Laserfiche WebLink
{ <br /> City of Stockton A68106.01A <br /> May 29, 1996 Page A-2 <br /> Samples may be delivered to Twining's chemist laboratory in Fresno, California. The <br /> Twining representative in charge of the field work transport or direct the transportation of <br /> the samples and custody forms to the laboratory, Where the samples are transferred to the <br /> sample control department. A receiving clerk, or an authorized analyst, signs the custody <br /> forms, present a duplicate copy to the Twining representative, and transfers the samples to <br /> a laboratory analyst. The laboratory manager retains possession of the custody forms during <br /> analyses of the samples. <br /> The laboratory manager's responsibilities include monitoring the sample integrity within the <br /> laboratory. This involves assigning each sample a 1 boratory number and maintaining cross- <br /> reference between the sample's field and .lab ratory identifications. The analysts' <br /> responsibilities include maintaining accurate records of the samples analyzed along with the <br /> ` analytical data produced. This involves labelling chromatograms and maintaining the <br /> laboratory numbers on subsamples taken from the submitted samples, labelling glassware <br /> used in the analyses, and properly labelling sample extract containers with each sample's <br /> laboratory number. <br /> Following analyses, the samples are transferred to a limited-access storage room. Chain-of- <br /> custody forms, chromatograms, and other pertinent information are filed for future <br /> reference. Splits of samples analyzed are kept for 30 days. Samples containing hazardous <br /> t <br /> concentrations will be returned to the client for disposal. <br /> A-4 Standard Operating Procedures for Laboratory uali jy Assurance uali Control: <br /> ` These laboratory QA/QC procedures were developed-to reduce outside interferences during <br /> ¢-` analyses of samples. The laboratory director is responsible for creating and maintaining the <br /> program. General QA/QC procedures follow: <br /> • Analytical instruments are servicec on a regular basis to assure accurate <br /> ., calibration; <br /> • Organic-free water is monitored da ly for quality; <br /> • Gas chromatographs are calibrated daily; <br /> • Method blanks are run to check wh ther the glassware and reagents are free <br /> of interference from chemicals that would invalidate the analyses; <br /> i • Standards are prepared using the a 3plicable reference materials; <br /> P <br /> Fj <br />