Sample handling records

All application verification and soil samples must be individually labeled with unique sample identification (ID) and other identifying information such as study ID, test substance name, sample depth, replicate, subplot and date of collection, as appropriate. Proper study documentation requires that sample lists and labels be created prior to work commencing in the field. Water- and tear-resistant labels should be used since standard paper labels may become water-soaked and easily torn during sample handling. Sample lists should have the same information on them as the labels and are a convenient place to record plot randomization, initials of the individual who collected the sample, and date of collection. As such, the sample list is important in establishing chain of custody from the point of sample collection until its arrival at the laboratory. 

Again, in the absence of specific test methods for coal, ultraviolet spectroscopic investigations must rely on investigations applied to other substances with the criteria of sample handling and sample preparation followed assiduously. The practices to be used for recording spectra (ASTM E-169) provide general information on the techniques most often used in ultraviolet and visible quantitative analysis. The purpose is to render unnecessary the repetition of these descriptions of techniques in individual methods for quantitative analysis. 

The field investigator s residue sample handling procedures and equipment are always inspected. It is policy that samples be held at the field locations for only short periods however, accurate records are kept on the storage and handling conditions from the time a sample is collected until it is shipped to the laboratory. The elapsed time from collection until a sample is placed in a freezer must be recorded as well as the location of the freezer and the temperature of the freezer during the storage. The sample storage freezer and the records kept on it are always inspected. 

It is essential to develop a quality assurance (QA) programme that covers sample collection, sample handling, and methods for on-site and laboratory analysis, data handling and record keeping. The QA programme should address the variety of different scenarios likely to be encountered. Appropriate calibration and analytical... 

As IR spectroscopy is a secondary method of analysis, the development of quantitative analysis methods requires calibration with a set of standards of known composition, prepared gravimetrically or analysed by a primary chemical method, to establish the relationship between IR band intensities and the compositional variable(s) of interest. Once a calibration has been developed, it can then be used for the prediction of unknowns, provided two general conditions are met i) the spectra of the unknowns are recorded under the same conditions as employed in the calibration step (i.e., same instrumental parameters, identical means of sample handling, etc.) and ii) the composition of the calibration standards is representative of that of the unknowns. 

Infrared spectrophotometry is a familiar established analytical technique which provides identification of compounds by fingerprint spectra, of which a vast library is available. Both liquid and gaseous samples may be easily analysed and therefore modifications of established sample handling techniques have enabled both GC and HPLC instruments to be readily interfaced. Ideally, scan times of less than 1 s are required to be able to record each peak and peak shoulders. Instrument sensitivity is sufficient so that on the fly recording of spectra can be obtained from GC and HPLC eluants which contain nanograms of sample per ml mobile phase, for example, 10 ng sample in 100 pi GC-IR sample cell. Fourier transform infrared (FTIR) instruments are able to meet these criteria but until recently the instrumentation and computer system have been too expensive for routine use. The new generation of... 

The methods for handling samples to record infrared spectra in a biochemical laboratory are essentially those used in the everyday testing by the organic chemist, with certain exceptions. 

Sample handling and preparation is very easy, as in the case of IR spectroscopy. Commercial instruments belong to two main types, conventional scanning and optical multichannel analysers. The main difference between both types is that, in scanning spectrometers, the scattered light is collected and analysed, usually at 1 cm intervals (channels), whereas in optical multichannel analysers a 300-600 cm section of the Raman spectrum, projected on to the detector, is rapidly recorded in a computer memory without... 

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