New Jersey Administrative Code
Title 7 - ENVIRONMENTAL PROTECTION
Chapter 18 - REGULATIONS GOVERNING THE CERTIFICATION OF LABORATORIES AND ENVIRONMENTAL MEASUREMENTS
Subchapter 3 - GENERAL REQUIREMENTS FOR FACILITIES, EQUIPMENT AND SAFETY
Section 7:18-3.3 - Requirements for environmental laboratory equipment, supplies, materials, and general instrumentation

i. Each analytical balance shall have a sensitivity of 0.1 mg;

ii. The analytical balance shall be mounted on a heavy, shockproof table. The balance level shall be checked prior to each use and shall be adjusted as necessary;

iii. The analytical balance shall be located in an area that is away from environmental laboratory traffic and is protected from sudden drafts and humidity changes;

iv. The balance temperature shall be equilibrated with room temperature;

v. The interior of the balance housing shall be kept clean and free from spillage of corrosive chemicals on the pan or inside the balance case;

vi. The accuracy of each analytical balance shall be checked once a month using at least two class "S" weights, one in the gram range (five g to 50 g) and one in the milligram range (10 mg to 500 mg). The nominal values of the weight checked, observed weight values to the nearest 0.1 mg, dates on which checks were performed, analyst signature, and other pertinent information shall be recorded in a log book; and

vii. Each analytical balance shall be checked and adjusted annually by a service person employed by the environmental laboratory, or by a balance consultant and a notation recorded in the weight check logbook. A balance which malfunctions between annual checks shall be serviced before being used again.

i. Balances shall be clean and not corroded;

ii. Balances shall tare out and detect a weight of 100 mg when used for general media preparation;

iii. Top loader and pan balances shall be checked monthly against two class "S" weights within the range of use, and a record shall be made of each calibration check in a log book, signed and dated by the analyst; and

iv. Each top loader and pan balance shall be checked and adjusted annually by a service person employed by the environmental laboratory, or by a balance consultant and a notation recorded in the weight check logbook. A top loader or pan balance which malfunctions between annual checks shall be serviced before being used again.

i. The accuracy shall be within +/-0.05 pH units;

ii. The scale readability shall be +/-0.05 pH units;

iii. Both indicating and reference electrodes shall be rinsed with reagent water after each reading;

iv. Samples shall be stirred during measurement at a constant rate, minimizing the air transference at the air water interface of sample;

v. Electrodes shall be stored according to the manufacturer's recommendations;

vi. The meter shall be capable of temperature compensation;

vii. All pH meters shall be calibrated each day of use. This shall include calibration with two standard pH buffers bracketing the value to be measured. After calibration, a standard buffer with pH within the calibration range shall be measured without any control adjustments to check the calibration. All calibration and check data shall be recorded in a log book, signed, and dated by the analyst. When the pH meter is in use for longer than a three hour period, the pH of the third buffer shall be checked once every three hours. If the pH differs by more than +/-0.2 pH units from the standard buffer value, the meter shall be recalibrated; and

viii. Discard pH buffer calibration aliquots after each use.

i. The accuracy shall be within +/-0.1 pH units;

ii. The scale readability shall be +/-0.1 pH units;

iii. A strip chart recorder or electronic equivalent shall be used;

iv. Continuous pH monitoring devices shall be calibrated weekly, at a minimum, using one of the following procedures:

v. Discard pH buffer calibration aliquots after each use.

i. Temperature monitoring devices shall be graduated in at least 0.5 degrees Celsius increments for all analyses except fecal coliform analysis which shall be graduated in at least 0.2 degrees Celsius;

ii. Continuous temperature-monitoring devices shall be accurate to +/-0.5 degrees Celsius;

iii. The liquid column of glass thermometers shall have no separation;

iv. A NIST certified thermometer graduated in at least 0.2 degrees Celsius increments shall be available at all times for use by the certified environmental laboratory covering the complete range for all analyses for which the laboratory is certified and shall be calibrated at appropriate points at or near the critical temperature or range for the temperature being measured. A certificate must accompany the certified thermometer with matching identification number; and

v. The accuracy of all thermometers used to monitor temperatures shall be verified over the range used by comparing the readings of such thermometers with the readings of a NIST certified thermometer in the temperature ranges for which they will be used. A record shall be made containing the identification number of each thermometer, the temperatures displayed on the certified thermometer and the thermometer being verified, correction factors when applicable, dates on which quality control checks were performed, and the name of the analyst performing such checks. Glass thermometers shall be verified yearly and metal thermometers or thermocouples or infra-red temperature measuring devices shall be verified quarterly and the data recorded in a log book, signed and dated by the analyst.

i. Conductivity cells shall have platinum electrodes or be calibrated using a meter with platinum electrodes;

ii. Conductivity meters shall be capable of temperature compensation; and

iii. An initial five point calibration curve shall be established using potassium chloride solutions of various concentrations to cover the necessary range. A single potassium chloride standard shall then be used as a check standard whenever specific conductance measurements are made. The cell constant must be determined and all calculations recorded annually in a log book, signed and dated by the analyst.

i. A household refrigerator may be used for storage of aqueous reagents and samples. For storage of organics and flammable materials, an "explosion proof" refrigerator shall be used. Refrigerators shall maintain an internal temperature between one and five degrees Celsius (34 to 41 degrees Fahrenheit). Thermometers shall be immersed in a container filled with a liquid and placed on one of the shelves of each refrigerator being used to store regulatory samples. The specific temperature of the refrigerator should be at the level necessary to support the handling and preservation requirements of the analytical method or the sample preservation tables of the Code of Federal Regulations incorporated by reference into this chapter; and

ii. The temperature of all refrigerators used for storage of samples, standards, and environmental laboratory reagents shall be monitored daily and recorded in a permanent log book, signed and dated by the analyst. Corrective action shall be taken and appropriate notation made in the log whenever temperatures fall outside the range specified in (a)7i above.

i. Beakers, flasks and other general environmental laboratory glassware shall be made of borosilicate glass that is resistant to damage by heat, chemicals and repeated use. The laboratory shall use only Class "A" volumetric glassware, and need not calibrate it before use;

ii. Unless otherwise specified, borosilicate bottles shall be used for the storage of reagents and standard solutions;

iii. Polyethylene bottles may be used where appropriate for storage of reagents and standard solutions;

iv. Serological or Mohr-type pipets are not volumetric pipets and shall not be used in tests or analysis requiring quantitative sample transfer and measurement;

v. When small quantities of analytical reagents are required to be measured, serial dilutions using class "A" glassware shall be performed. Automatic or digital type pipets shall be calibrated for accuracy and precision on a quarterly basis using reagent water and an analytical balance. Digital pipets shall meet the specifications of Class "A" pipets. The calibration record shall be recorded in a logbook and the record signed by the analyst;

vi. Glassware and metal utensils shall be resistant to the effects of corrosion, high temperatures, and vigorous cleaning operations;

vii. Flasks, beakers, dilution bottles, culture dishes, culture tubes and other glassware shall be free of chips, cracks, and excessive etching;

viii. Plastic items shall be made of clear, inert, nontoxic materials and shall retain accurate calibration marks after repeated autoclaving;

ix. Metal utensils shall be made of stainless steel; and

x. All glassware shall be washed in a warm detergent solution and thoroughly rinsed first in tap water and then in reagent water. If a specific analytical method requires more stringent cleaning procedures, the cleaning procedures given in the analytical method shall be performed.