OnSite Adulteration Detection Devices for Urine Specimens

Recently, on-site adulterant detection devices have become commercially available. These devices offer an advantage over spot tests because an adulteration check can be performed at the collection site. Peace and Tarani (26) evaluated performance of three on-site devices—Intect 7, MASK™ Ultra Screen from Kacey, Inc., and AdultaCheck 4. Intect 7 simultaneously tests creatinine, nitrite, glutaraldehyde, pH, specific gravity, pyridinium chlorochromate (PCC), and bleach. Ultrascreen tests for creatinine, nitrite, pH, specific gravity, and oxidants. AdultaCheck 4 tests for creatinine, nitrite, glutaraldehyde, and pH. The authors adulterated urine specimens with Stealth, Urine Luck, Instant Clean ADD-IT-ive, and Klear according to the manufacturers' recommended procedures, and concluded that Intect 7 was the most sensitive and correctly identified the adulterants. AdultaCheck 4 did not detect Stealth, Urine Luck, or Instant Clean ADD-it-ive. Ultra Screen detected a broader range of adulterants than AdultaCheck 4. However, in practical terms, it only detected these adulterants at levels well above their optimum usage, making it less effective than Intect 7. However, King (27) has reported that AdultaCheck 4 is an excellent way to detect contamination in urine specimens.

AdultaCheck 6 test strips have recently become available, which can be used to detect creatinine, oxidants, nitrite, glutaraldehyde, pH, and chromate.

Intect 7 test strip for checking adulteration in urine is composed of seven different pads to test for creatinine, nitrite, glutaraldehyde, pH, specific gravity, bleach, and pyridinium chlorochromate (PCC). In our experience, both AdultaCheck 6 and Intect 7 effectively identified the presence of low and high concentrations of PCC in urine. For example, with a low PCC concentration (0.5 g/L), the Intect 7 test pad turned blue from colorless. In the presence of high PCC, the color changed to dark brown. For AdultaCheck 6, the color of the PCC pad turned to purple in the presence of low PCC, and a mustard-green color was observed if high concentrations of PCC were present in the specimen. AdultaCheck 6 and Intact 7 were superior to potassium iodide spot test in detecting the presence of small amounts of PCC in urine. The potassium iodide spot test was unable to detect a low PCC concentration of 0.5 g/L (34). Intect 7 urine test strip has a pad for detecting the presence of bleach in urine. A positive response was observed even in the presence of only 5 ^L of bleach per mL of urine. Such a small amount of bleach cannot be detected by AdultaCheck 6 test strip, because the test for the oxidant was still negative. No change of pH was observed. Moreover, no noticeable color change was observed in the potassium iodide solution after acidification. In the presence of 10 ^L of bleach per mL of urine, the Intect 7 test pad for detecting bleach was strongly positive, along with the potassium iodide spot test (28).

AdultaCheck 6 and Intect 7 test strips were effective for detecting the presence of glutaraldehyde in urine. When glutaraldehyde was present at a concentration of less than 0.4% by volume, neither AdultaCheck 6 nor Intect 7 showed the expected color change. However, at glutaraldehyde concentrations above 2% by volume both urine test strips showed the desired color change in the pad designed to detect the presence of glutaraldehyde.

AdultaCheck 6 has a test pad for determining the creatinine concentration in urine. The possible readings are 0, 10, 20, 50, 100, and 400 mg/dL. The Intect 7 test pad shows a reading of 0, 10, 20, 50, or 100 mg/dL, depending on color change of the test pad. AdultaCheck 6 or Intect 7 test strips can determine a range of creatinine value. The precise concentration of creatinine cannot be determined. Similarly, neither test strip can determine the precise pH of a urine specimen, but can only show the range. However, both AdultaCheck 6 and Intect 7 test strips successfully differentiated between abnormal values of creatinine and pH and normal values in urine as determined by precise measurement of creatinine using the Synchron LX 20 analyzer and pH using a pH meter. When acid or alkali was added to change the pH of urine, both Adulta-Check6 and Intect 7 urine test strips showed the correct trend of lower or higher pH (Table 2) (28).

Comparison of pH, Creatinine, and Specific Gravity Obtained by Direct Measurement and Urine Test Strips in 10 Urine Specimens

Specimen

pH

Specific gravity

Creatinine, mg/dL

Measured

AdultaCheck® 6

Intect® 7

Measured

Intect 7

Measured AdultaCheck 6

Intect 7

1

7.2

9.0

10.0

1.016

1.015

102.7

100.0

100.0

2

6.4

9.0

5.0

1.011

1.005

85.3

100.0

100.0

3

7.1

9.0

10.0

1.015

1.005

101.6

100.0

100.0

4

6.8

9.0

10.0

1.002

1.003

22.1

20.0

20.0

5

7.0

9.0

10.0

1.004

1.005

22.4

20.0

20.0

6

6.6

5.0

5.0

1.013

1.005

18.7

20.0

20.0

7

6.5

5.0

5.0

1.015

1.015

93.7

100.0

100.0

8

4.9

5.0

5.0

1.013

1.015

57.0

50.0

50.0

9

6.4

9.0

10.0

1.009

1.005

60.1

50.0

50.0

10

5.5

5.0

5.0

1.010

1.005

72.1

100.0

100.0

11

6.5

9.0

10.0

1.005

1.005

27.0

20.0

20.0

11 (1:1 dil)

7.0

9.0

10.0

1.002

1.003

13.8

10.0

10.0

11 (Acidified)

2.8

3.0

3.0

1.002

1.003

26.8

20.0

20.0

11 (Alkali)

11.2

11.0

>11

1.002

1.003

27.9

20.0

20.0

12

5.9

5.0

5.0

1.005

1.005

20.9

20.0

20.0

12 (1:1 dil)

6.5

9.0

10.0

1.003

1.005

10.4

10.0

10.0

12 (Acidified)

3.1

3.0

3.0

1.002

1.003

21.1

20.0

20.0

12 (Alkali)

11.5

11

>11

1.001

1.000

21.3

20.0

20.0

Adapted from ref. 28.

Adapted from ref. 28.

0 0

Post a comment