Standardization of results reporting

The objective of an LSMBS is not simply to collect and analyze samples of selected products. To be of value, the results of the analyses must be reported, and standardization in reporting of intermediate and final results is critical to the success of the overall project. Each laboratory should determine exactly the same analytical parameters, calculate results in exactly the same way, and present both inputs to and outcomes of the calculations in exactly the same format. 

The OPMBS used a custom-written spreadsheet application, i.e., a workbook, in conjunction with laboratory automation systems to standardize data recording, calculations, and presentation of results. Devising this approach required careful differentiation between (a) the workbook used to calculate and report the results and (b) the data acquisition systems used in each laboratory. The laboratory systems were used to collect the raw chromatographic data, but the calculation modules in the laboratory systems were not used. Instead, all calculations were done in the workbook. Use of the laboratory systems to collate and output the final results was considered but was rejected for two reasons. First, different laboratories used different systems, and some laboratories used more than one system. The output characteristics of the various systems differed considerably and would have required extensive modification 

Each commodity required a specifically customized workbook, containing a worksheet for each analyte determined in the commodity. Each laboratory received electronic copies of either three or four workbooks, which served as templates for the three or four commodities assigned to the laboratory. Each set of up to 10 commodity samples scheduled for colleetion and analysis required the creation of a copy of the appropriate template. Each workbook template contained one primary worksheet for each analyte, in which analytical data were recorded and residue levels were calculated, as described below. Eor example, the template for green beans contained 17 primary worksheets, one for each of the 17 analytes determined in each green bean sample. Additional worksheets were inserted into copies of the template as needed, to describe results of further analyses, such as confirmation of analytes present above the limit of quantitation (LOQ) or dilutions to bring the concentration of the analyte into the calibration range. 

In addition, each workbook contained a summary table of all results and limit of detection (LOD) determinations. The table was organized with sample identifications in the left-hand column. Eor each analyte, the analytical result and the LOD appeared in adjacent columns, and analyte recoveries appeared above the results columns. The summary table was generated automatically from the analytical results in the individual worksheets, without operator intervention or re-entry of any information. 

Information from the summary table in each workbook was directly imported into a master compilation of analytical results. The compilation could then be manipulated as desired to present the data in various ways. For example, the compilation could be searched for the number of apple samples that contained no detectable residues of any analyte or for the number of tomato samples that required dilution and reanalysis. 

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