milled samples: Minimum of 12 slots; channels measuring 12.7 mm. b) Average dividers for grain cereal samples: Minimum of 18 slots; channels measuring 12.7 mm. Figure B.13 Straight metallic part Figure B.14 Partition divider: multiple-slot divider (with partitions and blades) with two receptacles 28

29 B.3.3 Conical dividers (Boerner type) Figure B.15 Conical divider (Boerner type) 29

30 B.3.4 Mechanical centrifugal divider Enables multiple samples to be obtained simultaneously. Key 1 Loading hopper 2 Rotating channel 3 Driving motor 4 Conical hopper with 8 apertures 5 Collection of sub-samples 6 Sub-sample collection channel 7 and 8 Two receptacles for sub-sample collection 9 Draining of excess grains, grains to be replaced in the divider 10 Adjustment of shutters to alter the division factor 11 One of the 8 adjustable apertures Figure B.16 Mechanical centrifugal divider 30

31 B.4 Guide to sampling devices suitable for sampling cereals and cereal products Storage conditions Static bulk products in silos, bins and warehouses Wagons, ships and containers for the transportation of bulk products Cereals in grain form Reference to figures in Appendix B Milled products and other cereal products B.1, B.2, B.3, B.4, B.5, B.6, B.7 B.12 B.1, B.2, B.3, B.4, B.5, B.6, B.7 B.12 Tote bags and rigid containers B.1, B.2, B.3, B.4, B.5, B.6, B.7 B.12 Sacks and bags (textile fibre, paper and plastic) NOTE B.4, B.5, B.8, B.9, B.10, B.11 B.8, B.9, B.10, B.11, B.12 The minimum dimensions of the sampling devices are given for information purposes only. 31

32 Bibliography [1] EN ISO 13690, Cereals, pulses and milled products Sampling of static lots [2] EN ISO 6644, Cereals and milled products from flowing cereals Automatic sampling by mechanical means [3] EN ISO 542, Oilseeds Sampling [4] EN ISO 664, Oilseeds Reduction of the laboratory sample to a sample for testing [5] Commission Regulation (EC) no. 401/2006 of 23 February 2006 laying down the methods of sampling and analysis for the official control of the levels of mycotoxins in foodstuffs. [6] Commission Regulation (EC) no. 466/2001 of 8 March 2001 setting maximum levels for certain contaminants in foodstuffs. [7] Commission Directive 2002/63/EC of 11 July 2002 establishing Community methods of sampling for the official control of pesticide residues in and on products of plant and animal origin and repealing Directive 79/700/EEC. [8] Commission Directive 2002/70/EC of 26 July 2002 establishing requirements for the determination of levels of dioxins and dioxin-like PCBs in feedingstuffs. [9] Commission Recommendation 2004/787/EC of 4 October 2004 on technical guidance for sampling and detection of genetically modified organisms and material produced from genetically modified organisms as or in products in the context of Regulation (EC) no. 1830/2003. [10] Gafta no. 124 of the Grain and Feed Trade Association "Sampling rules: rules for sampling, analysis instructions and analysis certification". [11] CEN ISO/TR ), Cereals and cereal products Sampling studies [12] EN ISO ), Cereals and cereal products Sampling [13] NF V , Cereals and pulses Determination of hidden infestation by insects. [14] ISO 16002, Cereals in grain form and stored pulses Guidelines for the detection of infestation by living invertebrates by trapping 1) In preparation. 32